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American Airlines agrees to purchase Boom Supersonic Overture aircraft (boomsupersonic.com)
403 points by spatulon on Aug 16, 2022 | hide | past | favorite | 515 comments



So they went from scaled down Concorde configuration :

https://www.airway.com.br/wp-content/uploads/2020/10/Boom_Ov...

to a very scaled down Boeing 2707-300 configuration :

https://en.wikipedia.org/wiki/Boeing_2707

(that tiny fin tho...). While reducing cruise speed to 1.7 mach. I see no visible changes to deal with the sonic booms problem. So operation would be like Concorde I suppose, subsonic (or hi-subsonic) over land and Supersonic over ocean only. Unless the super-rich manage the regulation to change.

EDIT : ah yes :) "2x FASTER OVER WATER" and "20% FASTER OVER LAND"...

Also : Maybe good to remember that 18 airlines had once placed orders for Concorde, with only the 2 national carriers flying it in service eventually. And that The Boeing 2707 was ordered by 27 airlines before the program being canceled…


And they still have not solved the problem that ultimately sunk the Concorde. Fuel costs made it unprofitable to operate whenever the price of oil went up.

The small niche of customers willing to pay a significant premium in order to save some travel hours is not big enough to sustain an entire industry of specialized mechanics, parts suppliers, pilots, etc... Basically you need a critical mass of people riding these aircraft every year before the relatively high fixed costs eat you alive, and it's very hard to get a lot of people to buy into a high priced luxury service.


They seem to have dramatically reduced fuel consumption, but fuel wasn't the issue for the concord the limited number of viable routes where.

Going from the Concrods 3550nm range to 4250nm should help with that as it opens up several new routes and longer routes see a more significant drop in travel times.


Still there are not much other routes you can go supersonic in one flight but trans-atlantic, which Concorde could do. Trans-Pacific which could have been the big money making route, like LAX to Tokyo, you need to be able to do 4737 nm... which makes the 4250 nm just short to make it. They would face the same problem the Boeing 2707 team had (or even Lockheed with the L-2000 project), no matter how they tried, too short range for trans-pacific in one Hop. So they would have had to make a stop to Hawaï, but then what's the point if you can take first class in a B777 and make the journey shorter in one subsonic flight. All other routes would be over land, and there again you can't go supersonic (for time being).


Seattle to Tokyo is only 4144nm so that might be a viable route especially for routes that would have already had a layover in LAX and/or Tokyo.


In part that will depend upon its ETOPS capabilities, i.e. how far it can be trusted to fly after an engine fails. The Great Circle mapper is fun for playing "what if" games with potential routes: e.g. here's the direct Seattle-Tokyo routing with dark shading showing parts where flying for 60 mins at 410 knots wouldn't reach an airport. So if that was the ETOPS performance for a Boom aircraft (and I've no idea; I just picked a B777 as an example) then the route would have pass a little closer to Alaska and Sakhalin to keep the possibility of a safe diversion at all times, and that in turn might make the route too long.

http://www.gcmap.com/mapui?P=KSEA-RJAA&MS=wls&DU=mi&E=60&EV=...


For those who don't know, ETOPS = "Engines Turn or Passengers Swim"

j/k, it stands for "Extended Range Twin Operations"

https://www.caa.co.uk/commercial-industry/aircraft/operation...


Quad-engine jets are automatically ETOPS-180

https://www.boeing.com/commercial/aeromagazine/articles/qtr_...


Going to North America via Dubai or Qatar is a big route industry.


Fuel prices were absolutely an issue for Concorde. BA struggled immensely with the Arab oil embargo and the per-seat cost for the Concorde shot up into the stratosphere and ticket sales collapsed.


We can easily model this in a sheet. Like this one: https://docs.google.com/spreadsheets/d/1JhvGd6iVWNweMM-PYk3z...

At todays Jet 1 A US fuel price of $3.07 per gallon it would cost $108k to fill the Concord. Which holds 120 passengers. That comes out to a cost of $900 per person passenger on a full fight.

If the cost of fuel were double like a few months ago then that cost would be $1,800 per flight.

Compared to a Boeing 737 which has a fuel cost of ~24k at max capacity of 7,878 gallons at todays prices. A passenger limit of 177 and a fuel cost as low as $136.64 per passenger on a full fight.


Meanwhile a one way ticket cost US$975 in 1977 or inflation adjusted about 4,700$ today. Which increased faster than inflation so by mid 90’s your talking around 6,000$ which is something like 12,000$ today.

Thus fuel while expensive wasn’t a deal killer over most of it’s history as long as they could keep most seats filled.


The "as long as they could keep most seats filled" was a deal killer though.

There was enough demand for one return flight a day carrying a small proportion of the overall passengers on the immensely-popular with wealthy people JFK-LHR and JFK-CDG routes. That wasn't enough to utilise the 14 production aircraft properly, never mind enough demand for it to have been viable as an airframe programme ...


They both also used it for private charters which was apparently quite a profitable business. Anyway, the exclusivity was presumably more profitable than simply maximizing occupancy.

That said, boom is building a significantly smaller aircraft which should again open up more possible routes.


The Arab Oil Embargo was 1973-1974 and the Concord didn't go into commercial service until 1976. While it sounds like the oil crisis had an effect on airlines placing Concord orders it didn't overlap with the commercial service being offered to the public. See:

https://en.wikipedia.org/wiki/Concorde


The oil embargo hit the entire industry hard, but Concorde continued operation into 2003. Over time as other aircraft became more efficient the efficiency gap grew much larger but it was still profitable up to Air France Flight 4590.


Concorde survived on government subsidies, especially with the R&D costs, but also the maintenance chain. It was a point of national pride for the UK and France, but also a money pit for both countries.


> Concorde survived on government subsidies, especially with the R&D costs, but also the maintenance chain.

Yes, and this was mostly necessary because of the small unit counts and small number of routes, not because of fuel costs (though the latter certainly did not help.

Both could be significantly better with Boom: more routes, and lower fuel costs.


From what I've read, the Concordes had preferential landing treatment on westbound flights into JFK and Dulles, due to their shortage of fuel, and the controllers would often allow them to land before other planes that had been queuing for a while. (They used a separate controller radio frequency apparently for the initial request, and then switched to using the main frequency).


I wonder how much larger the population of people is today (vs Concorde's era) that are willing to pay for these supersonic ticket prices. 3x? 10x?


This could be a very important enabler. As you can see in other "luxus" industries, the amount of affluent people on this planet has ballooned. I don't know any numbers, but I got the impression that the private airplane industry had a strong growth in recent years. And flying supersonic with an airline for sure is way cheaper than any private flight.


Will that also be the case if they actually have to pay for the carbon they emit in the process?

Currently airline passengers don’t have to pay for their carbon emissions, but I doubt that’s gonna last for much longer (we are in an emergency after all). And I’ve seen elsewhere in this thread that the emissions are likely gonna be somewhere between 5x and 10x of normal sub-sonic flights. The price of this extra carbon emission will probably be something that even affluent passengers will want to skip.


Good question. Currently fuel for international flights isn't taxed at all, as far as I know. Which explains the popularity of flying. Fuel for cars costs several times more, at least here in Europe.

Starting to tax airplane fuel would be an important step towards reducing the CO2 output. Possibly that would trigger a switch to synthetic and carbon neutral fuels.


It’s less than 2% of global CO2 emissions. If your tax scheme shaved off 15% of demand, you’d be saving 0.3% of global CO2 emissions—equivalent to a few months of global emissions growth.


The thing is that we have failed miserably at reducing our carbon emissions, and we are simply out of time at the moment. Any action we do is already too late. All we can do now is mitigate the worst effects.

There will be a global cost scheme for carbon at some point in the future. I hope it will be a simple tax (imposed by each state by some international agreements; although some weird cap-and-trade scheme with limited effect is probably more likely given how governments are behaving) and I wouldn’t be surprised if it is mostly in effect by the time Boom plains are in commercial operations.

Whatever the scheme there will probably not be an exception for international flights (I’m guessing countries will be focusing their efforts on exempting their militaries). The thing is that every industry is going to try to get a discount, and that is simply not possible (we are in an emergency after all). So it doesn’t matter if it only shaves of 0.3% of global emissions (which honestly would be a disaster and not acceptable in the long run). What matters is that all industries (except the arms industry; lets be realistic here) will have to suffer equally for their sustained pollution.


No, of course not. This is for us, the plebe.


It’s like 2–5 million people with more than $10 mm. Regionally correlates with real estate and equities.


I’m not sure that it would even be larger now than before.

Subsonic flight has become much more efficient, cheaper and when paying for higher class, more comfortable. This is one of the reasons often mentioned for the economic demise of the concorde. The audience willing to pay $6000 on a concorde ticket, could now spend $4000 on first class subsonic with a seat that fully reclines into a bed. They can fly a little longer at night but sleep the whole journey.

Wendover did a good economic analysis of the concorde: https://youtu.be/n1QEj09Pe6k


The number of people who will pay--or can make their companies pay--$500+/hour for a handful of saved hours on a flight which mostly won't go into incremental productive work is miniscule. Most business travelers aren't international lawyers or consultants flying across the Atlantic for a quick get together. But pay a bit more to fly a bit more comfortably to be more rested/as a perk and maybe even save on a hotel room night? Quite a few people, even if not the typical traveler.


I wonder how much larger the population of people is today (vs Concorde's era) that are willing to pay for these supersonic ticket prices. 3x? 10x?

At least.

Even if you think price is a barrier, think about how many more millionaires and billionaires there are in America and Europe today than there were just 20 years ago.

Tack on our society's rediscovered fascination with conspicuous consumption ("influencers"), and I don't think filling seats will be the problem today that it once was.


Sounds like a 1970's mindset that is wildly underestimating how much air travel has changed and how many more hundreds of millions of people can now afford semi-frequent air travel, with hundreds millions more in the pipeline.


Most of whom have demonstrated, time and time again, that price is the primary factor by which they decide who to fly with.


Business travel, which continues to explode between the West and Asia, is far less price sensitive and far more time sensitive. And of course the number of wealthy air travelers continues to increase rapidly as well.

Plus, it's just f*cking exhausting to fly 10-18 hours, so people may well be willing to spend more on those extra-long-haul flights just to spare their mind and body. I don't believe any commercial supersonic jets were even able to fly trans-Pacific in the past, and ties between those regions were a tiny fraction of what they are today anyway. Faster trans-Pacific transport simply seems inevitable.


Agreed - if it could stroll right across the Pacific it would be compelling. But unfortunately Boom needs to stretch its legs a further 25% to manage LAX - China, or about 10% for Tokyo. An A350 takes about 9 hours to fly as far as Boom's range, which is a longish but not utterly brutal flight.


Didn't the founder say he envisions supersonic tickets to be $100? I can't even buy any subsonic tix for less than $120.


I can envision teleportation.


This is hilarious, if true. I flew on a shitty subsonic flight from the midwest to Utah earlier this year and it was $450/ticket when I bought them 6 months out.


I flew on a shitty subsonic flight from the midwest to Utah earlier this year and it was $450/ticket when I bought them 6 months out.

I flew 2,000 miles between the Midwest and the west coast last week. $109 each way, with checked baggage, booked three weeks out.

I like Utah, but let's not pretend that your flight (or mine) is representative of anything.


Still, you have to admit that 100 USD is in no touch with reality (if it was actually said).

We are talking about a plane that will burn much more fuel (which they claim will be carbon neutral) and fly a fraction of the passengers per trip, on routes that are already very competitive. 100 USD will only be a heavily subsidized fare at best. In reality the cost per route will much more likely be far higher.


Here in south-eastern Canada it used to cost $800 to fly 180km to fly from my town to Halifax. Now I see it's only around $300 to $600.


The other big problem here is that it would only be useful for trans-oceanic trips (i.e., international). This is American Airlines.

Who in their right mind wants to spend top dollar to fly internationally on an American airline, worst of all AA, one of the two worst airlines on the planet?

Anyone with some money who wants a nice international flight is going to take one of the Asian or Middle Eastern airlines, not one of the shitty American-run airlines. The level of service is so far superior it's not even funny. AA is infamous for their horrible service in First Class.


Isn’t that the point of the purchase? A differentiator for this market?


Maybe, but I don't see how it could work. It's like Walmart trying to sell luxury products to billionaires. The regular customers won't afford these luxury products, and the billionaires sure as hell aren't going to shop at Walmart. AA is the Walmart of airlines (or worse); anyone with good taste isn't going to buy a ticket from them for any price, no matter how fast the plane is. These planes aren't going to be that much faster; why bother with shitty AA service when you can get a ticket on one of the Asian airlines or Emirates instead and enjoy high-quality service?


>>> Miami to London in just under five hours

I know I would pay a premium for this experience. Simply because it fits into my imagined jet set lifestyle phenomenally well. Maybe once every two years for a special occasion or treat ;)

I also think the economically limiting term is still the turbine blades. Lifetimes for commercial service turbines run 100k+ hours. Supersonic is maybe 1/10 that. And have higher rates of oxidation, cavitation, catastrophic fatigue, etc. We need a new Alphafold! For phase stability of alloys exhibiting high strain resistance at high temps and fast cycles...


We now live in an era of conspicuous consumption and wealth concentration. Maybe the right time for overly expensive air travel


Over water isn't too bad a problem as many major routes (e.g. US - Europe, US - Asia, US-Australia, Asia - Australia) are over long stretches of ocean.

But will the range be there? Concorde was severely range limited, which somewhat defeats the purpose of faster travel (if it only works on medium length routes).

Cutting a 14hr SYD-SFO flight down to 8.5hrs is just more impactful than cutting a 7h LHR-JFK flight down to 4.2 (when taking into consideration significant time at the airfields for taxi, boarding, security checks etc)

Concorde didn't have the range for long haul and once you need to land to refuel you lose all time savings.


Overture is being designed to carry 65 to 80 passengers at Mach 1.7 over water — or twice the speed of today’s fastest commercial aircraft — with a range of 4,250 nautical miles. Optimized for speed, safety and sustainability, Overture is also being designed to fly more than 600 routes around the world in as little as half the time. Flying from Miami to London in just under five hours and Los Angeles to Honolulu in three hours are among the many possibilities.

Probably will be very expensive but it's exciting for future possibilities


>Probably will be very expensive but it's exciting for future possibilities

Are you kidding me! I cant recall the last time I DIDN'T need to be in Honolulu in THREE HOURS!! This is a life changer for my Macadamia nut Addiction...

---

In all seriousness, the best commercial prospect for this is high-speed-cargo.

Need a part from GuangZhu like TODAY?

Need an organ transplant from Ohio to Munich, TODAY?

Need to fire 900 employees via ZOOM call whilst flying to your other mansions to feed your pet slaves, TODAY?

Possibilities are boundless!


Flying from Chicago to Tokyo or LAX to Hawaii is borderline traumatic. Getting those flights from 20 hours down to 8 would be a huge improvement.


> a range of 4,250 nautical miles.

> Need a part from GuangZhu

CAN-LAX is 6,284 nm.

> Ohio to Munich

OK that can work, CLE-MUC is 3,759 nm.


> CAN-LAX is 6,284 nm.

Just add a refueling stop at ANC, the same as most cargo flights today (and the same as most passenger flights in the past).

According to a Great Circle mapper, CAN-ANC-LAX is only about 250 km longer than CAN-LAX.


Descending and climbing again will take a lot of fuel, jets are only efficient at high altitude. Plus of course the extra takeoff and landing adding cycles to the airframe.


Sure, but if it's the difference between "can" and "can't"...

It's a small enough issue that it's the routine route for cargo flights between China and the U.S. West Coast.

Anchorage is the second-largest cargo airport in the United States (after FedEx's home base in Memphis).


Part of that is because cargo usually runs on old and inefficient planes, so they really benefit from “intermediate stop operations”. Carrying all that extra fuel for a direct long-haul adds 10-15% in fuel costs.


CLE-MUC also has about 1/3 of the route over land, which you’d have to fly subsonic.


Ah pffft, those are other people problems. Wealthy people want to get around quickly.

What’s a few shattered windows and waking up entire states with bangs at 3am? They shouldn’t have chosen to live under a flight path between an organ donor and recipient.


Maybe fly up Lake Erie and Ontario, then cut across New York, New Hampshire, and Vermont? You still end up over land for that last part, and you're going to rattle windows in Niagara, but it probably cuts half an hour off of the trip or so, maybe a little more.


I FUKN LOVE that someone on HN spent the effort to determine if my BS was airport-code ready.

God, I fn Love you.


Interesting that this is slower that the Concord which cruised at Mach 2. I wonder if a slightly lower speed makes the economics more sustainable.


Boom were previously targeted a cruising speed of Mach 2.2, I wonder why they lowered it to Mach 1.7 with the latest design update.

Might be related selecting an engine. The previous version of the design had a fantasy engine that didn't exist (I think the specs came from a military engine that they couldn't use due to export restrictions), but now they are working with Rolls-Royce, and appear to have actually selected an engine design. It must be smaller than what they originally wanted, because they moved from a 3 engine design to a 4 engine design.


Supersonic heat also. Concorde was in Aluminum and at 2.1 mach it was at the very limit of what could be done in aluminum. Which required a very "tight" design, engineering marvel in fact. Go faster and one have to go for titanium, which is much more difficult to work with and manufacture.


Didn't the Blackbird weep jet fuel because the seals couldn't hold when the skin was at ambient temperature?

I heard they put enough fuel in it to take off and get up to temperature and then refueled it in the air for safety reasons.


Export restrictions are not just messing cryptography!


Maybe military engine control systems work by sending PGP-encrypted emails to the fuel valves?


But helping mute the airforces of Russia and China


To me that sounds like a fuel saving option. Might extend the routes.


If this is achieved without afterburners (as I understand it is), then yes, this is an immense difference in fuel consumption and radically impacts the economics.


Concorde only used afterburner(en_us)/reheat(en_uk) for a small part of the acceleration phase of the flight not for cruise.


It's en_gb and not en_uk (although UK is exceptionally reserved [1], and we recently begun using UK on car nationality identifier stickers).

[1] https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2#Exceptional...


GB is the more neutral term, UK is pushed by the Conservatives and nationalists/royalists


GB is not "more neutral".

Great Britain is the name of the post 1707 Union of England and Scotland. It's not neutral if you are a member of the Unionist community in Northern Ireland.

The United Kingdom is the name used by the country at the UN but is, of course, not neutral if one is a member of the Nationalist community in Northern Ireland.

No one uses .co.gb domains.


Here .... en-ie and en-gb are different things, because the Irish English dialect is a bit more distant from British English than the Scottish one. Whereas .uk is a country code representing a specific political entity.


GB is not more neutral - it excludes Northern Ireland, which is a part of the UK.


Aside from any such associations, they mean different things.

People often use the terms imprecisely, but (for example) if Scotland were to leave the United Kingdom, it'd still be part of the island of Great Britain.


It doesn't seem very neutral to go around demanding others call you great.

Yes I know.. that's not how the word is meant in this context...


Afterburner is a common term in both countries. Reheat is and always was a semi-official slang used in the UK and is a reference to the similarity in concept to reheat steam turbine.


Note that Concorde "B" was meant to use a variant of the Olympus 593 without reheat, but ultimately lack of sales of the original aircraft doomed it.


It used afterburners for takeoff and accelerating through Mach 1.


Well past Mach 1 actually, reheat was cut off at Mach 1.7.


So afterburner then. 'Merica.


it's all turboprops and no afterburner. so, expensive, but much more affordable than concorde, maybe to the point of competing with subsonic first class


Turbofan (what's on most commercial jet aircraft), not turboprop (jet engine driving a propeller, generally on smaller commercial and some private aircraft).


ah, neat! looks like they recently switched from 3x turboprop to 4x turbofan

edit: had to correlate sources to find that a bunch of popular aviation blogs got the original design wrong. was actually 3x turbofan -> 4x turbofan


Everyone claiming you are wrong hasn't bothered to google. Literally the first response for "overture turboprop" is a series of articles confirming what you said.

> The Overture supersonic aircraft will be powered by three turboprop engines, which includes two that will be mounted under each wing, while the third engine will be fitted at the end of the fuselage.

https://www.aerospace-technology.com/projects/overture-super...


It really must be a simple typo, it's inaccurate to the point of being nonsensical.


It’s like claiming an upcoming Tesla model will use Ni-Cd batteries. No matter how many blogs claim it, it's clearly wrong.


There is no way you could go supersonic with a turboprop


You can, it's just so loud it becomes health risk to even share a runway with it: https://en.wikipedia.org/wiki/Republic_XF-84H_Thunderscreech


To save others the click: that plane never reached super sonic.

What makes the turboprop itself supersonic is the blades are traveling super sonic. Normal turboprops are limited by keeping their blade tips below super sonic to prevent booms and vibration. It is not special to go super sonic at the blade tips, this experimental plane only served to confirm that.

So it is correct to say no turboprop plane has ever gone super sonic and the idea that boom is turboprop powered is wrong on its face.


That plane didn’t go supersonic. It is impossible for a propeller driven aircraft to go supersonic.


Maybe in a steep dive ? ;-)


Well, it'd be impressively noisy, anyway.


if your next stop is tbe pavement and its a one time use aircraft...


Just the tip...


they're right after all—many blogs got it wrong. maybe boom's PR screwed up


it was never a turbo prop. You'll never get a propeller driven aircraft to supersonic speeds.


And if you try you end up with monstrosities like the XF-84 Thunderscreech

https://en.wikipedia.org/wiki/Republic_XF-84H_Thunderscreech


"Unlike standard propellers that turn at subsonic speeds, the outer 24–30 inches (61–76 cm) of the blades on the XF-84H's propeller traveled faster than the speed of sound even at idle thrust, producing a continuous visible sonic boom that radiated laterally from the propellers for hundreds of yards. The shock wave was actually powerful enough to knock a man down; an unfortunate crew chief who was inside a nearby C-47 was severely incapacitated during a 30-minute ground run. Coupled with the already considerable noise from the subsonic aspect of the propeller and the T40's dual turbine sections, the aircraft was notorious for inducing severe nausea and headaches among ground crews. In one report, a Republic engineer suffered a seizure after close range exposure to the shock waves emanating from a powered-up XF-84H."


Even if your aircraft doesn't come close to the speed of sound, the tips of the propellers will, leading to insane amounts of noise. The Russians, as they are prone to do, didn't care and did it anyways. https://en.wikipedia.org/wiki/Tupolev_Tu-95


A max speed of 575 mph is quite impressive for a prop plane; hasn't ever been recognized by FAI though...


why the downvotes? the original design was trying to use 3x turboprops, and i can see articles on google about them switching to 4x turbofans after the xb-1 work

edit: see parent edit, i was wrong. you guys are pretty good at making someone with misinfo feel bad though


I think the logical explanation is that there was a mistake in the original article. A propeller is not the right choice for supersonic flight, I don't want to say impossible but it wouldn't be far off. They've gone from 3 jet engines to 4, and in both cases they would be turbofans.


The XF-88B Turboprop hit Mach 0.9 in level flight, but it was using an afterburner, which is rather cheating. Supposedly it could go supersonic in dives.


acknowledged in edit


You have to be mixed up; a turboprop has a propeller attached to the jet engine. No-one in their right mind would use a turboprop supersonically. It would make an insane amount of noise.


> a turboprop has a propeller attached to the jet engine.

Since this is the pedant thread I feel obliged to point out that turboprops are propellers attached to gas turbine engines, not jet engines. Jet engines are gas turbine engines that produce thrust using a jet of hot exhaust gas out the back. Gas turbine engines that don't produce thrust using a jet of exhaust gas aren't jet engines; examples are turboprop engines and turboshaft engines (popular in helicopters, some tanks, etc.) Turbofan engines produce at least some of their thrust with an exhaust jet, so it's fair enough to call those jet engines. Probably the truest sort of jet engines are turbojet engines, which are no longer used for commercial aviation and only have some niche applications remaining (for instance cruise missiles.)

Then there are the "jet engines" which aren't gas turbines at all; jetskis use gasoline powered piston engines to produce thrust using a jet of water. And rockets, which don't breath air, could be called jet engines in a sense because they produce thrust using a jet of exhaust gas. But if you go around calling rocket engines "jet engines" you're going to get a lot of people correcting you by pointing out that rocket engines don't breath air. Many rocket engines do contain gas turbines though, using gas turbines to power propellant pumps, e.g. turbopumps...

And if we really want to get into the weeds, some piston powered aircraft get a small amount of thrust from their exhaust too. And some exploit the "Meredith effect", wherein air over the radiators gets heated and produces a small amount of thrust. These effects may contribute a few percentage points of the total thrust of the plane, and in truth, some turboprop configurations do this too. But >90% of the thrust is coming from the propeller, not the exhaust.


That is true, I was restricting my vocabulary to avoid adding additional concepts.


Define “right mind”

The Republic XF-84H "Thunderscreech" was an American experimental turboprop aircraft derived from the F-84F Thunderstreak. Powered by a turbine engine that was mated to a supersonic propeller, the XF-84H had the potential of setting the unofficial air speed record for propeller-driven aircraft, but was unable to overcome aerodynamic deficiencies and engine reliability problems, resulting in the program's cancellation.

[. . .]

Unlike standard propellers that turn at subsonic speeds, the outer 24–30 inches (61–76 cm) of the blades on the XF-84H's propeller traveled faster than the speed of sound even at idle thrust, producing a continuous visible sonic boom that radiated laterally from the propellers for hundreds of yards. The shock wave was actually powerful enough to knock a man down; an unfortunate crew chief who was inside a nearby C-47 was severely incapacitated during a 30-minute ground run. Coupled with the already considerable noise from the subsonic aspect of the propeller and the T40's dual turbine sections, the aircraft was notorious for inducing severe nausea and headaches among ground crews. In one report, a Republic engineer suffered a seizure after close range exposure to the shock waves emanating from a powered-up XF-84H.

The XF-84H design top speed was Mach .9 and probably made it to .7 in testing.

https://en.m.wikipedia.org/wiki/Republic_XF-84H_Thunderscree...


Replying since I can’t edit my other post. I didn’t downvote you, I just let you know that you were very likely wrong and that may have been the source of downvotes. I presumed it was a statement made in good faith and was going to be corrected in short order and it has.

It’s the original source of the mistake that should feel bad as they’re supposed to be experts in the field.


The original design was meant to use 3x turbojets, not turboprops.


What does "turbo" mean in this context? Are these things somehow using exhaust to spin a turbine to force air into the intake faster for boosted performance? Or is it just jive, spin, marketing, to sound cool?


The XB-1 used 3 turbojet engines.


i didn't say anything about xb-1's propulsion


I acknowledge that; I was trying to bridge from the things you did say to facts about the Boom aircraft development.


Share the links?


Not sure what you were thinking of, but they were never planning on a turboprop since that's not really possible.


Since we talk about a start up selling power points to VCs, why not use tirboprops? Same as having typos in Nigerian oil prince inheritence mails to weed out the targets, sorry investors, that might think too much?


I find it incredibly hard to believe that turboprop was ever on the table.


r/noStupidQuestions ;

Can these be 'stacked' - Can you have a turboFan in line with a turboProp such that the output of the wash of the Fan feeds into the Prop, but with a portion of the wash spinning to thrust on the outer ring of output.=, via a design in the cowlings which is hyper directed thrust vents (think the grid of straws used to funnel water into a cohesive column, which can be directed)

Imagine a small diameter turboprop behind a much larger turbofan


Technically yes but it would make performance worse. Props are efficient because of their large size, which allows them to push a lot of air, if you shrink it then you give up that advantage. If you had extra power left over to turn a prop, you'd want to use it to turn a bigger fan, or just leave that power in the exhaust.


As far as has ever been discovered - no, this won't work. You can think of a fan as just a prop enclosed in a housing (jet engine). A prop loses effectiveness at the speed of sound because the air passing the prop gets a high pressure shock wave that effectively makes the prop not prop-shaped, so it can't move air. Picture it as using a hammer on glass instead of pushing on glass with your hand, one works way better than the other for generating thrust. The only way (so far) to have an effective prop is to have the prop tips move slower than the speed of sound. Engine designers worked around this by slowing the air down around the prop. To do this, they moved it inside a tube. They slowed the air down so that the prop (fan) can travel more slowly, and then they heat the air behind the prop to gain excess pressure and thrust. And this is exactly what a mach 1+ jet engine does. The opening at the front of the engine forces air in, and the design of the inlet slows the air down so it is subsonic, along with a corresponding increase in pressure. Some fans (props) which are now effective because they spin at subsonic speeds compress it more, so more air can enter the engine. Then they burn fuel to heat up the air, increasing the pressure. After that they have a few more fans that run in reverse to drive the fans at the front of the engine, and finally exhaust this hotter, bigger, more high pressure air out the back of the engine to produce thrust.

So hopefully you see how your question is an interesting one, and one that has already been sorta done. Turbofans and turboprops are really quite similar, but at mach speeds only the turbofans have the right environment to be able to work efficiently. Your idea would have the prop in a supersonic air stream, which would make it effectively useless.


>a high pressure shock wave that effectively makes the prop not prop-shaped, so it can't move air.

Leading micro eddys can solve this.

If the induction is a straight stream, it will fail - you need to direct micro eddys

If you do this with mechanical means (deflection cowlings) you will hit a limit.

The ideal design is in the funneling of eddys as they traverse in a super spiral between the front eddy and as it spirals to the thrust vector.

however, pre-ionizaton, and then magnetic ion direction can swirl the eddy to the desired output. However, AIR is not the thrust component at this time, its ionized energy which is being "thrust" (thrust is typically thought of as a 'push' - but this is actually a 'pull'

Identify a spot, pull yourself to it. As opp


What about the Tu-95? It's famously loud due to (says Wikipedia) supersonic propeller tips. Do you know why they're still effective?


I am convinced that if you were to dimple the propeller (tips) such as a golf ball is pitted, you would reduce this effect.

Further, if you wer to dimple/convex in an alternating pattern the leading edge of any aero ... efficiencies would increase.

Micro-dimples are better.

Understand the eddys, as Da vinci would say....


The Tu-95’s props are paired for counter-rotational torque balance. The second prop does not add additional thrust.


The supersonic speed was the question, not the contrarotation.


Well, samstave's original question was one of adding power with an inline stack. As I understood it, that isn't the purpose for he Tu-95's pair of props since they share a power source. The below explanation [0] has some interesting analysis based on Russian language documentation about how torque is divided between the prop pairs. Additionally the paper linked from the Wikipedia contra-rotating prop page "Analysis of a contra-rotating propeller driven transport aircraft" [1] has a great section on fuel savings, which probably has contributed to the Tu-95's success.

Thus, the front prop gets almost 20% more torque than the rear prop.

0. https://aviation.stackexchange.com/questions/74787/why-dont-...

1. https://www.rcgroups.com/forums/showatt.php?attachmentid=281...


Thank you all TIL so much.


I believe they're sacrificing efficiency for performance.


Edit: removed battery voltage analogy.

You might be interested in reading this stack overflow answer about differences between turbo prop, jet, and fan. https://aviation.stackexchange.com/questions/71301/what-is-t...

Another aspect to consider is changing engine characteristics for different conditions. An example is changing the structures guiding air into the engine.

https://en.wikipedia.org/wiki/Intake_ramp


This is why we CAN have nice things.

If everyone were to take their response as if they were educating a youngling, to grow with an understanding, the world would be a better place.


Why would you do that though, instead of just running a multi-stage turbofan such as they used on the F-100 engine (F15 and F16).


"can" vs "can come up with an implementation that provides any performance benefits in any set of real world circumstances"

You could. But there's no way the efficiency and complexity penalty having props feeding fans or fans feeding props comes out ahead of "pick one and make it bigger"


When I saw “all turboprop and no afterburner” I imagined some new flavor of “all cat, no cattle”.


i hate when cowboys wear the cat but don't actually work with cattle


Ok I'm assuming the parent was a typo (???). And the original is "all hat, no cattle" I guess, but I feel like I've heard the saying "all hat, no cat", is that a thing? Because there was a cat in a hat, and it rhymes, so it basically still works as a saying.


Not only very expensive, but basically coach class all the way through, even for the rich people.


Rich people value time highly. Coach-class that gets you somewhere quickly can be worth a lot more than first-class that takes twice as long.


Still, flying westbound fast makes tons of sense as you can arrive "before" you took off (local time) and thus you get a whole day in front of you.

But eastbound makes a lot less sense, unless you're just trying to save time. Because flying at night eastbound won't make you gain much compared to a regular red eye and flying during the day, you'll land at night...


It always makes a lot of sense - time saved is time saved.

Flying east fast after a day of meetings means you get in bed on time.


No it doesn't. You are forgetting timezones.

The above poster is correct - supersonics are suboptimal for eastbound, especially when you consider they can only be used at speed over the ocean.

A super sonic flight that leaves JFK at 6PM arrives at 2AM in LHR after 3 hours of flying plus a 5 hour time zone change.

It's much more optimal to take a lie flat seat on a traditional aircraft, get a decent nights sleep on the flight, land at 7AM, shower at the lounge, and charge forth with the day.

My view is that the lie flat bed is really what made supersonic obsolete, and I see Boom as largely a folly.


As somebody who flew quite a few lie-flat business flights on JFK->LON - you absolutely do not get good night sleep. Flight time is 7:30 and you can realistically go to sleep 30 minutes after take off (when they start serving food and other passengers are still noisy - good luck falling asleep quickly) and you are generally woken up about 1-1.5 hour before landing (Why? I have no idea but they turn on the lights, serve breakfast and do announcements about weather in London about that time before landing). So you get at most 5.5h of mediocre quality sleep which is better than nothing but not enough to function 100%.

3 hour flight will change a lot of things for JFK-LON business trips as they open up opportunities to loose only 1 full day during business trip instead of loosing two full days. I generally stay on NYC time with meetings in the afternoon LON time if trip is less than 5 days so short flight is game changer.


If I’m a jetlagged businessman in NYC, operating on internal London time, and I’m finishing my work day at 6PM local time/11PM internal time, I want to get home and wake up with my family ASAP rather than try and sleep on a plane.

Thank goodness for Zoom


It's true, and makes sense where your face-to-face time is the key thing. But where it's just "work time", surely you can do a good amount of work on a 7 hour flight in a decent business class seat with reliable internet? Especially if you can also minimise the time wasted on the ground (fast security line, lounge with areas to work, airline calling your flight when it's almost finished boarding not at the start, etc.).


There are definitely people who can get work done in a flight, but honestly I have a hard time imagining logging 7 hours. Maybe if you have a lot of reading to do?


I do too, but I also don't have a huge amount of experience sitting in an incredibly comfortable first class seat. I imagine I'd get a lot more done than I do in coach.

I think if I had a decent internet connection (happening more and more) and comfortable seat I'd happily take a 7/8 hour flight over a 5 hour one in a coach-style seat.


I fly first class a fair bit, and I struggle to get anything done on the plane (in the terminal is fine, though).

For me, there's no way to take a good break on a plane. I can't really get up and stretch my legs (unless you try to pace the aisle), and any kind of distraction is going to be on a screen.

It is more comfortable than coach, but it's still not really comfortable. Coach is actively uncomfortable, first class is just kind of neutral; not actively comfortable or uncomfortable.

I usually get more done sitting in the terminal than I do on the plane itself.


I fly business a few times a year and almost always treat it as rest and relaxation. The chance for quiet downtime that I won't get on the trip and rarely get at home as well. 10 hours of extra sleep, reading, and podcasts. It seems like most passengers do the same thing. Trying to smash actual work into the flight is miserable.


For me, it's a good chance to watch a movie and maybe read a book (which I don't do often enough at home). I'm may be an outlier but I don't really care if I have Internet on a flight or not.

If I have a lie-flat business class option with decent food, getting to my destination a few hours early with less comfortable seating isn't a clear win. Like most people, I'm not jetting over to London to have lunch and sign a deal and heading home to sleep in my own bed.


> Like most people, I'm not jetting over to London to have lunch and sign a deal and heading home to sleep in my own bed.

Thank you for enlightening me. As someone nowhere near rich enough for this to be relevant, my upper bound for pleasant W-E transatlantic flight is being able to sleep. Shortening that sleep seems like a loss. But if you have a private jet on call, you can skip connecting flights, airport security, schedules, and all the things that actually make flying slow and miserable. I guess this company is aiming at the people who don’t quite have that kind of money.


There is, in general, a very big gap between private and cost-doesn't-matter commercial. And, no, I can't speak to what flying private is like.

Flying can still be a hassle flying business/first mostly because of cancellations/schedule changes--which can still happen otherwise because of weather, air traffic, etc.--but is less frequent I assume. A lot of the hassles of commercial flight (security lines, lack of overhead space, airport crowds in the waiting area, cramped seating, etc.) can be mitigated to a significant degree however.


Yeah I feel like the fact that there are N screens all over the place is a huge distraction (even when I'm trying to relax!)

Just having somebody watching transformers in the corner of my eye... on a flight a couple of years ago I watched 2 bollywood movies start to finish cuz the lady in the row in front of me was watching it and I couldn't help just watching on her screen.


Depends on the airline, lots of planes have bars you can walk to.


I'm the same, but I'm imagining the "super serious business people" who are presumably the target market for these planes (given the price). Is it worth the premium to get them from London to NYC in 4 hours, when they could do 5 hours of billable work in the lounge/on the plane anyway.


Depends on how well you can sleep I guess. US to Europe is almost entirely overnight flights.

Not so much the other way though.


Airplane wifi is garbage and wildly unreliable.


Getting better in my experience, last flight I had about 1-2Mbps which was plenty for browsing and sending messages/emails. If that's all you require to do work, then it's fine.


Every now and then it's not awful, that's true. But it's just entirely non-functional and/or extremely slow a high percentage of times, which means you can't reliably plan to have functioning wifi, which means you can organize your schedule around it.


Also sanity. I’ve done a 16 hour flight before, and let me say never again. I slept for half of it and the other half was still miserable.


On those lengths you start to go a little crazy. I've done Atlanta to Tokyo and back before, and those are 13+ hours depending. You sleep and wake up and sleep and wake up, watch movies, and then wonder why there's still so many hours left to go.

It does make me appreciate human engineering though. When you think about all the parts that work correctly day in and day out to have these longs flights run back and forth nearly non-stop.


> On those lengths you start to go a little crazy

100% this. After 16 hours, I could have kissed the ground when I walked off that plane. At some point, after maybe 8-10 hours, order seems to break down a bit. People stop caring so much about keeping clean, the plane starts to get really cluttered and nasty, food ground into the carpet. I feel for the cleaning crews that have to spruce up the interior after a really long international flight.

I still remember the first time I flew home from the north, we had taken off from Dubai and were headed to Seattle, which goes over the north pole. I watched that silly map more than I should have (it just makes things slower, I'm sure...) and I was so elated the moment we went 'feet dry' over North America. And then I realized that we still had six plus hours to go, more than if we were starting at the east coast. I was so sad for a few minutes I could have cried.


The Seattle to Dubai flight is rough, but at least it's usually on a nice plane.

The worst flight I've had in a long time was a British Airways flight to Nairobi. Not actually all that long a flight to Nairobi from London, but BA uses their "This plane is definitely about to be decommissioned" planes on that flight. The panel between the cabin and the fuselage came loose when I nudged it with my foot and slid down into the hold, so I spent the whole flight with essentially all my possessions wrapped around me, certain that anything I dropped would vanish into the void.


> order seems to break down a bit

Haha, yes. At some point people stop caring. You see people mulling around, getting their own food and drinks - just anything to pass the time.


I live in Colorado, but am from Melbourne, Australia. I told everyone the last time I went back that it will be the last visit. That trip is hellish and once every 2 years is still too much.


Try adding a break in Honolulu. It is indeed a long flight from Los Angeles but I found it's bearable if you spend a few days in Honolulu. Also, Jetstar-Melbourne can be very cheap in economy or it can be a very good price/value in what it calls business which really is just premium economy in today's transcontinental flights.


Before the pandemic saved me from ever having to do it again, I was traveling from Portland to Hyderabad twice a year, and I told my manager that I wouldn't go back unless I could stop over in London for a day before continuing on to Hyderabad. Never did find out if that would have been accepted or not, but I was so tired of that particular three-flight nightmare.


Maybe Starship can turn that trip into under an hour in the future.


I'm not sure why this is getting downvoted. Point to point travel on Earth is one of the proposed uses for spacecraft.


I didn't downvote, but it seems unlikely that either of GP's endpoints will ever boast spaceports.


Melbourne is on the coast so an offshore platform will work on that endpoint. New Mexico has a spaceport already. Baring one opening up near Denver, flying to the west coast and then taking a Starship would be possible.


I'll take your word for it with respect to Melbourne, which is a lovely city I thoroughly enjoyed several decades ago. "Spaceport America" is a silly boondoggle that will never launch an orbital flight and will eventually be absorbed into White Sands missile range. Getting from anywhere in Colorado to any populated location not in Colorado takes longer than an hour. b^)


Yeah, those take at least an additional day to recover from.


I find planes impossible to sleep on. End up arriving over tired and stiff and sore after my 16 hour flight. I've never got my company to spring for a better class though. Next time I'm taking a 1 day layover in Germany or something.


That moment when your body really understands that it is in fact 1 or 2 in the morning, but you can't sleep on a plane. I'd nod off repeatedly, only to instantly wake back up again. I'm quite jealous of people who can just conk out on a plane, but it does not work for me.


I don't think I could sleep for 8 hours on a plane


The business class lay flat seats are pretty comfortable. I was able to sleep 8-9 hours on them, but was interrupted sleep. Better than nothing.


Try doing 24 hours, with a 9 month old.

It was not fun.


I actually did 30 with a 2 year and a 2 month old. The young one is easy actually, they are in a bassinet and sleep most of the way. The 2 year old was much more a problem. She was just under 2, so didn't have her own seat, was obviously getting bored and her sleep rhythm was completely different to mine. Still was OK though.


As someone who flies first class there is no way I'm flying coach to save time. Flying business is about the lounges, the meals, the service, and the ability to stretch out your legs.


As someone who flies coach everywhere, I’d do the same if I had the means to do so. A long flight in coach is extremely draining even if you’re time-focussed, you’ve got to take recovery time into consideration.


If you value that over speed, why not take a oceanic cruiser? More lounges, more service, you can stretch your legs way more (or take a swim), better meals (and more of them)..

Its always a tradeoff of comfort vs speed.


It's not as much of a tradeoff as you think. I've been on cruises and would rather be first class on Emirates or Qatar Airways than on a cruise.


The internet tells me that there is only one ocean liner left (Queen Mary 2), which travels only between the UK and the US east coast.


There's only one left because there is no demand for that kind of travel, which is good evidence that people value time over comfort.


There's certainly demand for low-cost ocean voyages as vacations, with over 300 cruise ships in service (and cruise lines generally quite profitable).

It's high-cost, non-vacation, long distance travel/transport where ocean liners were beaten in the 1960s by airliners (and airlines, in contrast, are generally not very profitable).


Still, that solitary transatlantic liner carries more people across the Atlantic in a typical week than Concorde did when it operated scheduled services on that route, and not because the other Concordes were busy elsewhere...

In any case, the lack of senior business executives choosing seven day trips in plush private cabins as their preferred mode of transatlantic crossing isn't much of an indication of whether people in that price bracket will tend to prefer pay more to spend four hours in discomfort rather than eight hours mostly asleep.


She's the only one in service right now, but looks to also currently depart from Australia, the Emirates, France, Germany, Hong Kong, Singapore, and South Africa.


The Queen Mary 2 (at least pre-pandemic) did a combination of transatlantic liner routes and cruises depending upon the time of the year.


That's true mostly of "rich people" who are also highly scheduled executives. Otherwise there are a lot of tradeoffs involving comfort, time, schedule, and so forth.


If that was the case, wouldn’t we still have Concorde or something similar?


Makes me wonder if BOOM will ever enter the private jet market.


Maybe that will be their go-to market once they realize tgat airline business is actually incredibly hard.


Three hours from SF/LA to Hawaii would have a ton of takers at a premium price even at coach class. It makes that trip doable for a long weekend.


At just under 5 it already is, I know a few people who do it. Hawaii is a bad example because its very much a leisure market. They can barely make business class work with recliners let alone a Concorde replacement. That’s why they put their worst business class on the route.

This will end up running LAX-JFK-LHR in my opinion.


Would they be allowed to go supersonic for LAX-JFK?


No, that route is over land.


Ah yes, I should have said 'I see a potential market for faster premium air travel on both the LAX-JFK legs and the JFK-LHR legs within the range of the Boom plane' - you are of course correct that they would not be able to fly LAX-JFK supersonic.


Between PA and LA there are not a lot of populated areas so strearing around them should be possible.


14 CFR Part 91.817, in essence, prohibits anyone from operating a civil aircraft at a true flight Mach number greater than 1 over land in the United States and from a certain distance off shore where a boom could reach U.S. shores.

https://www.faa.gov/newsroom/supersonic-flight


Concorde was not very pleasant to sit in from what I've heard. Great food, but the seats were basically economy 2x2.


This was something I always heard before I experienced it but the truth is it wasn't so bad. You definitely weren't sitting in a full First Class seat (which were smaller in any case back then) but it was still perfectly comfortable especially for the relatively short duration.

And because the overall experience was so cool -- board directly from the lounge, the led display showing how fast you were going, seeing the curvature of the earth (sorry flat earthers), arriving before you left, etc. -- you never thought about the seat. I'm sure if you took it all the time you might care but most people it was awesome.


The Concorde was more or less what domestic business/first class is today which is pretty much what first class was internationally as well back when the Concorde was flying. (Maybe a bit more cramped--more like what's being called Premium Economy on an airline like United these days.)


There is a Concorde on display at the Museum of Flight near Seattle. You can walk down the aisle but the seats themselves are protected by plexiglass.

The seats do look very cramped and the windows are very small.

The museum of flight is amazing and much more interactive than most air museums.


The windows are so small because Concorde cruised at 60,000 feet. At that altitude the usual oxygen masks won't keep you conscious. The windows are small so that if one ever failed, Concorde could descend fast enough to an altitude where the masks would work before the pressure dropped too low.


I've tried the seats at the Intrepid museum. They are very tight and the window is tiny. I'm sure the food and drinks helped.

https://www.intrepidmuseum.org/The-Intrepid-Experience/Exhib...


When my dad was flying back and forth to Europe from the US East Coast a lot, he told me he got upgraded to the Concorde once for some reason. His reaction was that it was a neat experience but he'd just as soon fly first class in a 747.



I recall all the crazy designs that were shown before the A380 came out, bars, entertainment areas etc.. Unsurprisingly airlines instead opted to put more seats in (well Singapore did implement those suites with a bed, but that was it). These interior concepts never become reality because of the economics. They look nice in investor brochures and airline magazines though.


Interior will depend on the line.


When the choice is a two day business trip flying in business class or a one day trip in elevated coach class, lots of people will choose the option that has them back on the same day.


> coach class all the way

Has there been a render of the interior or something?


There is on the Boom site, and it certainly doesn't look like regular cattle class

https://boomsupersonic.com/static/images/overture-experience...


Yes and pre-launch renderings of the interior of the Dreamliner featured a piano bar and all-round led screen walls.

Interior buildout in planes is always at the discretion of the airline, and the concepts shown by manufacturers should not be taken as realistic.


I can't see how that seat could possibly transform to lie flat and it's a dud if they try to get people to pay big money for non-lie flat seats.


I guess the idea is that the trip is such a short hop that you don't need to lie flat. For example train seats in first in the UK aren't lie flat either, because they're only ever a few hours at most.


I'm not sure lie-flat is a must if the flights are so much shorter. I'd rather have a comfortable seat for working if we're only talking about a 3 hour flight.


The luxury is saving time.


> over water

All the imagined routes are over large bodies of water. Is it key to the functionality or intent of the aircraft in some way? Why not NYC to LAX in 3 hours?


When space shuttle Challenger broke up over Dallas, Texas about 20 years ago it came in really low (steep angle of attack) and there was a sonic boom, felt like a garbage truck had driven into the side of the house at full speed. Woke me up from sleep at about 6am. Got out of bed to see what was going on, turned on the TV to find out it was the space shuttle.

People will tolerate a sonic boom once a quarter or so, but you've better have a really good reason, like national security.


> When space shuttle Challenger broke up over Dallas, Texas

That was Columbia, not Challenger. Challenger exploded on launch from Cape Canaveral.


Supersonic booms are extremely loud. Without solving that problem, these can not be flown over populated areas.


It’s currently illegal to fly past Mach 1 over land barring a few exceptions (eg: military training areas).

https://www.faa.gov/newsroom/supersonic-flight


Something I didn’t know about the sonic boom until discussions of this company is that it is continuous, not just at the point the plane passes the speed of sound. So a plane like this is constantly dragging a cone producing very loud noise behind it.


There has been some research in trying to minimize or at least spread out sonic booms by changing aircraft shapes and engine dynamics, but as far as I know they're all still experimental. Boom is going to live up to its name if it ever actually flies, which means staying over the water whenever they are operating in the supersonic regime.


Due to noise constraints supersonic flight is banned over land right now. If they lower noise pollution maybe laws will be changed.


A bunch of replies say that wouldn’t be allowed, but I heard sonic booms regularly while living near an Air Force Base in California. It didn’t seem to affect the hundreds of thousands of residents nearby. Is there an actual reason why we can’t have one every day at 10am or on some other regular schedule?


If you heard USAF sonic booms, they were probably over 15 miles offshore, or 15 miles inside an Air Force training range. They were probably not directly over your house.

A crosscountry scheduled supersonic flight will have to overfly populated areas twice a day - booming all the way.

(Something that causes a lot of confusion - people often think a sonic boom is an instantaneous thing that happens when the plane breaks the sound barrier - it is not, it’s a continuous shockwave that travels with the aircraft while it is flying above Mach 1; anyone on the ground who the shockwave passes over along the flight path hears a sonic boom)

If you’ve ever heard thunder from lightning 15 miles away compared to thunder directly overhead, that might give you some framework for figuring out the difference.


I remember growing up during the cold war in western Germany which was formally under the control of the allied forces. So they were allowed to go supersonic with the military jet aircraft and frequetly did so, even in rather populated areas (by German standards - in general, Germany is much denser populated than the US). It was a bit annoying but definitely survivable (here I still am).

I think it was a mistake for the US to ban supersonic flight outright and especially at all altitudes. I can't imagine a sonic boom being a huge problem, if you are 10 miles up or higher.


It really depends on where the sounds were generated, in my experience. Off shore sonic booms are loud, but fairly tolerable by the time the sound makes it to the beach. But I once heard two fighters go supersonic directly overhead in eastern Washington (they were pretty high up, even so) and the booms sounded like someone tried to bash in the front of the house. Not something you'd tolerate with any regularity.


I imagine because it’s a lot harder to successfully sue the USAF.


Because of the sonic boom, you can't be flying over inhabited areas. Regulations prohibit that.


I believe supersonic flight is currently banned over the USA (and most countries?).

A previous entrtant in this area seemed to suggest that efficiency dropped near mach 1, but then rose again to 95% at speeds around 1.4 so being able to stay at that speed may make it cheaper to run and maximize their USP of speed.


This is not a winning proposition. Even if we presume these will fly from a VIP terminal so the time you spend at an airport is low, you still need to get there. I just can't see everyone being flown in and out on a helicopter but maybe my imagination is stunted. Once you begin to add up those hours, you are just not saving enough time for the surely astronomical cost.

You'd need a much longer range for this to be a real win. If you double that range then you can do JFK-SIN or PTY-SYD and then you could do an LHR-PTY-SYD flight in ~12 hours which would be a massive win.


Boom Supersonic is targeting current business class seat costs per mile. So it‘s not Concorde level crazy.


You can target any price you want, if you achieve it is a different story. All eVTOL companies arw targeting prices below taxi rates and have yet to proof thatvthey can actually do it.


> This is not a winning proposition. Even if we presume these will fly from a VIP terminal so the time you spend at an airport is low, you still need to get there. I just can't see everyone being flown in and out on a helicopter but maybe my imagination is stunted. Once you begin to add up those hours, you are just not saving enough time for the surely astronomical cost.

This is true for getting to JFK from Manhattan, which is 40 minutes with 0 traffic and then the airport is absolutely massive and has long lines, but Boston -> Logan or SF to SFO is minutes. I think my total time from my door to my gate is ~30-40 minutes when I fly SFO.


Shaving off enough hours to be able to board a plane in the early morning, have a two hour business meeting in the destination and fly back and arrive home in the late evening of the same day is a huge draw to some.


Except it doesn't really work. It could almost work flying west then east to get home but regular Concorde flights couldn't give you the option to fly back the same day.

BA001 LHR 10:30AM -> JFK 09:25AM

BA002 JFK 08:30AM -> LHR 05:15PM

AF002 CDG 10:30AM -> JFK 08:15AM

AF001 JFK 08:00AM -> CDG 05:45PM

That's why flying westbound supersonic is less of an advantage. Because as you can see, flying west, your day is still wasted, even if you leave early.


Seems doable if the schedule was tweaked though? LHR 9:30AM - JFK 8:25AM, JFK 1:30PM - LHR 10:15PM


You're right but I'm sure both companies had good reasons for their schedules (for instance noise restrictions at night).

And realistically, from your plane at JFK to Manhattan, that's got to be a least an hour and a half (immigration and cab/limo). And assuming you'd have to be at JFK just an hour before your flight (and for an international flight that's ballsy), plus with transportation still taking an hour, you just wasted 3.5 hours commuting forth and back to the airport.

That schedule wouldn't work unless you flew to Manhattan. And even then, it'd be tight.


Just use Blade helicopter service - 10 min to Manhattan starting at $200+ so affordable to whoever can afford business class. Still tight for one day meeting but if LHR flight was at 8:00AM and flying back a bit later at 2PM NY time it's possible.


I expect operators would arrange dedicated/express facilities for all the airport stuff to speed up the experience. Dedicated/priority check-in, security, immigration. What would be the icing on the cake is an express train from the airport to the city centre that runs every 10-20 minutes (for all passengers prepared to pay, not just supersonics).


That train is the Heathrow Express, just need the JFK equivalent and you’re sorted!


That would be the Long Island Rail Road (at 35 minutes). (It's also connected by subway, which will take 60 minutes to Manhattan but maybe worthwhile if you want to get off sooner.)


First class into JFK on Pan Am used to at least have an option to fly into NYC by helicopter. Originally this was to the Pan Am building in midtown was switched to the midtown heliport after an accident.


a "reasonably" priced helicopter service already exists in nyc, I don't see why this would be so crazy.


You are arguing with a straw man. Nobody said driving to the airport will change. The claim is for the price of business class, get there in half the time.


What I am saying is that you can only save so much on the flight time over such a short range when the overall trip has fixed time segments. If we were looking at shaving off seven hours of a 20-21 hour London-Sydney trip then yeah, that's massive even if the flight itself is merely 19 hours of that.


In other words, running into Amdahl's Law [1]

[1] https://en.wikipedia.org/wiki/Amdahl%27s_law


I think Boom's entire business plan is that they can do supersonic passenger jets for not astronomical cost. It's not like they're unaware of the Concorde.


Melbourne to LA flight is currently 13-16 hours. This plane would cut it to around 8 if they could extend the range and it would make the flight bearable (I find that first 8 hours are OK but anything after that slowly turns to agony). But the distance between Melbourne and LA is 6883NM and even Brisbane to LA is 6246NM. So, Australia is still out of reach. One could do Brisbane to Honolulu at 4088NM and then Honolulu to LA but with the layover total time will probably be the same at best or much longer. Maybe one day...


How are they doing this with sustainable energy?


Can someone do the math on how much sustainable energy we would be wasting so people could get somewhere faster than a normal plane?


Wind resistance is supra linear naturally, but its also a more aerodynamic plane than a normal one, but also carries less passengers.

Its prolly something like 5x-10x worse.


Good Lord.


https://www.iata.org/en/programs/environment/sustainable-avi...

I wonder if designing for synthetic fuels gives them any benefits? They can be a little bit purer.


biofuels or synthetics. not sure if they plan to own the fuel supply chain, so "net zero" may come through offsets to cover the impact of producing the fuels


Biofuels is ecological fraud. It is not sustainable. And is there a synthetic fuel plant with zero impact at any scale already? No, this is just wasting more fuel for the heck of it.


I can imagine the deserts eventually covered in glass tubes to grow algae for fuel and be sustainable if they can figure out a sustainable nutrients part.


Are you saying that sustainable synthetic fuels can't exist? Or don't current exist? Because those are two very different statements.


Both of those statements are false: synthetic fuels exist now. Last I checked you could buy synthetic fuel for about 2-3 times what regular fuel of the same types cost. Germany was doing synthetic fuels in WWII. South Africa did them when under embargo for their racist policies. Now they are mostly used by racers - where allowed they are enough better to make a win against regular fuel (assuming great drivers and well tuned cars).


The statement was sustainable synthetic fuels. Synthesizing from other fossil fuels like coal or natural gas definitely doesn't qualify.


Maybe, but all you really need is a source of CO for the process to work. Coal or natural gas are easy sources, but with some energy input we can make it from CO2, Photosynthesis is the most obvious way.

Sustainable really depends on how much we need. There is probably enough wind energy for the process, so long as we only use it for things where high energy density is needed. That means drive an EV car or electrified transit, but we can use synthetic fuel for airplanes. Maybe, this last is mostly my guess, it is a real problem to work on.


Well, it requires a lot of power, so building a large plant will be difficult and expensive.


> building a large plant will be difficult and expensive.

Utility scale renewables are in pennies pwr kWh in Levelized Cost, and continually dropping.

There are 10kWh/liter of jet fuel. Utility scale solar is 3c/kWh LCOE today.

Assuming a pessimistic 10% efficiency in electricity to synthetic jet fuel conversion via H2 hydrolysis and the Fischer Tropsch process, that's a hypothetical $3/liter of synthetic jet fuel.

Current petroleum based jet fuel is $1.50/liter.

If you improve the conversion efficiency to 20% and lower the LCOE of utility scale solar to 1c/kWh (projected by 2050), and the hypothetical liter of synthetic jet fuel drops to 50c/liter, all while petroleum jet-fuel grows increasingly scarce and more expensive.

The efficiency of synfuel production could rise significantly as the efficiency of feedstocks like H2 hydrolysis (already 50%+) increase, and if if CO for Fischer Tropsch can be sourced from biomass instead of sourcing it from atmospheric CO2.

Finally, it's likely that in the future we'll switch to using hydrogen directly as an aviation fuel, bypassing hydrocarbons altogether, at which point the electricity to air conversion efficiency nears 80%.

At those prices, you can begin to afford to overbuild renewable capacity to drive a synfuel pipeline to store that energy chemically, which we will arguably need to do for seasonal energy storage anyways.


On top of what danans calculates, they are currently researching solar reactors that convert biomass directly into biofuel with sunlight, skipping the losses and costs of converting sunlight to electricity with regular PV solar.


> is there a synthetic fuel plant with zero impact at any scale already? No, this is just wasting more fuel for the heck of it

cool, so you're on board with nuclear + hydro as a more sustainable base load solution than lithium-based batteries


I would love a future where we are making everything nuclear, including synthetic fuel. However this is nowhere near reality. You need high temperature reactor to make this viable.


Lithium based batteries don't produce power.


Did replygirl say they did? To my reading they are talking about using batteries to store and deliver baseline energy from intermittent sources like wind and solar.


this


They appear to have signed a deal with YCombinator startup Prometheous Fuels to supply the SAF fuel, with carbon offsets to cover other carbon costs.

https://www.prometheusfuels.com/

(very cool website, not sure if thats a good or a bad thing)


> (very cool website, not sure if thats a good or a bad thing)

Maybe I'm just old-school, but this was sooooo annoying. It'd be a cool intro to a Telltale game or something, but having it take over all the navigation (scrolling barely works, getting to the point takes forever) to tell its fancy 3d story was just a waste of my time, IMO. I want to know how their fuels work, not that they can hire someone to make a 3D game intro inside their browser. Just unnecessary shiny that gets in the way of usability :(


Cool site indeed. Unfortunately (but expectedly) experts are challenging the feasibility of it: https://www.technologyreview.com/2022/04/25/1050899/promethe...


carbon capture to fuels is pretty cool! wonder how much of the capture will run off gas or battery :|


stupid lip service


Strong FOMO settling in. Premium transatlantic routes routes like NYC-LHR are super important to the bottom line of the big legacy carriers. If one airline has supersonic and others don’t that could be a huge blow to the others.

Of course things didn’t work out that way with Concorde, which was not commercially successful and more of a spectacle than something founded in business fundamentals. But if Boom can make supersonic passenger travel economics work out it would certainly be hugely disruptive.


> If one airline has supersonic and others don’t that could be a huge blow to the others

I think it's going to come down to exactly how fast or slow this is, the price, and what the hard-product (eg the seats) are like. A modern First Class is a very, very comfortable way to travel, and other than the novelty value, I'd certainly rather spend 8 hours in lie-flat that 5 hours in a recliner. That'll also depend on the time-of-day of the flight -- worth saving the time perhaps if you're traveling East-to-West, but for West-to-East might as well just overnight it?

Long story short, I think it'll have use-cases, but it's not like Concorde -- when Concorde launched, 1st Class over the Atlantic looked a lot like 1st Class inside the states now -- comfortable, but not somewhere you wanted to spend a lot of time


Modern International First is going the way of the dodo on many routes, because business is now more comfortable than first was in the past.

Knowing this, Boom is allegedly targeting an equivalent cost per mile to a standard business class seat.


While I don't have the 1st class experience, I recently went overnight with a sleeping train, and was unlucky to find the slower 7 hour one already full, so I had to go with the faster one, which only let me sleep for 5 hours, leaving me a bit dazed at the train station at 5am.

Sometimes speed isn't better :).


My personal hypothesis is that Asian and cross-Pacific traffic has grown considerably in the decades since Concorde was flying and I look forward to wealthy eastern markets keeping the supersonic market viable. If American and United don't figure it out I could see a gulf country carrier or Singapore Airlines making it work.

I haven't looked into profitability yet but a quick look at the list of busiest routes shows that Asia dominates the list. https://en.wikipedia.org/wiki/List_of_busiest_passenger_air_...


Agree that this would be important except that there's basically ~no work being done on supersonic trans-Pacific flight. Boom's design doesn't have the range to operate trans-Pacific, and AFAIK there has never been any supersonic passenger aircraft (built or designed) that has had the range to pull it off.

I do agree though, LHR-JFK holds very little fascination for me. It's a relatively short flight with a lot of ground-side overhead time, so the benefits of Going Very Fast seem pretty minimal. The prospect of SFO-HND or LAX-ICN very fast though seems a lot more appealing.


Yeah. You can/could get JFK (or EWR) to LHR (or LCY) without a red eye. Not sure what routes exist these days though I've taken EWR to LHR in time for a late-ish dinner in the city quite a few times. It's a long day but even in Economy Plus seating, it's not much longer/less comfortable than flying coast to coast.


I flew DUB-NYC-SEA recently, and honestly DUB-NYC on an a320 was a lot more comfortable than NYC-SEA on a 737…


The leaked United / Apple data[1] from 2019 was an interesting data point for this demand.

At the time, Apple was booking 50 business-class seats a day just between San Francisco and Shanghai.

That's one company, on one route. Representing one segment of demand.

Certainly, things are likely to change with the effects of Covid, but I think there's a lot of substance to your perspective.

[1] https://9to5mac.com/2019/01/14/united-airlines-apple-biggest...


Boom would be lovely for LAX/SFO to Singapore if the range allowed it. That could take some of the higher end traffic away from middle eastern carriers to the region.

I don't see it doing so well for the middle eastern markets, ultra long hauls on average spend a lot of time flying over land (minus the Australian flights) - for example, see LAX-DXB whose only water crossing is the arctic ocean, where supersonic might not be allowed for ice preservation purposes https://flightaware.com/live/flight/UAE216/history/20220815/... , DXB-Tokyo which is almost entirely land: https://flightaware.com/live/flight/UAE318/history/20220815/... , or DXB-Cape Town, which again is mostly over land: https://flightaware.com/live/flight/UAE772/history/20220816/...


Concorde also didn't work out for management reasons and generated most revenue right before retirement when they they finally lowered ticket prices and stopped flying them half empty like the absolute idiots they were.


Interesting, I had heard the opposite. BA did a survey of passengers and realized that most passengers had no idea how much the tickets were worth since their employers had purchased the tickets for them. They thought their employers paid more than they actually did, so BA realized that they could considerably increase prices without losing many customers. BA raised prices and finally started turning a profit on Concorde.


As I recall Concorde was something like 30% over first class. Which was very expensive at the time.


The way I heard it was that prices were 30% over first class but passengers thought that prices were 3X the cost of first class. Worst of both worlds -- price sensitive travellers wouldn't even bother checking out Concorde as an option, and price insensitive travellers weren't paying as much as they were willing to pay.


Do you have a source for this? Like other folk who have replied, this is the opposite to my understanding, at least from the perspective of BA (I know nothing about AF). heritageconcorde.com[0] talk about almost 20 straight years of profitability:

> Concorde earned £500 million for British Airways after tax profit, this was between a loss making 1982 and a highly profitable 2000 with just seven aircraft. The first profitable year was 1983 (£14 million) increasing to £54 million in 1987. BA had good and bad years, in 1992 they actually even made a small loss, but then quickly returned to profitability. Immediately before the crash the profit levels were running at nearly £60 million and could have returned had they kept flying. (Even the last 6 months of operation in 2003 netted £50 million profit).

And:

> With unprofitable routes mounting, Concorde was going through rough times in the early 1980s. At this point, British Airways made a move that potentially saved supersonic travel. In 1981, British Airways managing director Sir John King managed to purchase the Concorde fleet from the British Government outright for £16.5 million plus the first year’s profits. Following the purchase, British Airways increased fares, bringing Concorde routes closer to profitability. With the fleet now owned outright, British Airways added additional routes.

[0] https://www.heritageconcorde.com/concorde--british-airways


For AF, my understanding (and my source actually worked that side of the business) is Concorde got profitable with special flights (aka people renting the plane to travel the world) not from just your regular scheduled flights.

But keep in mind neither BA nor AF really paid for their fleet...


Really? I thought it was exactly the other way around: Concorde was initially underpriced, and only started making money once pricing was yanked up to what the market would bear.


United also has a deal with Boom, that was June this year.

https://www.bbc.com/news/technology-57361193


>Overture’s order book, including purchases and options from American Airlines, United Airlines, and Japan Airlines stands at 130 aircraft. Boom is working with Northrop Grumman for government and defense applications of Overture.


That deal was June of last year (2021). They've been advertising the upcoming service in-flight since last summer.


There was also signage in O'Hare I think last time I passed through. Struck me as odd.


A few years ago BA specifically excluded the idea of supersonic travel because you can provide a much more comfortable sleeper service at a similar price while making more profit.


LHR is capacity constrained right now so they don't have slots to add more flights. Hopefully the runway expansion will be finished by the time Boom airliners are actually in service.


American would swap this in for a plane which is using an existing takeoff/landing slot. Heathrow is also passenger-capacity-constrained right now, but that's more to do with understaffing.


> American would swap this in for a plane which is using an existing takeoff/landing slot

Have to be charging a great deal to the small number of passengers for it to be worth swapping in to a fully loaded 777 spot


Move all the first pax to the boom aircraft and do all economy/premium economy in the 777 and you’d come out even in the number of seat miles available.

You could also upgrade a couple of the 777-200 or 787 routes to a 777-300 to get more seat miles to offset those lost to loosing a slot to a smaller aircraft.


> Move all the first pax to the boom aircraft and do all economy/premium economy in the 777 and you’d come out even in the number of seat miles available.

That's still two aircraft instead of one, which means acquiring another slot.


Oooohhhh. Yeah that wasn’t super clear.

American already has several slots into LHR. I counted 24 arrivals into LHR tomorrow.

One 777 all economy plus one Boom aircraft all business is roughly equal in seat miles to 2x 777 (first + business + premium economy + economy).

An upstart airline would need to acquire a slot to get a new aircraft into LHR. However American could add a super sonic aircraft to its service and still maintain the number of the seats it has going in. Yes, it would have to take one aircraft out, but there are enough pax that will be connecting and can be sold a different routing that it can use flexibility with seat configuration to not be limited by slots.

For American, a bigger factor is probably what kind of seats they can sell. For instance, DFW->LHR has a 75% load factor tomorrow for first class but a 68% load factor for economy class. However, later in the week economy has a higher load factor.

Those first class seats are a lot more profitable than an economy. Adding first class seats while taking away economy seats is profitable if you can fill the first seats.


Very true; I think the Overture is meant to be 50-55 seats? If so that's basically just the First/Business cabin of an American 777-300. If each of those 55 seats are paying a premium on top of sub-sonic business class, maybe that's enough to "lose" the remaining ~240 seats.

Edit: Apparently Overture is 65-88 seats depending on configuration.


LHR is not the only airport in London.


> LHR is not the only airport in London.

No, but it’s the only airport in London that the big US legacy carriers - American, Delta, and United - fly to.


Connections are important. Also runway length; Heathrow, Gatwick and Stansted are probably the only ones long enough.


It would truly be a game changer if this could fly out of LCY. A faster BA1 has always been my dream flight.


That is some wishful thinking there


> Optimized for speed, safety and sustainability

I hope any airline that gets these gets punished by all the other customers for the environmental irresponsibility of pushing this gass gussling technology.

Wow, you can blow through your whole annual carbon budget in only 4 hours!!


> big legacy carriers

Who are the new “non-legacy” carriers in this setting?


>American has paid a non-refundable deposit on the initial 20 aircraft.

I guess that's not nothing given how these sorts of contracts usually give the big name brand company lots of outs if the speculative company goes bust, but by bragging about it without specifying the amount, I'm guessing it's a low amount.


Companies love low cost R&D that doubles as low cost marketing!


Also I'm assuming it is hard to do this kind of project internally because it seems so cool. A lot of employees would be upset if they were not allowed to take part.


Not that American Airlines ever was in the business of developing or building aircraft in the first place.


I will say that I’ve seen plenty of “non-refundable” contracts in this industry (see Qatar’s ongoing tiff with Airbus over coating peeling issues) result in either side unilaterally cancelling delivery of airframes. It would really come down to what exactly went wrong whether or not AA could truly couldn’t claw that deposit back.


I'm pretty sure it's nonrefundable from the stance of AA can't just change its mind and get its money back. If Overture fails to deliver on certain metrics, I'd be willing to bet AA has a refundable out.


Exactly - but my guess is that plenty of those metrics are assessed before delivery, such as type certification.


Not a lot to go on here. Boom projects first flight in 2026 for the Overture. They seem to be fairly close to first flight with their XB-1, but it has not flown yet. I congratulate them on getting funding, but all the hard parts are ahead.

https://en.wikipedia.org/wiki/Boom_XB-1


Awkward... The website FAQs still say "XB-1 test flights are planned for early 2022."


Way more delayed than that. Once upon a time, they were planning on test flights in 2017. Then 2018. Then 2019. Then 2020. Etc.

https://interestingengineering.com/culture/boom-xb1-superson...

https://www.denverpost.com/2017/06/20/centennial-boom-supers...

https://www.flightglobal.com/strategy/paris-boom-xb-1-schedu...


XB-1 is a prototype plane for R&D. It's target first flight now is fall 2022.

Overture is a production model for commercial operations.


Ehich measn, technically and legally, XB-1 isn't an aircraft. As pointed out elsewhere, the hard stuff is up ahead. Cudos so for BOOM for having customers signed on, something a lot of eVTOL companies only managed to do very recently.


By 2026, with the typical delay till 2028 they’ll face the prospect of Earth-2-Earth starship flights


Given that Starship hasnt even had its first unmanned orbital test flight yet, getting man rated and ready for commercial flights by the general public within 4-6 years seems unlikely.


yeah, id put that in the 30s, thers a lot more risk there.


earth to earth starship flights are way away and will be vastly more expensive. Plus more risky. You are lifting that giant ship up into space.

It must be less efficient than a winged flyer - even a fast one like boom's, because it won't need so much energy to get out of the atmosphere like a starship has, right? I want starship to succeed but I'm guessing it will be so much more expensive and risky.


They still don't have an engine that allows them to fly supersonic...


Boom's original bet was that they could use better aerodynamics and materials to get supersonic speeds using existing engines. This saves a ton of time and money since you don't need to get the engines certified. The prototype uses three non-afterburning GE J85 engines[1], which produce 2,950 lbs of thrust each. It should have a top speed of mach 2.2.

The main issue is that their production aircraft will need more powerful engines, and modern civilian airliner engines have large fans, high bypass ratios, and high compression ratios, all of which make them difficult to adapt to supersonic flight. It looks like their plan is to collaborate with Rolls-Royce to build a suitable engine using an existing engine core. I hope they can pull it off.

1. https://en.wikipedia.org/wiki/General_Electric_J85


Lots of airlines also preordered Concorde: https://en.wikipedia.org/wiki/Concorde#Sales_efforts


> At the time of the first flight the options list contained 74 options from 16 airlines:[44]

14 commercial aircraft were delivered of 20 total.


Thought it was an acquisition. Maybe change headline to “purchase aircraft from”


I was speaking with one the top managers of Airbus and asked him about Boom Supersonic and the Overture. He was skeptical of the idea mostly because of fuel consumption. He said based on their research, the future of flight is slower not faster. Open fan, hydrogen, and electrical planes all point to a slower and more efficient aviation.


Let us all hope. It's hard to imagine any future at all where this planet starts adding newly inefficienct means of travel. That there might be a market for faster travel is no comfort.


Mhh, whenever I heard about them, I looking at their current successes. Did they not promise to launch a sub-scale supersonic plane to test out everything? It has still not flown unless I have missed something.

So why should I trust that their main airliner is anywhere even close to on-time.


Do we really need to go somewhere so quickly? There needs to be a line somewhere where "getting to the other side of the planet in less than 12 hours is unsustainable and environmentally horrible".

I've learned to appreciate slow-travel using trains and have been a supporter of electric planes for reaching further places.


Some people want to live and work in different places.

Rather than high speed rail to get the masses into cities for work, we are getting fast planes for the wealthy to work in NYC and spend the weekend in European villas.

Makes you scratch your head trying to justify this while climate change is encouraging people to eat bugs.


> Rather than high speed rail to get the masses into cities for work

That wouldn't really work outside of some very specific cases. High speed rail (300km/h+) needs some distance to get to its cruising speed. Below that it's a waste of money. The shortest high-speed rail route i know of is Paris-Reims and it takes 40 minutes, which is decent for a commute, depending on home/work to train station distance.


Those specific cases cover massive numbers of people so why aren’t they being done? I don’t expect HSR everywhere but in the dense areas


But you need dense areas at specific distances for high speed rail to make sense for commuting.


How is the fuel efficiency of these? They go faster, but I assume they would also fly higher where the air is thinner. Does it cancel out?


For concorde the numbers are quite different. Stealing from truly epic concorde thread on pprune.

https://www.pprune.org/tech-log/423988-concorde-question.htm...

At the beginning of the take off roll, each engine would be burning around 21 tonnes/hour.

Anyway, back to some figues; at Mach 2, 50,000', the typical fuel burn per engine would be around 5 tonnes/hour, falling to around 4.2 tonnes/hour at 60,000'


Adding to the supersonic questions - how will they deal with the sonic booms? I assume they're still banned over land, which significantly adds to travel time?


As the press release says, it’s specifically designed to replace over water routes. There are many international routes (some domestic, like Hawaii) that this can handle. So it won’t be doing anything like LA->NY.


They will deal with the sonic booms the same way that Condorde did: by flying over water.


I wonder how noisy they are even sub-sonic. Concorde was so loud on takeoff and approach, you'd stop and look up even living ~20 miles away from Heathrow. If you tried to introduce that now, there's no way would it be accepted.


Old jet engines are super noisy. Modern jet engines are much much quieter.


Plus a significant impact of Concorde was the (very turbulent) flow from the reheat; from memory it's not really dissimilar to many modern military aircraft with reheat today.

They'll get a fair gain from just not having reheat, yet alone the rest of the benefit of decades of aerodynamic design around engine exhaust flows.


Reheat = Afterburner, for any USAsians reading: https://en.wikipedia.org/wiki/Afterburner

(I didn't know and had to look it up)


What makes the newer engines so much quieter?


They have larger fan blades, for one. That means they move a large volume of air relatively slowly, instead of a small volume of air moving quickly.

Consider the difference between a large shop fan, and a small high pressure compressed air nozzle commonly used in workshops for cleaning, with both sized to give the same "reaction force" (i.e. the same thrust). The high-pressure nozzle makes much more noise.


The metallurgy of the fan blades has also vastly improved.

Monocrystaline fan blades have very different material properties from the polycrystaline blades that (I am guessing) were used on Concorde.

https://www.americanscientist.org/article/each-blade-a-singl...


Thanks for sharing that link! It's amazing what people were able to come up with in the 60s, before computers and Wikipedia and 3D modeling... wow.

One of the patents mentioned is how VerSnyder was able to grow a turbine blade in a monodirectional crystalline structure: https://patents.google.com/patent/US3260505?oq=versnyder+196... just using a special mold and a specific alloy. That would later form the turbine blades of the SR-71 Blackbird.


I just reread it. All of it was familiar, but I had forgotten a few of the details.

The first monodirectional blades were introduced to commercial jet engines in 1974, so Concorde definitely did not have this technology with the original engines.


The routes they mentioned in the press release (NYC-LHR, LAX-Hawaii) are almost entirely over water.


Since no engine for it exists yet, no one knows.


They agreed to purchase 20 aircraft, not the company itself. The title is a bit ambiguous.


Sorry, I had to reword and shorten the headline from the linked page to fit within HN's title length limit.


Quite misleading - not that you did it intentionally, but the title "reads" as AA acquires the company, not an order for 20 aircrafts.

Better title - and still within HN limits - would have been:

"American Airlines to buy 20 Overture aircraft from Boom Supersonic"


Thanks for clarifying I was confused why an airline was getting into the airliner business, this makes much more sense.


Yeah should say places order for boom aircraft


Agreed


Meaningless PR bullshit without knowing how much the down payment was.

Wouldnt be surprised if American put less than 1m down, which makes this nothing more than a slightly expensive PR campaign.


I'm reminded of all the airline announcements at the end of the 60s announcing agreed purchases of Concorde and Boeing 2707.


and guess what happened at that time too: capital suddenly got very expensive and companies went under.

this is the worst possible time for launch and the name will be quite poetic


From SNL: Start-up airline Boom Supersonic has announced it is going to fly passengers anywhere in the world in four hours or less for just a hundred dollars. So get ready to fly fast and cheap on the only airline named after the sound of an explosion.

On a personal note, this company is based out of Centennial Airport (KAPA) which is in my neighborhood


These planes are utterly pointless. The cost and experience will never be competitive with an overnight flight in business class, and the combination of the ongoing environmental crisis and the low efficiency make fuelling it practically impossible. Functionally equivalent to a Ponzi scheme.


Let us not forget that American is $36B in debt after a huge amount of borrowing to get it through COVID.


If Boom is able to come out with a new supersonic aircraft, is it possible for a startup to compete with Boeing or Airbus in subsonic aircraft? Either coming up with a new design or another innovation that can compete. Or, are those companies pretty much set with impassable moats?


Unless Boeing or Airbus screw up financially, which is almost impossible, the duopoly is set in stone. It will take massive government backing to change that, Airbus itself is proof of that. The only parties that do challenge the big two on single aile jets are Bombardier and Embraer, one of which was bought by Airbus and one which was almost bought by Boeing.


Right.

At this point a new aircraft program is easily $15B+ of development. That kind of money is hard to come by for a new aviation company.

China, Russia, and Japan have all tried breaking into the market as well without much success.


Why aren't the Chinese and Russians successful at building airliners? International politics aside, they have workable products, so why can't they break into the duopoly.


Duopoly markets can be surprisingly efficient in some circumstances, so it may not be profitable for other firms to enter the market.

https://inomics.com/terms/bertrand-competition-1504578


There is an excellent book on this subject: https://www.amazon.com/China-Airborne-James-Fallows/dp/14000...


> they have workable products

Not so, not for Russia anyway:

https://en.m.wikipedia.org/wiki/Sukhoi_Superjet_100


And that was a very promising program.


Workable != competitive, and in an industry as cutthroat in aviation airlines want the absolute best in fuel efficiency and reliability to undercut their competitors by $5.

There are other commercial aircraft manufacturers but essentially in each size segment you will only see two players. Embraer doesn‘t make any direct competitors with Airbus or Boeing, as an example.


Embraer jets got rebranded as A220s not that long ago, great planes that took over the market that served by short 737s and A319/18s. No competition for the bigger planes, that is true.


The A220s were Bombardier.

Them selling out to Airbus had more to do with general issues at the parent conglomerate (they also exited trains and snowmobiles to raise cash). But they still make corporate jets.


Ha, I always mix up Bombardier, Embraer, Boeing and Airbus when it comes to whom bought whom. And yes, Bombardier always made great aircraft. Embraer as well, by the way.


I disagree. The disruption can happen as many routes transition to electric. Boeing and Airbus might wait for to long.

There are already new companies doing short-distance electric passenger flight. These companies could well scale to longer distance flights.

You could also imagine a company like Tesla getting in that business as well.


There are no electric jet operated commercially, and wont be until at least 2026. And those that are in development are meant for distances around 100-200 km or strait up urban mobility. The latter of which falls squarely into the helicopter segment.

And as far as automotive, or generally non-aerospace, companies are concerned, well, aerospace is hard. Really hard, it is with the potential exception of life science the most regulated industry on earth. None of the automotive experience (close to none, but you get the point) translate into an aerospace environment. And even if, we are still looking at billions of development cost for small aircraft to be used commercialy, in the range of ten billion plus for commercial airliners.


> There are no electric jet operated commercially, and wont be until at least 2026.

Yeah, I wasn't making any time prediction, but big technology changes can break established industry patterns.

> The latter of which falls squarely into the helicopter segment.

There are lots of markets in the past that flew these kind of routes and with electric other can again and more routes can be added because of the changed economics. Helicopters are unsafe and have low capacity, I don't really think they are actually competing in the same space.

They address something different then something like the Heart Aerospace ES-19. That plane is 400km, 19 seater designed to launch in 2026.

And that is with incredibly conservative choices, conservative air-frame, conservative batteries and so on.

There is a huge amount of potential for increasing the range left once you fully optimize every aspect of the plane around electric.

> And as far as automotive, or generally non-aerospace, companies are concerned, well, aerospace is hard.

I picked Tesla for a reason. Tesla works with SpaceX. Those two companies already work together on many fronts. Tesla battery packs and electric motors in SpaceX vehicles. They have shared research divisions in material science and likely other things. Musk has been talking about electric plans for decades, its pretty clear that he wants to develop them and has mentioned before that between Tesla and SpaceX he has the ingredients. Its just that there is so much more scaling to do in automotive and trucking that it doesn't yet make sense to invest the resources.

Lets just be real, Tesla knows much more about electric motors and batteries then companies like Heart Aerospace, or existing companies like Boeing/Airbus. Yes the industry is regulated more and certifications are more strict, but a company that produces 3+ million electric motors a year (more large electric motors then anybody else in the world) fully vertically integrated, can manage to match companies like Heart or Airbus when developing battery packs and electric motors and get them certified and produced.

SpaceX speaks for itself, they outperform Boeing to an almost embracing degree in space, see Crew Dragon compared to Starliner. I am confident that if they were to work on an airplane they could do it. They had to do a huge amount of certification work for DoD, for NASA, they know how to work with regulators and the get hardware certified.

Now of course, it would not be easy and success in aerospace is never guaranteed. But the ingredients are there and the is little question they could raise the required funding. I think that would be a better thing to focus on then robots to be honest.


I think there is some questions of them being able to scale up the production.

But Boeing and Airbus aren't invisible if you are offering a product they don't sell. See A220 with somewhere 220+ units sold. It did end up in hands of Airbus, but it was effort by Bombardier.


No. There is no way they can compete with say Airbus's quality and build quality. If they think people are gonna trust their lives to a startup company kept afloat by current interest rates over Airbus, I got a bridge to sell you.

If supersonic travel was in demand post-pandemic and rising inflation, interest rates, Airbus would've been all over it.


Eh, the aircraft manufacturers fuck up market projection too.

Boeing has almost entirely ceded replacement of its own 757 and 767 to Airbus since it offers nothing in that midsize range today. Airbus fucked up thinking that the A380 was going to make money, and it took them a while to get the A350 right despite pressure from airlines to actually compete with the B787.


To everyone saying this will not work because it's more expensive... jets were more expensive than turboprops. And even though the former use more fuel, we prefer them.

The costs of flying an airplane isn't proportional to its fuel usage. The faster an aircraft is, the more flights it can perform per day.

The carbon emissions impact of flying a gas-guzzling supersonic aircraft aren't evident either. Of course, more gas is used per trip but fewer planes need to be manufactured. Since there is no supersonic business jet, it could also make sense for some people who used to fly private for the speed and convenience to reconsider as they may get faster to their destination by flying supersonic.


> The costs of flying an airplane isn't proportional to its fuel usage. The faster an aircraft is, the more flights it can perform per day.

It is indeed not proportional, but not in the way you are thinking. Drag (and ~fuel consumption) scales with velocity squared, so a plane flying twice at fast (and neglecting any time at the airport, which would make the argument even worse) would use four times as much fuel. I.e., even if twice the amount of passengers would be served, it would be done for four times the fuel consumption and four times the carbon emissions (or twice the fuel consumption per trip).


That doesn't have much to do with the point I'm making. I'm saying if you double fuel usage, you don't double the cost of using the plane.

As cost of fuel is only a percentage of the price of the ticket, it's pretty obvious that there is a threshold as a percentage of total ticket cost under which spending 4x more in fuel to fly say 1.5x more passengers (because the airplane isn't flying 24/7) makes business sense.

That is obviously one of the reasons why they are starting with business class tickets because, fuel consists of a smaller percentage of ticket cost.


Yeah, there is an epsilon on top of fuel. But maybe you missed the obvious fact that all aircraft are getting slower rather than faster over the last decades, so that threshold is in the opposite direction of what you're proposing.

And there is zero logic behind your second obviousm, as your premise is already wrong. The reason they start with business class is because you can charge more per seat. Seems pretty obvious.


Fuel cost, depending on routes, number of business seats, seat occupancy is at about 25% of total costs [0]. 75% is what you call epsilon? Aircraft speed as barely budged since we transitioned from turboprop to jets. That's something you could call epsilon.

You're right that they start with business seats because they cost more. Business class seats cost 3-4x time economy while occupying less than 2x the space so the cost of fuel as a percentage of the ticket price is lower. It might not be obvious to you but I'm happy to explain it :)

[0] https://www.mckinsey.com/industries/travel-logistics-and-inf...


> 2x the space so the cost of fuel as a percentage of the ticket price is lower. It might not be obvious to you but I'm happy to explain it :)

See, your claim is that fuel cost is the sole reason they do this. I'd argue it's obvious they'd do that even if all fuel was free.

> Aircraft speed as barely budged since we transitioned from turboprop to jets.

Ah, it's again one of those nonlinearities you seem to have trouble with. See, the cost increase is, again, not proportional to speed. On top of the quadratic scaling, you have a very nonlinear and steep (not-proportional!) increase in drag coefficient. So, when you look up that what I say is true, but you want to weasel your way out by saying 'it's not by much', you're missing that the impact on drag (and fuel) is substantial.


And fuel cost is typically more than double the capital cost in an airline's budget at subsonic speeds

And the proposed aircraft are less than half the size of the aircraft they'd most likely replace, so actually sell fewer tickets on double the flight numbers


> a plane flying twice at fast would use four times as much fuel

Not that this only applies if they fly at the same altitude. If you fly higher you can avoid that. That of course causes other problems but it is a relevant factor.


The fuel burned by an aircraft is almost certainly the dominant portion of its lifecycle carbon emissions. I expect the carbon emissions due to its manufacture are negligible by comparison. Have you seen a source either way?


You're right.


From Boom's Wikipedia page, they seem to have built zero airplanes which even attempted to take off. That includes their 1/3 scale "technology demonstrator" test plane - which was supposed to fly back in 2017.

I'll guess that American's "non-refundable deposit" for the first 20 Boom aircraft was pretty small, and came out of American's marketing budget. Or was a negotiating tactic, to help American get a better price from some real aircraft manufacturer.


On the heels of a news headline saying they’ve cancelled another 30,000 flights through November, I’d bet you’re on to something.

https://www.consumeraffairs.com/news/american-airlines-to-cu...


This is good news for Greensboro, NC and the NC Triad region. The Boom manufacturing/assembly will be done there (at least partially). HondaJet already manufactures there, and there are a number of other aerospace manufacturers in the area. (A lot of embedded and mixed-signal too.)

I live in a neighboring town not far from the boutique Triad Semiconductor, which designs digital/analog chips and components for many applications, including space.


I'm surprised by this... I'd imagine that all of the BS we've added to airport procedures (under the guises of "security", mostly), would sort of help negate the typical "Concorde" case. In a universe where you still need to show up umpteen hours early for check-in, baggage, security, does having a plane that may cut a fraction of the time of the trip really seem compelling?


Getting from curb-to-gate today is easier and faster than it was pre-9/11.

That's just domestic. For international travel it has been a literal exponential decrease in hassle.

Of course, this all depends on whether or not the airport you use (and it is 100% dependent on the airport itself) has deployed all of the automated systems being used to lower terminal transit times.


Seems more alluring as a private jet.


THAT would make tons of sense to me... here the flight is a greater share of the overall flight time, so cutting into that yields a greater percentage reduction on overall travel time, which is presumably the variable you'd want to most affect.


I wonder what Elon thinks about this. There was one demo from SpaceX about using their rockets for Trips where they can lower down transatlantic flights to 20 30 mins (if you have strong sto-mach) Or Boring Company focused to hyperloops.

My humble opinion is that it's aviation company without huge innovation or disruption of the industry. More like a fast horse rather than car.


Curious how the combination of remote work, videoconferencing, and the really luxurious business class / first class on sub-mach aircraft will compare to this.

This is slower and smaller than concorde, so we'll see if the market really values speed over convenience / luxury. Boeing made the opposite decision 20 years ago when they cancelled the sonic cruiser.


There is no substitute for F2F for some types of work. Everyone I know hates flying, even if it is lie-flat. If someone can reduce the pain of flying to UK/Europe and Asia by knocking a few hours off then I would definitely prefer it.


Timezone differences alone make F2F worthwhile, even if you're fully remote. A week here and there face-to-face on the same clock is valuable.


how? jetlagged meetings aren't known for their mental clarity


I'm pretty sure a Europe-Australia line that doesn't take two days with 3 layovers would sell like hotcakes regardless of accommodations.


If you haven't seen it -- Qantas are pushing ahead with "Project Sunrise" on A350-1000. So you'd get to MEL or SYD without a layover - but with something like a 20 hour flight.

https://www.qantasnewsroom.com.au/media-releases/qantas-anno...


The Boom Overture lacks the range for the Europe-Australia line. It would have to make two refueling stops to fly CDG to SYD. I think the primary initial market will be Transatlantic.


If they can find a way to add another ~400 nautical miles, you could do hawaii.


If their specifications are accurate, they will be able to fly California to Hawaii with an adequate fuel reserve. So there may be a market for a few supersonic aircraft in that market, but fewer than the Transatlantic routes.


Qantas is already flying Perth-London direct (17 hours), and is seriously exploring options for pulling off Sydney-London direct.


I dont think supersonic will be a success. Remote has made business travel a lot less necessary and more predictable, so people are more likely to plan multi-hop business tours rather than flash transatlantic and transpacific flights. The failure of A380 is also telling: people are fine with flexible hops. But most of all people want to reduce their carbon footprint by minimizing travel distances, not travel times.


So we can kind of rough it out - improving speed will make fuel costs go up (but how much?) but other fixed costs will go down (pilot time, airframe time, etc).

However you may also be stuck where the people who will pay for the faster time are the types who will NOT sit in cattle class, so your airplane will have to mainly be first-class/business style seating.


As I understand it, Concorde was closer to coach in terms of seats and leg room than modern business (though with service that matched the price tag) so I can't imagine any issues here. If you could fly New York to London in less time than it takes to go from New York to California, while being served well, I can't see that being too much of an issue.


Why would you assume this aircraft wouldn't have a luxurious cabin? It looks pretty nice from the one rendering they have on the site. 1-1 seating, so direct aisle access for all. Plenty of room.


Renders of any new aircraft always show them full of bars, gyms, bowling alleys etc, but the reality is just as many seats crammed in as they can fit, and then some.


They are targeting business class passengers, which makes sense. Supersonic is not going to make the profits off the Ryanair set.


As someone who has actually flown on the Concorde, I can say that I'd gladly endure its tight seats again and empty my wallet in exchange for a shorter flight. Heck, if I had the option between spending $20,000 for a NY-London roundtrip on an Overture (the same price for that route on the Concorde, inflation-adjusted) versus spending $20,000 to charter a long-range private jet (likely a significant underestimate), I'd go for the Overture in most cases.

However, although I'm rooting for any company that's making a sincere (as opposed to fraudulent) attempt at bringing back supersonic travel, the hardest challenges may still be ahead for Boom. The biggest one is the need to find or build a new engine. They've recently redesigned the Overture to use four engines instead of two, which should ease required engine specs, but there's no engine that would meet the reliability, noise, fuel consumption, and dimension requirements for a supersonic passenger aircraft.

Related to the engines: money. It sounds impressive that boom raised at least $150 million, including $60 million from the US Air Force (which has the added advantage of creating a new customer segment in the military)... until you learn engine development alone would require in the ballpark of $6 BILLION of capital. Aviation history is rife with examples of amazing, innovative aircraft designs that failed because no suitable engine was available.

Also, Boom leadership has set some ambitious goals, which makes me a bit skeptical. They plan on using sustainable aviation fuel (SAF). Great! But now they not only need to create a new engine, they need to create a new engine that runs off of a new fuel. Additionally, they've set a goal price of $5,000 for a New York to London roundtrip whereas Concorde would've cost $20,000 for the same route. Heck, I once paid $8,000 for a Boston to Tokyo roundtrip business class flight. Nothing wrong with setting such a goal (and Boom isn't even the party that sets route prices) and it's OK for marketing claims to be a tad optimistic, but this tests the limits of credibility.

Lastly, there's the issue of possible routes, which is primarily limited by noise constraints. Unlike the Concorde, which needed afterburners to produce sufficient thrust for takeoff, Boom is going for a no-afterburner design. While this should expand the number of airports the Overture can use since afterburners won’t be blasting the neighborhood, you’re still not going to be able to fly over land. Boom suggest 500 routes are supersonically viable[1], which I’d assume means “pairs of international airports separated mostly by water”. We might be talking about something like 50 actual airports. only a fraction of those routes are not just supersonically viable, but economically viable. Of course, commercial aircraft are designed for particular types of routes. An Embraer ERJ-145 regional jet and the Boeing 787 long-range wide-body jet fly different routes. I’m not expert on this though; maybe 500 routes is plenty for a “total addressable market” in the aviation industry,

To bring it all together: my big issues with Boom are, one, engine development and, two, the choice of “hard problems” they decided to take on (specifically, SAF & cheap tickets). My hopes are that the engines are in development, using SAF instead of conventional fuel isn’t a big deal if you design for from the start, and the $5,000 thing is more about saying how low, hypothetically, an airline could price tickets while making money. I’d also like to know what the current status of the state-of-the-art is in quiet supersonic flight. NASA’s quiet supersonic demonstrator, the Lockheed Martin X-59 QuSST, combined with regulators’ desire to decide on supersonic overland travel in 2028, would open up new routes like JFK-LAX for planes meeting noise requirements, should regulators decide to allow it.

My hypothesis on Boom’s design choices? Quiet supersonic cruise is still technically challenging and has an uncertain regulatory future, and the political tide may be turning towards greater regulation on fossil fuels. So, by using SAF, Boom ensures that their plan will at least fly in an uncertain regulatory future, even if there’s no overland flight. And, using what they learned developing the Overture, they’ll be in a position to develop a quiet supersonic transport should regulators give the green light.

[1] I’d interpret routes to be something like airport-pairs, as in Laguardia-Heathrow would be one route. If you Boom could fly from three airports in the US to or from three airports in Europe, you’d have nine routes (3*3). This article talks a bit about the lack of clarity with Boom’s “route” number: <https://leehamnews.com/2021/06/04/hotr-500-destinations-for-...>


To the marketers at Boom, what a terrible name choice for an air plane company fellows.


And how does it align with agenda 2030 and the goal to reduce carbon emissions?


Aviation makes up a rather small portion of transportation emissions. I don’t think there is much point in focusing on clean air travel when cars and trucks produce such a massive amount of carbon emissions in comparison.

https://www.epa.gov/greenvehicles/fast-facts-transportation-...


I wonder if a transatlantic hop on this, with electric flight on either end can work to replace direct transatlantic flights while being faster and greener? Probably all depends on the switchovers.


This will be hardly greener than taking a regular aircraft.


It depends really. About half the GHG impact of flights is non carbon.

Is this better or worse on that account? I have no idea. But it potentially could be substantially different either way.


Boom is quite the name for such a speculative business. What's next, Bubble Airships Inc? (Luxury cruises, the slow route). They could also have a side business in submarine expeditions.


I thought it was a reference to the supersonic boom, although supposedly their planes will not have that loud noise. But as an airplane name it's very bad, nobody wants to go boom boom


I'll offer Iceberg Cruise Ships Inc. free of charge.


If TSA is abolished or scaled down significantly then this plane is dead on arrival.

7hrs London to NYC are more than acceptable, too bad it ends up being 10hrs


It already is if you fly business class. I’ve done drop off to gate <10 minutes at LAX & SEA multiple times.


Dude we get it, you ballin /s


Just in time for the newest wave of de-globalization. I’m betting against this , even if it’s sound on other fronts.


is the contract public? i would like to see what contingency is in place if Boom fails to deliver. Or more to the point, is this more PR to make AA appear to be forward looking, and bolster Boom's reputation with a deal that will never come to fruition. It's a win-win for investors


"agreement to purchase up to 20"

So, possibly zero. OK, thanks for the update.


Recently I've read an article about plane leasing, and it left me realizing that air-companies lease planes from such companies (one of biggest ones are Ireland) rather than buying them.

https://www.cnbc.com/2022/03/28/irish-lessors-have-terminate...

"Aircraft Leasing Ireland (ALI), members of which include SMBC Aviation Capital, Avolon, Aircastle and AerCap Holdings, which is the world’s biggest aircraft leasing company, said that all of its members have complied fully with the sanctions."


> American has paid a non-refundable deposit on the initial 20 aircraft.

Pretty glad I don't own American stock right now, because they're apparently led by madmen.


It's phrased in such a way to give the idea that they've made a significant commitment, but it's entirely possible it was something like a 1% down payment.


This is almost certainly how it was done - and even the "fully refundable" deposits airlines make with Boeing, et al are going to have "fixed non-refundable costs" even just to handle the paperwork.


Right. If you're going to place a deposit for aircraft with a startup airplane manufacturer, "refundable" only makes sense if you're willing to take warrants or something that will grant you IP when the company folds. If Boom doesn't deliver the aircraft, the company folds and goes bankrupt, it's not like the deposit funds are just held in escrow. Might as well make it "nonrefundable" to get the PR value.


The free publicity alone will pay for that.


"Non-refundable deposit" could be $1. In exchange they get their name mentioned in a load of press as being associated with new technology etc., so massively worth it for them. Also worth it for Boom as having "orders" from credible airlines makes them look more credible.


I can't roll my eyes enough.


"We are beginning our ascent, and thank you for flying BOOM!,"


It's the manufacturer's name, not the airline. No one says "Thank you for flying Airbus". They would still say "Thank you for flying American Airlines".


It's better than saying "AA". I was going someplace on the double-A highway and needed directions, so I plugged it into Google Maps and got to hear about the "AAAAAHHH!!!!!" Highway the entire time.


IMHO a better title would have been:

"American Airlines to buy 20 Overture aircraft from Boom Supersonic"

When reading the original title, I had the impression that the company was going to be acquired by AA.

Instead, it's "just" an order of 20 aircrafts.

Note that this is not a new move by Boom, they played this card when raising money when they pitched at YC demo day, and they're doing it again. The problem I have with this is the following:

> agreement to purchase up to 20 Overture aircraft, with an option for an additional 40. American has paid a non-refundable deposit on the initial 20 aircraft

It's "up to 20", and not "20", and there is a non-disclosed non-refundable deposit. If it's a, say, $10,000 per aircraft, total of $200,000 (ouch, should I say... up to $200,000?), it's a just a cheaper ad for AA, and ammo for the CEO when the board asks "where are you innovating?".

Good luck to Boom, but I am unconvinced this is a viable company and a viable business.


I thought the same.

But, it's an interesting thought, and in line with a very interesting thread that kragen brought to my attention: https://news.ycombinator.com/item?id=32009925

FedEx likes to buy out Boeing facilities so that they're not "completely reliant" on Boeing for anything, see https://www.ch-aviation.com/portal/news/102874-fedex-to-take... "Air cargo carrier FedEx Express (FX, Memphis Int'l) is to take over the lease of Boeing's Dreamlifter Operations Centre at Paine Field, Everett, quashing any hopes of a return of the B787 Dreamliner production to Washington State."

I wonder why more airlines don't choose to do similar things.


Yes these are "non-binding" commitments that are just marketing. Very deceptive but standard practice in aerospace. For example only a fraction of the Concordes that were committed in this way were actually purchased.

Until the plane is actually flying in the air you should just treat any announcements as misleading (they announced that their test airframe was ready, what, 3-4 years ago?).


It's not really deceptive, it's just that many people have a poor understanding of the accounting difference between LOIs, contractual bookings, and recognized revenue. These LOIs would not appear on an income statement, balance sheet or P&L... and no one ever suggested otherwise. It's just one signal (of many) that indicate market demand for high-capex products with long lead times.


> When reading the original title, I had the impression that the company was going to be acquired by AA.

Same... at least they should put an S to aircraft... but then again maybe they hit the strict character limit...


The plural of aircraft is still "aircraft".


Putting "up to 20" in the title would work.


Could go with "airplanes" which has a more conventional plural form and is much simpler and clearer in cases like this where we know full well what specific type of aircraft we're talking about.


Or aeroplanes!


sometimes I don't get English...


It's an artefact of where English gets the word "craft" from. In general in English the plural of uncountable things is the same as the singular. For example, the plural of sugar is sugar (sugars in English implies a group of different types of sugar). The word craft comes to English from Germanic (kraft). The meanings of these two words (English craft vs German kraft) diverged over time. In English the word has a meaning similar to that which is made or the manner in which it is made. Whereas in German it means the means by which something is made (i.e. power, in both the physics and non-physics sense). For example Kraftwerk in German means power station.

Since the "means by which" is uncountable (craft) then the plural should be the same as the singular; i.e. one craft, many craft. This also applies in English to older agglutinates like aircraft. Newer agglutinates (for example laptop) are far less likely to follow this rule; one laptop, many laptops.

English, due to its muddled heritage and well intentioned but half informed linguists over the years, is a very messy language.


I wonder how the craft word was adapted to mean the boat object.

I think for river travel it was common to build a boat/raft to make a journey and then break it up at the destination. In that context maybe the object of the boat was secondary to the act of making the boat. And at some point boats became more personified and thought of as things in their own right.


A couple other suggestions, although still not certain:

> Use for "small boat" is first recorded 1670s, probably from a phrase similar to "vessels of small craft" and referring either to the trade they did or the seamanship they required, or perhaps it preserves the word in its original sense of "power."

https://www.etymonline.com/word/craft?ref=etymonline_crossre...

I'd never even though about this, so thanks for that.


I suspect it was a shortening of watercraft. According to wiktionary the use of the word for water vessels was originally used for smaller loading craft. So using the older Germanic meaning of "by means of", the phrase "it got here by watercraft" could be translated as "it got here by means of water". One could assume that it wouldn't take much for the word to go from preposition to noun; especially in the context of agglutinates and abbreviations.

The English word "boat" comes directly from German; "das Boot".


The grammar is easier then German


Same here, regarding the misperception of Boom being acquired by AA


Totally agree about the wording of the title comment and other commenters in this thread.

But "Boom Supersonic is transforming air travel with Overture, the world’s fastest airliner, optimized for speed, safety, and sustainability. Serving both civil and government markets, Overture will fly at twice the speed of today’s airliners and is designed to run on 100% sustainable aviation fuel (SAF). Overture’s order book, including purchases and options from American Airlines, United Airlines, and Japan Airlines stands at 130 aircraft. Boom is working with Northrop Grumman for government and defense applications of Overture. Suppliers and partners collaborating with Boom on the Overture program include Collins Aerospace, Eaton, Safran Landing Systems, Rolls-Royce, the United States Air Force, American Express, Climeworks, and AWS."

This^ is significant support they already have. So they could operate for 10+ years, which seems like they will (even if they are just in R&D and burning cash). In a way, it is viable to the employees and suppliers, if they get paid for such a long time haha.


The deposit could be $1 for all we know and fully cancelable with no commitment to buy or deploy. The press release is basically fluff.


It says non-refundable. But agree it could be as low as a buck.


> Good luck to Boom, but I am unconvinced this is a viable company and a viable business.

Same. I think their timelines are too aggressive. I want to be proved wrong though!


this is wild


Burning more Jet-A to get less people around the world faster has got to be the most tone deaf idea this decade. I'm a pilot, I just attended Airventure, and I love the history around SR-71, Concorde and the other incredible high speed planes we've built. But this is an idea that had its time and aviation has moved on to high bypass turbofan engines, reliability, safety, fuel efficiency and reducing our environmental impact.

There is so much opportunity for innovation in areas of aviation where we desperately need to innovate: Getting rid leaded avgas, moving away from fossil fuels altogether which includes fields like energy storage and electric propulsion, developing an efficient trainer to replace the piston lead-gasoline burning C172 that is so ubiquitous and makes up much of the 1500 required hours for an ATP license. So many opportunities.

Aviation is ripe for innovation. This ain't it.


Just want to reply to my own post here to add that most people don't realize that the Cirrus SR22 is the world's best selling single engine piston aircraft and has been for the past 20 years. And it's wholly owned by the Chinese government. I'm aware this is a different market, but I want to illustrate how we're losing our lead in some critical areas, while we focus on creating solutions looking for a problem.

Incidentally, Boom is 5 minutes from my office here in Centennial, Colorado and where I fly out of KAPA. I'd like to see innovative US aerospace companies succeed, but I feel like these guys are chasing the wrong idea.


> I want to illustrate how we're losing our lead in some critical areas

How is single-engine piston aircraft a critical area?

edit: I do note that according to 2019 report, North American companies had >60% global marketshare in both turboprops and business jets in terms of units shipped


> How is single-engine piston aircraft a critical area?

Where do you think airline pilots come from? New pilots learn to fly in single-engine piston planes. And then again as flight instructors and commercial (non-ATP) pilots while building time to get their ATP rating and move onto the airlines. The continual slow death of GA is only going to worse an increasingly dire pilot shortage.


The pilot shortage (if there really is one) is almost entirely the fault of short-sighted airlines and their unions; it has little to do with GA manufacturers. If airlines really wanted a larger supply of ATP ratings then they could simply hire pilot candidates with little or no flight time, then pay them to go through training. Some large foreign airlines already recruit pilots this way.


I did not say the shortage was created by GA manufacturers, I said that GA in general is the start of the career progression for airline pilots in the US hence it serves a critical function for society. I too thought the pilot shortage was a myth until this past summer when it became abundantly clear there were not enough pilots in the world to deal with the resurgence of travel.

You could also argue that US pilots have superior training due to their GA experience as well. The over-reliance on automation and lack of stick and rudder skills is becoming a liability in those foreign airlines that train pilots exclusively in simulators and then throw them into the right seat of airliners where they're essentially computer operators instead of pilots.

The inability to for an airline pilot to land without autopilot is a very real thing: https://metro.co.uk/2019/05/16/russian-jet-crashed-captain-c...

Or the ability to fly in IMC conditions without an autopilot: https://www.flightglobal.com/safety/experienced-crew-struggl...


Those are separate issues. Even if airlines pay for pilot training, they could still have most of the syllabus done in actual airplanes rather than simulators. The FAA generally only allows up to 100 hours of simulator time to count towards ATP requirements. The major airlines are large enough that they could just buy their own trainer aircraft.


So you're right back to flying single engine pistons then. I don't understand the point here.


1500 hours per ATP certified pilot.


TIL Cirrus was owned by CAIGA - looks like they're also building some light bizjets for Cessna...

Neat. Love to watch traffic at KAPA - saw a Walton plane land there the other day an hour or so before Condi was named part owner of the Broncos.


Third busiest regional in the nation. Super fun to fly in and out of and tower and ground do a spectacular job!


This isn't going to be applicable to 95+% of aviation, but for something like a flight between the US and Australia, e.g. LAX to SYD?

Going from a 15h to 8h flight will be huge -- that's 30h to 15h round-trip.

I'm American and visited Australia once, and realized I probably never would again, it's just too far. An Australian friend of mine here in the US only went home to see his family every few years. It just takes sooo long, stuck in an economy-class seat.

Supersonic makes a lot of sense not as general-purpose, but for long-haul flights between hemispheres. At least until there's an economy-price "sleeper car" equivalent accomodation where you can actually sleep on flights.


The Boom Overture lacks the range to fly non-stop LAX to SYD. It would have to make at least two refueling stops (something like LAX-HNL-NAN-SYD), so it wouldn't save any time. The crew would also need to be changed at least once due to working time limits, and it's too small to accommodate crew rest facilities.

This airliner is primarily targeted at shorter Atlantic routes; if they succeed in that market then they might build a larger successor model with the range for Pacific routes.


You don't need to go everywhere, really. Especially not halfway round the world for a vacation.


The number of reasons people want to move around the worl are almost innumerable. Just because you don’t value it doesn’t mean others can’t.


The reason for op was getting to his vacation place faster, so I guess we were discussing 1 reason.


This reasoning can be used to also say you don’t need to go anywhere outside of your living area.

Without removing freedom of mobility, the only way we have to mitigate environmental costs is through price pressures which could be used to fund net neutral technologies.


The difference between not traveling and a 15 hour flight is huge (especially if you have a family those 15 hours away). But the difference between 15 hour flight and 8 hour flight is marginal in that context. And this is compounded by the fact that there are some regions which are geographically closer then Australia, but take significantly longer to travel to because they lack the infrastructure for fast and convenient travel. So honestly 15 hours is not that bad.

Yes, strictly you don’t need to travel anywhere, but we should allow people to travel in the most economical way feasible. Supersonic jet travel is not that.

If 15 hours in an economy class is too much for you, but you can afford a supersonic flight ticket, perhaps you should consider upgrading to a business class. Or if you don’t like that, consider braking the flight up in 2 or 3 parts sleeping at a nice hotel in between. This is a much more climate friendly option then a supersonic flight that only saves a few hours of your time.


If you have everything you need in your living area then you don't need to go anywhere else, yeah. In most places you can get everything you need within a 200km radius of where you live, unless you have very particular needs.

I'm glad you considered all possible ways to mitigate the environmental costs of flying. Seems like wasteful supersonic jets aren't one of them?


I completely agree that right now, this is the right mindset. We need to reduce our footprints a lot until we are in better shape as a planet. However, I hope that one day we'll be able to travel as much as we want in a sustainable way. It is a great thing.


Would be cool, sure.


Agreed. Boom claims they will be "sustainable" because they are going to invent some kind of synthetic biofuel.

Wait, it looks like I either misremembered that claim, or they have backed away from it:

> "Overture’s fleet will be able to run on 100% sustainable aviation fuels."

https://boomsupersonic.com/sustainability

Color me skeptical. Making existing aviation more climate-friendly would be a much more worthy goal than this ridiculous supersonic vanity project.


Meanwhile, my data center has been fully prepared to run on electricity supplied from cold fusion reactors for years!


It's legit. Take a look at Prometheus Fuels. More details:

https://www.science.org/content/article/former-playwright-ai...


The world is a big place, it can handle 100 or so of these fluffing around.

And there actually may be realistic optimization scenarios.

People don't want to have sympathy for 'world leaders' for example, but often physical presence is an important thing. And they waste so much time.

I don't like my own PM but I'd rather they spent a little more to cut his travel time down; his time is extremely expensive.

And this sounds ridiculous at first glance: but even if he could literally get reasonable sleep more often. His decisions are so impactful, the leverage so much, it matters. And I don't even like the guy at all.

That aside the secondary advantages from it might be positive, we need R&D that's ahead of the curve.

I'm fine with this as long as everyone isn't flying it all the time.


Tone-deaf to many people who care about climate, sure. But what about to the executive types who believe they are so important that they need to be there in-person, and they get to expense these tickets to the corporate account? I think the same executives who are trying to kill work-from-home and have an inflated view of the benefits of in-person meetings will buy these tickets up.


In the GA segment, the Pipistrel Panthera is really interesting.

With the currently available conventional engine, it vastly outperforms the Cessnas and Cirruses, AFAICT.

So with the hybrid and pure electric options in development (these were planned from the start, so the plane is designed for them), it is still competitive.

https://www.pipistrel-aircraft.com/products/general-aviation...

(Not affiliated or associated in any way, just a fan of aviation innovation)


Pipistrel is now owned (as is Cessna) by Textron.


That was my first thought as well. We are in a climate emergency, and currently airlines are not paying for the damage they are systematically adding to the catastrophe. I don’t see a future where this just continues. Either we really mess up the climate with all the societal collapse that entails, or we make these polluters pay for their damage. In either case there is hardly a future for this “innovation”.


> Getting rid leaded avgas

I was shocked to hear that leaded gasoline is still around, so I did a quick search. Turns out most (all?) piston-engine driven airplanes still run on leaded gas. Jet airliners don't, so I'm not sure if the overall impact is significant, but nonetheless shocking to hear that we're still spraying lead into the air we breathe.


Yes, 100LL still has lead in it. And despite what it may seem based on skewed figures from those who want to see local airports closed so they can build more strip malls and condos, there has been a 99.99% reduction of lead pollution from gasoline overall since the phase out of automotive leaded gas. We're working on getting unleaded avgas, you can blame the FAA for it taking so darn long, but it's hardly an environmental emergency.

> Turns out most (all?) piston-engine driven airplanes still run on leaded gas

Not technically all. There is unleaded avgas although it's not yet common and some piston planes are diesel.


Some of the new piston planes I believe are rated to use unleaded but the problem has been legislation and the FAA regarding getting unleaded approved to make it legal and ubiquitous


The FAA has been dragging their feet on this issue for over 20 years now. At first the excuse was that there wasn't a viable alternative, but now there is and they are still slow rolling it. The administration has a almost pathological fear of change.


There's a flip side to reconsidering aviation--the choices we make as consumers. Since leaving the aircraft manufacturing industry over 20 years ago, I have flown on 3 flights at approximately 5000 miles total, all 3 of which I wish I could have avoided. I'm not saying everyone could live this way, or that I'm particularly environmentally responsible in general, but it is possible. My life during those 20 years was rewarding and interesting, for the record.

The pandemic was terrible for the most part, but it did give us an opportunity to rethink how we live and work, including how to lessen future pandemics and enviromental degradation with our choices on transportation.


Feels like there is a business case for people willing to pay to reduce trip times for trans continental flights.

The problem is that the greenhouse gas impact will be higher for a supersonic trip compared to a subsonic one. This is on top of the issue that we don't really have a good low carbon alternative for longer range air travel (batteries don't have anywhere near enough specific energy). The best option we have is synthetic jet fuel produced from green electricity. Producing jet fuel that way is many times more expensive than fossil fuel jet fuel.


It's not like tickets on these planes are going to be cheap anyway. You could double the fuel cost and I doubt that would double the ticket cost.


> to get less people around the world faster

What does “less people” mean? You mean Boom is targeting only the ultra-rich? That’s not their aim. They aim to make supersonic flight both possible and affordable.


According to their propaganda, they are going to make jet transport cheaper AND faster AND greener.

I see no evidence that this is at all realistic, and a lot of evidence to the contrary.

Do they even have a story explaining how their new supersonic jet could possibly reduce costs?


Hmm, yeah. I mean with modern technology it should be feasible to create a more cost-effective / greener supersonic airliner than Concorde.

But basic physics dictates that supersonic flight requires a lot of power, as well as low bypass turbofans. So competitive with modern "normal" airliners in terms of cost or emissions per seat-km, nope, not gonna happen.

Synthetic jet fuel is a good idea that deserves R&D money (if we're gonna keep flying long distance in a carbon constrained world I think something like that is going to be necessary), but is orthogonal to a supersonic airliner. Unsure why they think that bundling synthetic jet fuel (itself a high-risk R&D project) with their supersonic jet (another high risk R&D project) will do anything but increase the risk of failure of the entire project. Well, the uncharitable explanation why they're doing it is of course greenwashing.


Concorde had a cruising speed that was 2.31 times higher than Boeing 747, and a lift-to-drag ratio that was almost the same times lower (2.36). So, every second Concorde had to burn about 2.36 times more fuel per ton of aircraft compared to 747, but it reaches the destination 2.31 times faster. All in all, the fuel consumption during the cruising phase of the flight was comparable. Well, Concorde had a horrible fuel economy during takeoff, so overall it was pretty bad compared with the 747.

But 50 years have passed since the Concorde was designed. Both computational fluid dynamics algorithms and computing power have made tremendous progress. It's quite likely Ouverture will have a much better fuel economy than Concorde, if only for the fact that it will use turbofan rather than turbojet.


In theory, a faster airplane is more productive (fly passengers farther in the same amount of time). So crew and capex costs are lower per mile. Maybe a crew can fly New York-London and then fly back, vs a subsonic airliner with a crew that flies one way, stays a day for crew rest, then flies back.


Cheaper than the current options for transporting 80 people via supersonic aircraft.


No, they're explicitly targeting the business segment, basically replacing today's business class on traditional airliners with a similarly sized, similarly priced, faster alternative.


> Getting rid leaded avgas

Isn't that more chemical engineering? Boom sounds mostly mechanical.

> moving away from fossil fuels altogether which includes fields like energy storage and electric propulsion

Isn't this mostly battery tech? Seems like a stretch for these experts to be working on that.

> developing an efficient trainer to replace the piston lead-gasoline burning C172 that is so ubiquitous and makes up much of the 1500 required hours for an ATP license.

At least this sounds like something in their wheelhouse, but needless to say, there's no money in that.

Boom is developing a plane that has demand. Simple as that. Not everyone needs to try to save the world.


GP is criticizing a company just doing something for the money without concern for the environment, which is a very reasonable criticism.


The idea is to move princelings around the world faster than lesser princelings. So long as they have the money they will suck up status symbols like a supersonic private jet.




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