
XB-1's wings are officially closed out - howrude
https://blog.boomsupersonic.com/xb-1-s-wings-are-officially-closed-out-c9b53591252e
======
yazaddaruvala
The blog post is hyper focused on the wings and didn't make a lot of sense
without context. This link[1] was extremely useful to better understand what
Boom is doing and how far along they are.

[1]
[https://boomsupersonic.com/xb-1/build](https://boomsupersonic.com/xb-1/build)

~~~
everyone
omg that website is freakin' terrible!

~~~
aetherspawn
I thought the website was really cool.

But the first image really sucked. The other 30 images and animated constructs
were super cool, but the entire experience was wrecked by the first image that
you see, which looked like a jpg of a plane drawn in ms paint.

~~~
xiphias2
Probably you're not looking at it from a laptop with touchpad...it's really
hard to scroll, also it's really hard to use the keyboard.

I can imagine that with a tablet/mobile phone it's a nice experience.

~~~
aetherspawn
I was scrolling on a laptop with a mouse which worked really well.

------
mauvehaus
This is probably a dumb question, but if the wings are now closed forever, how
does one do maintenance or inspection of the mechanical flight control systems
composed of cables and pulleys? Is the expectation that the XB-1 is going to
be used in flight for far less than the design life of those mechanical
systems?

~~~
AWildC182
Aluminum aircraft go together more or less the same way. There will be some
inspection panels but the interesting stuff is already exposed, there's very
little reason to go inside the wings, particularly on a composite aircraft
where corrosion isn't a problem. If you really need to see something, use a
borescope.

~~~
bronson
What if a cable snaps or a pulley breaks?

~~~
tlamponi
You can see in the article that now no cables are in there during closing,
they are in extra canals/tubes which can be accessed later on, be it for
installing them in the first place or maintenance.

------
ricardobeat
This is quite scary for a non-engineer. You're telling me that this little
supersonic plane has the whole wing structure held together by a handful of
4mm thick metal struts, manually _glued_ to the wing surface, with wire
pulleys running on the inside :O

~~~
AWildC182
Building a plane in my garage. You'd be surprised how minimal yet how strong a
lot of these structures are. The vast majority of the material I use is
thinner than a credit card.

~~~
bacondude3
I want to hear more about building a plane in one's garage. Are you using a
kit? How hard is it? Cost? How will you transport it to an airport once it's
finished?

It sounds like it would be a great project.

Thanks.

~~~
AWildC182
Kit: Yes, in my case it's an RV-8 by
[https://www.vansaircraft.com/](https://www.vansaircraft.com/) they're
probably the biggest name in town by volume and they make mid-cost kits. There
are some more and less expensive options however.

Hard: I took a class from a licensed A&P mechanic and while not mandatory,
gave me a pretty good idea of what I'd be up against. It is extremely
challenging even with a kit however. Lots of learning, lots of redoing stuff
because of mistakes, many many hours.

Cost: whatever you want it to be really. You can do safe builds probably from
around 40-50k for something like a Sonex or Kitfox to several hundred thousand
for a Velocity twin or even something turbine powered.

Transport: most people build in their garage and leave the wings off then
stick it in a trailer or U-Haul to complete final assembly at a hangar. It's
mostly a non-issue.

------
trhway
i'm in no way qualified to give any praise/criticism, it just caught my
attention (from the linked post on their cockpit/fuselage bonding
[https://blog.boomsupersonic.com/20-hour-bonding-event-
speeds...](https://blog.boomsupersonic.com/20-hour-bonding-event-speeds-
xb-1-toward-first-flight-b50a682d924) )

"It’s the following morning and bonding appears to be successful, but it’s
essential to confirm that the bond lines are shaped correctly or “filleted.” A
member of the engineering team, who is certified in the process, begins non-
destructive tap testing to audibly listen for voids such as air bubbles within
the bond. With several decades experience, he knows what to listen for. Using
specialized tools, he taps all bond lines and listens for different and
unusual noises. He confirms that bonding is a success."

In general it seems that their main fabrication cost is labor, and it would
probably be very hard to scale for production. I wonder why wouldn't they
choose titanium - the price of material doesn't seem to matter here, and while
it is hard to work with than say steel, i'd think it is still more mass
production friendly than carbon fiber.

~~~
Justin_K
Yea, not very scientific. Seems like ultrasonic tests would be good here. I
think they do something similar to check welds on ships.

~~~
nickff
Ultrasound inspection is very common for multi-layer composite construction.
There are large machines which transmit the ultrasound through a water jet,
for use in mapping the characteristics of curved surfaces. This water jet
ultrasound non-destructive testing (NDT) is used in aerospace for carbon
laminates.

That said, 'tapping' is an acoustic inspection technique, and can get good
results.

I am not sure why they selected the manual option, but they probably have a
reason.

~~~
jandrese
They're probably having the guy hit it with a mallet and listen for voids
because they're a Mickey Mouse operation by aerospace standards. Plus this is
a model so if something does go catastrophically wrong it at least won't kill
anybody, probably.

~~~
NickNameNick
It's a demonstrator, not a model - It has space for 2 test pilots.

------
gr2020
Somewhat OT - but from their FAQ they say they're targeting a price of $200M
for the Overture. I'm certainly no expert, but this feels to some extent a
bargain given the capability. Capacity 55-75 passengers. A few data points for
comparison (all of these approximate of course, with multiple variants
available of each):

Airbus A220 - $90M

Airbus A320neo - $110M

Boeing 787 - $140M

Boeing 777 - $320M

Airbus A350 - $325M

Gulfstream G700 - $75M

All of these can of course carry more passengers (except the Gulfstream), but
assuming it's somewhat efficient from a fuel perspective, and assuming an
airline could sell ~60 business class seats on each leg, I'm optimistic for
them - cutting your trip time in half is certainly something to brag about.

For reference, as an example, a British Airways 787-9 used for transatlantic
routes seats 8 first, 42 business, 39 premium economy, and 127 economy.

~~~
fragmede
The data-point for the elephant in the room:

Aérospatiale/BAC Concorde - $169M 150 passengers. Cruising speed: Mach 2

The Concorde was a thing of beauty. Massively expensive to produce and run,
and fuel inefficient, it was a passenger airliner that could outrun fighter
jets. Fighter jets of that era could get to mach 2 using afterburner, but
that's _especially_ fuel inefficient so they could only keep up for 15 minutes
or so. The money that went into the program (which is estimated in the
neighborhood of $10.3 billion) was later recouped in the form of expertise
that went into building Airbus.

A lot of time has passed since 1965 when the Concorde was first produced, and
the improvements in technology (especially for materials) since, will
hopefully allow the economics to work out better this time around. But with
the rise of lie-flat seats and personal entertainment systems, flying business
class is "good enough" compared to the surcharge that flights on the Concorde
cost, so I'm cautiously optimistic.

Taking 3 hours instead of 6 is better, but still not low enough. Add getting
to/from the airport, and checking into the hotel and all that, you're still
out the better part of the day.

The really pie-in-the-sky way to travel is if a certain reusable rocket
company ran (exorbitantly expensive) passenger service. Moscow to New York in
30 mins, or Moscow to London in 15.

~~~
dmos62
<=3 hour flight time kind of sucks, because you're spending additional 1-2
hours at the departure airport and at least 30 minutes at the arrival airport.
Then there are the trips from and to airport which are often 1-2h. Then
there's scheduling slack, which translates to additional ~20% wait time. When
flight time is 3h, you're expecting to spend 7-12 hours. Usually closer to 12,
because you'd rather wait longer than run the risk of missing one of the
transports.

One of my great travel-related discoveries has been that if I can find a train
that takes even about the same amount of time, it will always be much more
pleasant and less energy-draining than air travel.

~~~
thomas
All so true. The actual flight time is a non issue for me given the hassle of
the airport. But I’m guessing this is for higher end travel, where skipping
lines is the norm.

~~~
credit_guy
I once had the opportunity to fly a business-only airplane. There was no line
skipping. There was a whole dedicated terminal for these airplanes. As soon as
you entered the terminal someone would welcome you like at some luxury resort.
The passport and ticket thing was a breeze, then they would guide you to the
lounge, if you were early. If you timed your trip accurately, I guess you
could find yourself from the terminal door to sitting in your comfy seat
within 15 minutes. Champagne glass on the tray in front of you, of course.

------
herval
A bit of a sidenote, but I’d feel a bit anxious traveling on an airplane made
by a company called “BOOM”. A bit like driving a “Crash Vehicles” car?

~~~
ksec
Having been following BOOM for years this thought never occur to me. I thought
BOOM was the sound coming out of the engine signalling ultra fast / super
sonic speed.

What is annoying is that Now you have mentioned it I cant get that "crashing"
thought out of head.

~~~
TheSpiceIsLife
The _boom_ in a sonic boom doesn’t come from the engines as such, but rather
caused by the object travelling faster than the speed or sound (in air).

See
[https://en.wikipedia.org/wiki/Sonic_boom](https://en.wikipedia.org/wiki/Sonic_boom)

~~~
Reason077
And that's also one of the big reasons that supersonic passenger aircraft have
failed in the past - restrictions against supersonic flight over land due to
the extreme noise. It seems strange to me that Boom would want to draw
attention to this in their brand name!

~~~
fcanesin
The whole premise of the startup is to build a silent supersonic airplane.
Building atop several years of existing research and experimental programs
around silent sonic boom.

~~~
Reason077
Sounds good. But might then a more appropriate name for the company be
"Shhhhh"?

------
iandanforth
The level of care and organization in this photo feels equivalent to what I
would expect for a ground robot prototype out of a startup. Can any aerospace
engineer comment on what they see? Does their setup inspire confidence?

~~~
starpilot
It looks normal. Our shop (assembly line building full aircraft from material
stock, 2 football fields long) was like that except most of the workers were
filipino or hispanic, wearing street clothes. When they filmed a TV commercial
there, they brought in actors wearing red jumpsuits to scurry around as
technicians. Because like you, that is what the public expects.

------
earthtourist
I like the idea of supersonic passenger jets existing again. I'm not sure I
really see the point though.

Would you rather fly in business class comfort for 8 hours or with less
comfort for 4 hours? Almost doesn't seem worth the expense and risk of going
supersonic.

I would be so much more excited about an airplane that was large enough that
economy class seating was as comfortable as business class seating is today.
That would be much more revolutionary.

I would also get excited about an airplane that was vastly safer than the
already-quite-safe airplanes we have.

An airplane with a fail-safe fuselage that can disconnect from the rest of the
plane, parachute to the ground and land (or float) safely. This could
potentially eliminate fire danger by jettisoning everything flammable (gas
filled wings, engines, cockpit, and whatever else).

The fact that flying is uncomfortable and still-too-scary to millions of
people are the biggest opportunities for innovation that I see.

Flying at 500+ MPH is already quite fast given the size of the planet.

~~~
rconti
So far this sounds more 'affordable' than 'business class comfort' which I
STILL cannot afford no matter how hard I try to justify it to myself.

There's gotta be a market for an all-business-class plane, since we know that
first/business subsidize coach, but nobody's doing it yet. The airlines want
to throw those business class seats out as perks to people spending corporate
dollars, not charge the end user what they actually cost, in which case "real
humans" could afford them.

~~~
goodcanadian
There are a handful of all business class routes. For example:
[https://www.britishairways.com/en-gb/information/travel-
clas...](https://www.britishairways.com/en-gb/information/travel-
classes/business/club-world-london-city)

~~~
rconti
Wow, cool! Of course, I tried to get more info on pricing and following the
booking link took me to a "Generic booking" page which, even flying into JFK
and out of LCY, didn't show me the option, but I'd be really curious if I
lived in NYC, for sure.

I've also had this issue with the "Premium Service" United flights between SFO
and NYC/BOS. It supposedly exists, but whenever I search, I can't filter on
those particular flights.

------
xvilka
There also exists a Boom rival - Spike Aerospace[1]. They successfully
completed and operated flight demonstrators (SX-1) and working on delivering a
production plane now.

[1] [https://www.spikeaerospace.com/](https://www.spikeaerospace.com/)

~~~
tim333
There's something a little sketchy seeming about Spike if you look at their
website. The Boom demonstrator in this article is a real, hopefully supersonic
aircraft with lots of photos etc, but Spike seem to have zero photos of the
SX-1 which is/was apparently a subsonic radio controlled aircraft.

~~~
NotSammyHagar
How can spike say on their front page "The Spike S-512 is the only supersonic
jet in development that will fly at twice the speed of other jets without
creating a loud sonic boom." Boom is also aiming for 2x existing jets without
sonic booms. That's wrong, misleading, is there some narrow explanation for
how that could be accurate?

------
tqi
This test plane has a range of 1k nautical miles but a cruising speed of Mach
2.2, which works out to like 40 minutes of flight time at max speed? That
seems like a really tight window for takeoff + test + land + any kind of
safety buffer. I'd be curious to know how they handle those logistics.

~~~
elil17
They have a safety reserve of fuel. They fly it in the desert so they can
glide to a landing anywhere. And plenty of your time will be below max speed
(since air resistance is non-linear, your fuel consumption is much lower
during these times).

------
jamestimmins
Does this mean if any repairs are needed they'll have to rebuild the wing from
scratch?

I'd love to hear from someone at Boom what the main goals are for this
aircraft. And how it will differ from the larger transport craft they're
planning. Beyond size and capacity.

~~~
loeg
The company's goal is overland supersonic flight. Profitably, ideally. To make
that even a legal possibility means demonstrating they can be somewhat quieter
than prior supersonic aircraft. This aircraft is a proof-of-concept.

~~~
jamestimmins
Is it specifically to demonstrate that they can make a quiet aircraft then?

I think I'm curious specifically whether this is more about internal R&D and
building systems, or if it's meant to demonstrate they have the capability to
to create a performant supersonic aircraft, which they can take to potential
investors.

~~~
phire
This demonstrator is a 1/3 scale model of their final design.

It allows them to prove their exact final design will be quiet, along with
verifing the rest of the aerodynamics.

~~~
jamestimmins
Any idea how often the final design and the prototype don't match in terms of
volume and aerodynamics? I would have assumed that those parts are the easiest
to model with high confidence.

~~~
elil17
You don't need to build it to test volume and aerodynamics (math and wind-
tunnels can figure that out for you). This is probably more about finding
unknown flaws in the design/running down risk. Spending however much on a
prototype (10s or 100s of millions of dollars) just to marginally reduce the
risk that there's a fundamental flaw in your approach makes a lot of sense
when you plan to spend 6 billion total to develop the plane.

------
rebolek
XB-1? Is it named after Ikarie XB-1 from the classic Czechoslovak sci-fi?

[https://en.wikipedia.org/wiki/Voyage_to_the_End_of_the_Unive...](https://en.wikipedia.org/wiki/Voyage_to_the_End_of_the_Universe)

~~~
smuser
I believe it's "eXperimental Boom - 1" but I doubt they mind the coincidence.

------
divbzero
Are there other industries like supersonic and space flight where a competent
startup could attract top engineers in the field from government and academic
jobs? (This question is partly rhetorical. If you have a good answer… Go do
it!)

------
mirimir
Having built a glass/kevlar/epoxy kayak, it's a little mind blowing to read
about people building a supersonic airplane, using similar (albeit far^N more
precise) techniques.

~~~
0xff00ffee
Did you build a pygmy kayak kit by any chance? I did, it was the most fun I've
had building something in my life. The entire "epoxy plus fibrous material" is
truly a winning solution for so many applications, apparently hyper-sonic
wings, too!

~~~
mirimir
No, this was a high-volume play boat. About 35 years ago. And it wasn't a kit.
I was boating with a club with a shop, and members who knew what they were
doing.

~~~
0xff00ffee
Sorry, didn't mean to offend you by suggesting you were anything but a pro.

~~~
mirimir
Me, a pro? Never. But I learned from some serious whitewater freaks. I quit
because poor impulse control got me almost killed, too many times.

------
testfoobar
Amazing stuff. The blog post mentions tolerances in inches. Is Aerospace
engineering done in inches or meters?

------
pdoege
I'm surprised by the assembly tolerances. .05-.1" The F-35 is assembled to
.003"

The usage of control cables and pulleys is odd. I would have expected
hydraulic/electric actuation in a Mach 2+ aircraft.

~~~
mauvehaus
The F-35 is also low-observable. I'm a total lay-person on this one, but I'm
betting that the tolerances for achieving flight (even at Mach 2.2) are a lot
looser than the tolerances for being invisible.

~~~
pdoege
Yeah, the F-35 is actually milled down during/after assembly for low
observables. However, the Mig-21 can hit the same speeds as the XB-1 and it
has panel gaps visible from several meters.

I did some reading and the XB-1 does use hydraulics. From VEP and other
companies.

It looks like they will be using titanium leading edges to handle the heat
loads.

They are using a J85-GE-15. I don't think that will allow them to reach M2.2.
Closer to M1.7 or so? Depends on the inlets I think. (I was wrong on the
engines. They are using 3x engines, not the 2x afterburning that I was
expecting. So the speed looks reasonable)

------
kleton
Why are human test pilots still used in $current_year?

~~~
selectodude
Pilots have a better chance of saving the plane if something goes wrong,
software is less good at dealing with edge cases than an experienced test
pilot and in order to figure out what the edge cases are in order to
programmatically deal with them, you need a human to find out what they even
are and figure out how to fix them.

------
gok
Very exciting stuff. Even ignoring the supersonic aspect, there are some very
cool new ideas being applied to this aircraft.

------
tango12
This gives me a 400 on medium. Does anyone have an alternate link?

------
jupp0r
From their web page:

“Faster travel brings the world’s people, cultures, and experiences within
reach. Life happens in person, and at Boom we see breaking the time barrier as
a moral imperative. XB-1 is the first step in bringing supersonic travel back
to the world.” \-- Blake Scholl, Founder and CEO

The life happens in person part currently sounds like a relic from the past. I
hope Boom makes it through the travel recession.

~~~
babesh
They are targeting $5K for round trip tickets between NY and London. It is
really just making it faster for the rich to travel for fun or work.

Supposedly it is inherently 3X as expensive as subsonic planes from a cost per
seat mile point of view. It is basically a cheaper replacement for the
Concorde.

Also it seems that their biggest difficulty is coming up with suitable
engines. The engines that they need don't exist and there doesn't seem to be
an affordable way to create them.

See
[https://en.wikipedia.org/wiki/Boom_Overture](https://en.wikipedia.org/wiki/Boom_Overture)

It is definitely cool from a tech point of view.

~~~
nickik
I hate points like this. Pretty much all technology starts out for rich
people. I mean if you don't have supersonic flight at all its technology will
not improve either, neither will the economics of scale.

Air travel itself is already only for the rich, and travel in general is
mostly for the rich, if you want to look at it from the poorest in the world.

Elon made this point the best with Tesla, and in 10-20 years the cheapest
electric cars will likely be cheaper and better then current cheap gas cars.

I don't believe these 3x cost are actually 'inherent'.

~~~
tinco
They are though. Tesla is a horrible example, electric cars have better fuel
economy, so should have a lower TCO for daily users in the long run. Which has
always explicitly been Tesla's goal in the long run.

This plane, while awesome, is not a Tesla, it's never going to be as cheap as
a commercial flight, and it's certainly not going to make the world a better
place.

~~~
flyinglizard
Fuel cost is far from being the dominating factor in TCO; that would be
depreciation. I just ran Edmunds TCO calculator on an Audi A6: 5 year TCO of
$70k, with depreciation over 5 years being $35k and fuel only contributing
$9k.

Electric cars are nowhere near an affordable means of transportation right now
(that would be a Hyundai Accent), so GP point stands true.

~~~
robotresearcher
How does the A6 compare with Model 3?

~~~
rconti
That's absurd. An A6 is a much bigger/nicer car than a Model 3. I'd say the A6
is Model S territory, both in size and price. Of course this is complicated by
the lower running costs of the S, but the much more spartan interior, which
was basic even in 2012.

I've got a Model 3. It's a fantastic car, and as a BMW fan, I'd choose it all
day every day over a BMW 3 series. But I'd take the A6 for the same price.

~~~
robotresearcher
The parent comment said "Electric cars are nowhere near an affordable means of
transportation right now". The absolute niceness of an A6 doesn't seem
directly relevant to that. Model 3s are expensive to buy for a mid size sedan.
I was wondering about the TCO. I found an A5, M3 and Camry TCO comparison
(link below): M3 comes out similar to Camry, and way less than A5. I think the
M3 is a much more fun car to drive than the Camry. I haven't driven an A5.

[https://evannex.com/blogs/news/total-cost-of-ownership-
tesla...](https://evannex.com/blogs/news/total-cost-of-ownership-tesla-
model-3-vs-toyota-camry)

------
0xff00ffee
Man I'd be sweating like a pig if I was direct-applying epoxy to a prototype
so close to done. I'm used to code where trial and error is de rigueur, I
forget sometimes you only get one chance.

~~~
AWildC182
I work in aerospace software so I live in between those two realities. Much
like software, they'll do testing to make sure everything is bonded. They've
also done plenty of modeling to determine what the expected strength is and
they have a significant error margin baked in.

...They also don't call them test pilots for nothing...

~~~
Someone
FTA: _”Boom’s two test pilots were also onsite to verify that all aspects of
the wing met their approval.”_

I don’t know how well versed these pilots are in manufacturing this kind of
stuff, but I would guess that’s mostly psychological. But yes, it’s their
lives that are on the line. If this wing we’re to break or fall apart at
supersonic speed, I guess they (or one of them, if this is a single-seater)
are dead.

~~~
AWildC182
Sorry for the late reply... Test pilots by definition are pilots with an
engineering background. They're often seasoned aircraft mechanics and/or
aerospace engineers.

------
throwaway1777
Broken link

~~~
TheSwordsman
Working for me here.

Although, it isn't listed on their Medium profile page yet so maybe something
is up with it:
[https://medium.com/@boomsupersonic](https://medium.com/@boomsupersonic)

~~~
throwaway1777
Maybe something wrong with the medium app. It works on the web, but
redirecting into the iOS app leads to a 400.

------
person_of_color
This company is comma ai of aviation.

------
phkahler
I keep wondering if planes could benefit from the new materials developed by
SpaceX. If they really have a stainless steel that's significantly lighter, it
could be a game changer.

~~~
ghaff
As I understand it, they are using 300-series stainless steel instead of
carbon composites. Which relates to some novel techniques in manufacturing
parts from stainless [1]. But they don't have a lighter stainless steel, which
mostly doesn't make much sense because any steel is basically iron in terms of
weight--plus or minus depending upon the additives. Some steels are lighter or
heavier than others but within a relatively narrow range.

[1] [https://everydayastronaut.com/stainless-steel-
starship/](https://everydayastronaut.com/stainless-steel-starship/)

~~~
phkahler
They are supposedly developing a new stainless steel alloy. I've seen
indications it will reduce weight on starship. If its stronger, you can use
less of it which is effectively lighter. But I haven't seen real info on what
they've developed yet.

