It all comes down to this:
"There are far too many aerodynamic bandaids that are permitted to pass the current standards. Not just this particular airplane, but a whole bunch of airframes. If the basic aerodynamics won't pass without the pushers, pullers and now AOA induced changes to primary and secondary controls then a new design of the wing platform should come into play."
The way I interpret this, is that the plane should never have gotten the green light to fly.
More info about the MCAS here:
The crux is that safety agencies never mandated training on these new systems, and new procedures weren't created with them in mind. Worse still procedures from older models of the same aircraft (such as automatic overriding of auto-trim) were removed without re-training on that either.
Lion Air had to repair the AOA sensor multiple times (replace, then flush), but a single sensor failure should not bring down an aircraft; and if the AOA sensor is that safety critical then why did Boeing put two of them instead of three (i.e. for cross-checking readings)? Either it wasn't safety critical and Lion Air's actions are reasonable, or it was and Boeing cut costs on safety.
So the justifications blaming either the pilots (who didn't get training, because safety agencies told them it wasn't needed) or maintenance (who were repairing a non-critical sensor that turns out to be safety critical) are weak.
This is an excellent point. Boeing can't have it both ways.
The inherent problem with two is if one is feeding false data, you don't know which one, whereas if you have three (or more; but an odd number) you can cross-check the data and drop the faulty one.
It is a very common strategy already for commercial aviation and is called "voting logic."
> A more reliable form of voting logic involves an odd number of three devices or more. All perform identical functions and the outputs are compared by the voting logic. The voting logic establishes a majority when there is a disagreement, and the majority will act to deactivate the output from other device(s) that disagree. A single fault will not interrupt normal operation. This technique is used with avionics systems, such as those responsible for operation of the Space Shuttle.
But the real crux here is: Is the AOA sensor safety critical or not? If it can fail-safe then they can likely continue as it is currently designed. But if its failure state can cause an aircraft crash, then it becomes a safety critical component.
Fast forward to today where airport infrastructure is much more developed and these small/medium size airliners are being pressed into front line service including intercontinental routes. The aircraft has changed drastically to accommodate these changes through the years, enough that it may be time for a clean sheet design. They've changed just about everything on the air-frame from the fuel load/cabin length/wing to the avionics to make this all work.
Now, the other side of that coin is with systems. In theory this should be fine, but obviously isn't. It's hard to differentiate bandaids from regular systems and if either fails then safety is compromised. Obviously the amount of unnecessary systems should be minimized but as time goes on more systems WILL be added to gain the rewards of automation, which is a good thing. As such, we need to educate pilots on ALL of the systems, and rigorously test them before they enter service.
Additionally, if you do as the pilots want and achieve very high aerodynamic stability through the air-frame instead of stability control systems (fly by wire essentially) it reduces the aerodynamic efficiency of the airliner, particularly with current conventional designs.
It's crazy to me that that would be an acceptable compromise.
With regard to the other point, I don't think anyone is advocating for very high aerodynamic stability. That would be a B52 carrying nuclear weapons. It was designed to be extremely stable and forgiving. That being said, you don't want to rely solely on stability augmentation for trimming an airliner.
It reminds me of Air Canada flight 143, the pilots lost both engines and power. yet they were able to land the plane safely on an abandoned airport. I'm not sure if that would be possible with a 737 Max.
That is what the RAT is for, alternative electrical power. If the entire electrical system is down, ie electrons no longer flow anywhere anyhow, then everyone is doomed. But that is up there with the tail falling off. The are no backups for the wings/tail either.
When I say stability control, we're not generally talking about unstable or "relaxed stability" airframes where the system failing would cause a pitching moment to accelerate rather than converge and the aircraft would tumble and disintegrate. From an efficiency and handling standpoint, this would be ideal, but it's only used in tactical military aircraft where the crew can bail if there's a problem.
In most cases, we're talking about preventing stall in a swept wing aircraft. Swept wings are necessary to cruise efficiently beyond ~300mph at high altitude so they have to stay obviously, however they have VERY poor stall characteristics. As such, we have to do some things to prevent the aircraft from stalling such as playing with trim, using a stick pusher, etc.
Layman here, but 737, 747, etc. don't have swept wings, right? So they all cruise inefficiently... but are in fact stable... which is the opposite of what you wrote earlier? Sorry, I'm just really confused.
BTW since it's been tossed around a lot, good stall response is when the whole wing stalls at the same time and both wings tend to stall together, therefore you get a clean lurch downward in a straight predictable line. Bad stall response is one part of one wing stalling before the rest such that the wing drops and the plane has to be fought to avoid a spin or if extreme enough, a tail slide or extreme side slip.
They do, in fact, have swept wings.
Suppose, for instance, that an aircraft needs more yaw stability.
There's all sorts of design choices that could be made, but consider either A: a larger vertical stabilizer or B: automatic application of the rudder to damp oscillations.
The vertical stabilizer here is essentially a bit of metal. We know very, very well what can go wrong with bits of metal. Fatigue, corrosion, manufacturing defects, bad repairs... But, in 2019, we've pretty much figured out the failure modes of big bits of metal on an aircraft, and we generally know how to prevent and/or minimize them.
Now, the dynamic stabilization approach. We'll need gyroscope data (from the IRS, probably), a software model of flight dynamics (which almost certainly already exists and is running), and possibly faster servo valves for the rudder actuator.
This can work! We can formally verify that the control system we've created damps oscillations throughout all normal flight regimes. The gyroscopes are already redundant and well-tested. And you might not even need the faster servos.
Problem is, now avionics failures are even scarier. Will the stabilization here still operate when you get dropped into secondary mode? Probably not- so now, in unexpected situations, pilots need to keep in the back of their minds that yaw oscillations are more possible, that they may need to damp them manually, etc, etc.
Now you throw in some extra factors- turbulence, IMC (which would probably make detecting those oscillations manually that much more stressful), and trying to solve whatever problem dropped you into secondary mode in the first place... and you have something a bit concerning!
A bit of metal won't do that to you. We can make much better estimates of a bit of metal's reliability, and its failures are also less correlated- they aren't much more likely to crop up when you already have another problem.
That said, the cost of not using latest fuel efficient airplane would indeed be huge and the actual reliability of modern aircraft is very high and has been increasing over the years in which fuel efficiency also increased.
Sometimes, human can hit on a formula that produces objects that satisfy all the given parameters more fully rather than compromising on any of the requirement. But it's quite plausible that these formulas cannot be milked forever - thus the "Max" may be the point where tradeoffs stop working.
A quick look at the numbers suggests that a 737 MAX 8 is about 10% more efficient on fuel burn compared to a 737 300. That is not "massive" in my book and I'm more than happy to pay a little bit more per ticket if it means a higher safety margin.
Did you mean something older and less efficient than a 737 300?
As a curious bystander, I assumed using fly by wire tech to achieve stability would involve using control surfaces, which increase drag by their nature. How would an airframe that's naturally stable and doesn't require control inputs burn more fuel?
That said, an easy (but different) case to visualize is a traditional tailplane. The center of gravity on an airplane is in front of the wing so it wants to pitch down slowly. The tail pushes DOWN in the back to keep the nose up. Nose heavy planes are stable and forgiving but you induce drag because the wing needs to supply some lift just to counteract the tail which is producing negative lift. If you move the CG backward, you get less stability because the airplane wants to pitch up/down more violently with a control input but you have less negative lift from the tail.
We don’t build planes with training wheels anymore because the performance cost was too high. Planes are still the safest way to travel even without the training wheels.
I don’t think 737 MAX 8 pushes the envelope too far. I think they screwed up on re-training the disengage, and they may have screwed up on redundancy by only using a single AoA sensor, but I also am guessing the latest crash has absolutely nothing to do with trim.
Makes sense then, that those opposing aerodynamic forces induce drag.
The original design of the 737 did not have ovoid inlets.
You can see regular circular nacelle inlets on the 737-100:
and on the 737-200 here:
The ovoid inlet design was introduced with the 737-300, when the engine was changed to the CFM56.
His tweet sounds dumb but there is some truth in it.
As you say, planes and procedures have become very complicated. And I think there are only two options: making planes simple again which make them less efficient or let computers fly the plane and make the interface simple(r).
If you look at the rockets of SpaceX then you can say they are the extreme form of fly by wire and very instable when it comes to aerodynamics. But computers can land them within centimeters when they fall out of space.
So maybe that will be the future. Planes that are very efficient instable flying 'rockets' that are controlled by computers.
There really isn't. Automation is part of what has made flying safer over the years. Also, compare the cockpit of an Airbus with e.g. an old B737, the 300 series for instance. The Airbus cockpit is much simpler, in the sense that there are less gauges and knobs for the pilots to be concerned about. Automation has, over all, made things simpler and safer.
The most convincing popular article I've read on this topic is https://www.vanityfair.com/news/business/2014/10/air-france-...
It's far from clear-cut that the way automation is happening is advisable, however conservative it might appear to be, and I'm sure you'd agree that there are many confounding variables that make it difficult to say just what is responsible for the trajectory of aircraft safety. There's not much of a control group of advanced modern aircraft which omit automated features.
The wings need to be swept for efficient travel much over Mach 0.6 and these aero aids are needed for swept wings.
At this point, pushers and shakers are well-accepted fixes for aero that is not inherently recoverable.
this is an overstatement. airframe fuel efficiency is a undoubtable good thing vis a vis climate change, costs, etc. Obviously they've reached a point were the aerodynamic profile of a modern, efficient airframe is difficult to control via manual pilot input alone in some scenarios. This was the case for stealth technology with fighter/bomber designs.. the B2 for example has no vertical stabilizer and would not be controllable at all without fly-by-wire. Of course pilots will lament complexity and the loss of manual input. Regardless, the FAA wanted MCAS in the 737Max. Augmenting human input in the face of instrument failure and possible human failure is an extremely hard problem and uncharted territory for the industry. Doesn't at all mean its a not a worthy goal or that the designers or regulators had ill intent or negligence.
To counteract this they introduced the MCAS system. They would not have needed this if they hadn't "retrofitted" big engines on an old airplane design, but instead started from scratch. The B737 MAX is not really a modern aircraft, but a heavily modded old design.
You can design an aircraft just like this that won't have those characteristics. You'll just need to pay to get it certified and then airlines will have to pay to train their pilots. Instead, Southwest wanted the band-aid fix, and Boeing obliged them.
If it is cheaper to invent something like MCAS than to properly adapt the airframe, then maybe the processes that would be used for the latter are ripe for some efficiency optimization.
The lack of feedback from the MCAS system is probably the killer here.
How am I supposed to know that MCAS is operating, and how do I know when to hit trim cutoff switches to override it? You don't want to ever be asking "what the heck is the airplane doing now?". Watching the trim wheel to check if it's spinning nose down all the time isn't going to work.
The behavior would be similar to runaway stabilizers, though, for which B737 pilots have memory items to perform (turn off the trim). This would have solved that problem. However, several other warnings and alerts, like stick shaker, might have been going off at the same time, making the situation chaotic and problems hard to diagnose.
I'd rather wait for formal investigations (e.g. NTSB-style) before jumping to any conclusions.
As an example, Norwegian (who has 15 of them) said they weren't grounding them as late as this morning, but now they'll have no choice. They use them mainly for their medium flights between scandinavia and southern europe (Nice, Budapest, Tenerife etc). No way they can do that without flying over Germany and France. It wouldn't be very good optics if they swapped their MAX'es to domestic use to free up regular 737's for flying over the continent either.
On the other hand, if your plane gets stuck in a foreign country the bill just for parking the thing could be massive. Better to get it back while you still can.
Especially if there’s some repair required before next takeoff.
2/3 of those planes are flying back to Istanbul vs their destinations. Does Norwegian have a maintenance hub there?
(emergency landing in Iran, can't get parts there because of sanctions)
> From the effective date and time of this AD, do not operate the aeroplane, except that a single
non-commercial ferry flight (up to three flight cycles) may be accomplished to return the aeroplane
to a location where the expected corrective action(s) can be accomplished.
So they are allowed to be ferried in certain situations.
I wouldn't, haven't all the problems so far have been during takeoff? So once you're cruising you're safe from them?
So basically another 1.5h flight back to Oslo, a few hours wait, then on a replacement plane (thank god) with another flight back to London. A long day.
I can, however, understand it. As with this 737 Max-8s they did not want the plane grounded in an airport where they don't have a full service centre with parts etc. Had it only been a few years later we could have continued as they made Gatwick one of their major hubs with probably full stock of parts.
Though I do have a rule of preferring flying out from an airport with a "local" airline, as they are quite likely to have parts and chances of spare or frequent incoming planes to shuffle around to.
Related, Norwegian plane was stuck in Iran: https://eu.usatoday.com/story/travel/flights/2019/01/10/norw...
The pilot strongly implied that had I been on the British Airways flight, we'd have continued to the destination: BA would have flown their spare pilot + spare plane + repair crew out.
But Easyjet didn't have a spare crew.
Edit: Two are Turkish, only one is Norwegian
I wonder if, say, Germany, waited until its planes had to chance to land before closing their airspace, while other countries/companies, like Norwegian got caught by surprise.
Convenience over safety?
Total speculation on my part.
There hasn't been much fleet renewal in the German market in recent years, just lots of consolidation (it's actually a bit of a lottery to buy a ticket in advance due to all the bankruptcies)
> Diversion to Shiraz, Iran December 2018
> A Norwegian Boeing 737 MAX suffered an unspecified technical failure over Iran in December 2018. The pilot made a precautionary landing at Shiraz Shahid Dastgheib International Airport without incident. Spare parts required to make the aircraft airworthy were not available in the world outside the United States, which has prohibited exports of technology to Iran. Two months later, the almost-brand-new aircraft remained stranded in Shiraz and subject to seizure by the Iranian government.
> On 22 February 2019 the plane was ferrried from Shiraz to Stockholm as DY8921
If you're a reasonably sized international airline, it seems like a reasonable possibility that you'd have to (or want to) land in a territory that the US in unfavourable toward. Why take the risk?
And if you want something the size of the best selling variants of the A320 family and 737 MAX you have essentially no choice.
"The US approval for the transaction was needed, as Sukhoi aircraft contained more than 10% (22%, according to state news RIA) of American-made parts."
And I thought Europe were lifting their Iran sanctions? They're trying to get a non USD payment system sorted so they can continue trade after the US pulled out of a deal.
Nope, since the 2015 nuclear agreement with Iran, Europe has no sanction against firms that commerce with Iran. However, since USA pulled out of the agreement, USA threatens european firms that commerce with Iran. The agreement is however still in place.
The MCAS system and the way it was introduced sound a little like a patch, and slightly haphazard.
While training & runbooks and procedures are important, take-off is a busy time, and the Max-8 is (afaik) intended to operate very-nearly-like a standard 737, so it's not inconceivable that pilots wouldn't have time or intuitively know how to handle this situation.
Ultimately any vehicle/software/tool is going to be safest when the responsible designer makes it intuitive and reduces the possibility of failure cases rather than adding workarounds or runbooks to patch over them and/or disclaim the liability.
Anyway, it seems like it could be early to strongly assign blame or critique until we know how serious the issue is.
Generally do agree with grounding the Max 8 fleet as a precaution, and also given the poor engineering smell around the MCAS.
But not keen to assign blame/failure and damage reputations until there are credible investigation results, or without providing references.
It seems more likely that the plane suffers from some elemental design problems that were insufficiently patched over to pass inspection in order to protect the already invested capital.
They are just blaming the victims, trying to let those already killed pilots to take responibility for their faulty designs.
Norwegian Air and Norwegian authorities had the same information (or indeed lack thereof), but did not act until now. Given the known similarities, and the lack of data that rules out a problem with the B737 MAX, the responsible thing is to err on the side of caution.
People are pattern-matchers, and if 99% of flying the plane is the same except the part that will kill you if you don't do it the new way--well, people will do it the old way and die. That's infinitely more true in an emergency situation where you tend to fall back strictly on training and instinct.
If you want to jar people into different behavior, the interface needs to be different as well. Otherwise it looks like the same old contract.
I think many of us kind of know this from GUI/API/whatever design, but there's no reason jet planes would be any different.
Considering that pretty much any criticism can be dismissed with "better safe than sorry, also everyone else was doing it, we had to consider the optics" it makes perfect sense to step in line and ground them like everyone else. Not doing so would just be stupid when there's near zero downside to the people making the call.
It's like highway traffic. Sure you can obey the letter of the law but when everyone else is doing something drastically different your exposure to risk is minimized if you just do what they do whether it's right or wrong.
In particular, ferry flights are allowed with certain limitations.
> "[...]do not operate the aeroplane, except that a single non-commercial ferry flight (up to three flight cycles) may be accomplished to return the aeroplane
to a location where the expected corrective action(s) can be accomplished.".
Doesn't this just say the 737 MAX can be flown only to undergo future maintenance that'll resolve whatever the current issue is, unless another notice is posted clearing it?
I've always held the FAA in high regard, and think they do a good job. Are they really being negligent here? Or is the media just looking for something to spark outrage?
Can anyone with more specific knowledge of aircraft safety weigh in?
The US can tacitly blame "third world" pilots all they want, but with 300 people dead already, I think it's important for the FAA and Boeing to say exactly what is going on, especially since the planes are in use in the USA.
There is a debate over if the plane's hardware, software, or pilots are at fault-- either the planes should be grounded or the exact protocol should be published all over for the world to know, since it is the passengers' lives at stake.
EDIT: The Economist source that estimates a plane's p(crash) is questionable, for a passenger plane. If anyone wants to dig into this further, I found this source too: http://www.baaa-acro.com/crash-archives
Meaningless and misleading comparison at best.
According to numbers released by Boeing  itself, the original 737 designed back in 1967 had a hull loss of 1.75 per million flights, the 737 NG designed in the late 1990s to early 2000s had a hull loss rate of 0.27 per million flights. So Boeing 737 had a 7X less likelihood to crash as the results of 30 years of improvements. 25X difference is going to send the highly unsafe 737 MAX design back to the WWII level. Now think again whether WWII era aircrafts with similar crash likelihood should be allowed to carry passengers in huge volume in 2019.
You number proves one thing and one thing only - FAA has the legal and moral obligations to ground all those highly dangerous 737 MAX immediately.
I have a suspicion that if you were to remove all instances of terrorism and look at the crash rate of Boeing vs Tupolev, almost all Boeing planes would be way better except for the MAX 8.
That is probably a meaningful piece of data too.
The FAA and NTSB are very good at what they do, one of the very few examples of government services that work well together with industry, give them some time.
If we assume this airplane is safe, we can apply that probability to it and then ask P(2 Crashes|N Miles & 350 New Planes).
You would then have a probability for this just being bad luck, and compare that against your prior that this is a safe plane.
I haven’t done the math, but my gut says it would point to grounding the plane.
The MAX8 fleet has been operational for about six months. Assuming 3 flights per day: 350 * 6 * 30 * 3 = 0.189 million flights.
To estimate the probability of two accidents, we can use a Poisson distribution with x = 2 and μ = 0.189 * 0.39 = 0.0737
P(x=2) = e^(-μ)μ^x / x! = 0.25%
I.e your gut feeling is correct (if my math is correct, that is). If one uses the estimate from a sibling comment of 1 crash in 11 million fights, the probability decreases further to 0.01% Actually the correct calculation is:
1 - P(x=0) - P(x=1) = 0.26%
since we are looking for the probability of there being more than one plane crash -- not just the probability of there being exactly two plane crashes.
Look at things like Alaska Airlines Flight 261  - safe airframe, deficient maintenance, plane loses all pitch control and impacts ocean. Yes, this still means that Boeing needs to improve things - single points of failures are never OK on a plane - but it also doesn't (IMO) mean the plane is fundamentally unsafe without those fixes.
(You can pretty much always make statistical inference, with uncertainty going up with the lack of data)
If we assume that the average MAX 8 has been in service for a year (first delivery was a little less than 2 years ago), and conducts 4 flights a day, we get this  - a mean of 1/250000. Still worse than 1/11000000, but only by a factor of 50 instead of 50 thousand.
I suggest you try the math as the odds are reasonably high.
This changes if you start talking about crashes since the first commercial flight, but those are again different numbers.
"Guts" are notoriously good at statistical inference
And no, the FAA is not really that good, general aviation pilots die all the time from negligence and the FAA doesn't enforce the rules when pilots violate them (in particular low altitude flying).
That being said, the government gives general aviation pilots a fair amount of freedom once they get their license. There are rules and they are enforced; particularly when violations put the general public at risk. But there's also recognition that it's quite possible to regulate GA out of existence like a lot of other countries have, and that has pretty negative consequences in terms of pilot availability for other purposes. Therefore, regulations scale with the amount of danger the public is exposed to.
For example, ultralight aircraft (single place, <254 lbs, <=5gal fuel, <=55kts) are virtually unregulated; the idea being that they're so small and light that they aren't much danger to others. LSA/sport (1-2 place, <=1320lbs, <=120kts) are regulated; require a license and inspections but less stringent than a private license, and so on. Private licenses can't be used for commercial purposes, and generally speaking more training and endorsements or ratings are required for eg. aircraft with multiple engines; those that are >=12,500 lbs, those that land on water, those that have old-school landing gear, etc. etc.
§ 91.119 Minimum safe altitudes: General.
Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:
(a)Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.
(b)Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.
(c)Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.
(d)Helicopters, powered parachutes, and weight-shift-control aircraft. If the operation is conducted without hazard to persons or property on the surface -
(1) A helicopter may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section, provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA; and
(2) A powered parachute or weight-shift-control aircraft may be operated at less than the minimums prescribed in paragraph (c) of this section.
(a) Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.
A perfectly good airframe can have its reputation ruined with 2 incidents in a short time period.
"the plane is safe to fly with additional training, when given"
If the 737 MAX planes remain in the air in the USA, Boeing and US Govt are de facto saying "third world pilots clearly just don't understand how to fly our planes".
If they ground the planes, they de facto admit there is an actual safety issue.
If that is ultimately the conclusion, then it still gives the FAA and EASA a black eye, since they allowed the aircraft update without additional training for MCAS.
Best case scenario for Boeing is that the Ethiopian Airlines crash turns out to be something else. If it is MCAS related Boeing, the FAA, and EASA amongst others that green-lit the update without training have a lot to answer for.
Here's the thing. The additional training is not strictly necessary. The same procedures pilots are already trained for in previous models should have saved the aircraft. Unless investigations turn up a new problem.
Of course, one could argue that, by disclosure changes to the system, that the pilots would be able to react faster. But that's not really for us to decide.
0: Which action, if either, is definitive might differ if the stakes weren't inconvenience vs death, or if the FAA openly didn't care.
Not saying I think these are completely random. But since we don't even know the cause of the Ethopian crash yet, who's to say? The causes may very well be unrelated.
If it's random chance, Boeing should be able to prove it is random chance. Until then, the FAA should ground them.
The Ethiopian Air copilot only had 200 total hours of experience. In the US, you need an ATP certificate with a minimum of 1500 hours to even be a first officer.
Before we start throwing sand at the FAA, why not ask how a 200 hour pilot gets into the copilot seat of an airliner. Let’s also ask why Lion Air failed to fix a problem with the airspeed indicator. During a previous flight the day before the crash, the pilot reported a problem with the airspeed indicator and deactivated the anti-stall system. Lion Air didn’t fix the problem and the airplane crashed the next day. But that’s Boeing’s fault? Lion Air is a shit airline with a horrible safety record. Southwest Airlines uses only 737s and you can count their major incidents on one hand and their fatalities in over 47 years? Just 1.
Lion Air fatalities? Hundreds over multiple incidents. Ethiopian Air? Much safer than Lion Air, but much less safer than Southwest. Ethiopian has a fleet of 108 airplanes and Southwest has a fleet of 754, including 35 Max 8 planes — yet not a single incident despite flying an order of magnitude more frequently than those other airlines.
Air Canada has 24 8 Maxes in the air as does American. Along with Southwest, that’s hundreds of flights per day without incident, but then there is a crash with some third world Lion Air plane where maintenance is provided with proverbial duct tape and Ethiopia Air who has a student pilot as the first officer? Perhaps instead of grounding specific airplanes, we should ground specific airlines, because it’s clear than Ethiopian and Lion Air ought not be flying until they can figure out the basics such as maintenance and pilot training.
They have jurisdiction over the type certification as the responsible regulatory body for the nation of origin of the airframe.
These supposedly awful third world pilots and aircraft engineers have somehow been managing to fly earlier models of the 737 for decades, but when they upgrade to the MAX variant somehow two of them crash in quick succession?
That either indicates that these two events are freak accidents, or that the MAX shouldn't have the same type rating, the latter of which is on the FAA and Boeing.
Is it fair? Maybe not all of it. But I think it's completely predictable.
Hasn't news always been for-profit? If not: which news organizations (newspapers, magazines, wire services) have been run on a non-profit basis?
The only recent change (IMHO) has been higher time-to-market pressures (minutes versus hours/days).
Honestly why not ground a few hundred planes just to be safe? It doesn't bother the Netherlands or Singapore. There are other aircraft, nobody is running out.
Those dastardly politicians and bureaucrats, how dare they consider the broader consequences of their actions. /s
Those poor politicians and bureaucrats, how terrible that they be forced to consider the broader consequences of their actions for once. /s
I'm not going to lose any sleep over politicians having to deal with a complex trade-off for once.
It’s mean, but I’m not surprised, given the money in the game, that Europe is acting up much faster than FAA for a Boeing airframe, and the opposite for an Airbus/DC airframe.
2) McDonnell Douglas (maker of the DC planes) is now owned by Boeing and was an American company.
I don't understand this logic. They are essentially risking their entire company over the safety of this plane. If something happens now they'll be driven to bankruptcy at record speed.
Right now, 737 Max Fleet is the deadliest plane per mile that is in the air , by a wide margin. Maybe it's an anomaly and the rate is much lower, but by the same reasoning, it could be worse. I'm not flying on one, and my opinion of Southwest and American is at a new low.
.. the MAX aircraft has 17,000 recordable parameters and Southwest has compiled and analyzed a tremendous amount of data from more than 41,000 flights operated by the 34 MAX aircraft on property, and the data supports Southwest's continued confidence in the airworthiness and safety of the MAX. ... SWAPA also has pushed hard for Angle of Attack (AOA) sensor displays to be put on all our aircraft and those are now being implemented into the fleet. All of these tools, in addition to SWAPA Pilots having the most experience on 737s in the industry, give me no pause that not only are our aircraft safe, but you are the safest 737 operators in the sky.
No, that only means that they believe this will improve pilot's situational awareness. You don't need that feature to override uncommanded trim.
Until the FAA says the aircraft is unsafe, your opinion of these airlines is misplaced. They went beyond what's legally required and added an additional safety feature.
Southwest exclusively flies 737s. They have one of the largest pilot corps for that type. The airline has good safety and maintenance records.
What’s the non-monetary harm in grounding until more is known? They are a small percentage of their fleet.
Southwest have been flying since the 1960s, and have I think a total of (3) fatalities. No relation or association to them but the operator and their training matters. Southwest are by any measure one of the safest airlines in the world.
Two lost aircraft. Both new. Both with the same symptoms. Under conditions you would not expect to lose an aircraft.
That's a really really bad sign.
Is southwest refusing refunds? Not doubting you, just asking if there has been a story about it.
I hate to say it, but given the track record for appalling incidents happening with airlines in the US, I'll buy that dip.
But all that profit, would someone think of stock holders please!?
No wonder McDonald Douglas changed the DC-10 into the MD-11.
Which is a lot, considering DC-9 and DC-10 are known for all sorts of crashes, including losing the same door 4 times for the same reason, each time with deaths. Ah, and who doesn’t remember the Concorde crash. Provoked by bursting a tyre on a piece lost by a DC-10. The airplane that literally falls into pieces.
I guess it is natural for governments to promote local industries but the cynical me thinks that corporations have captured our government so they don’t act in the public interests.
From the CAA: https://www.caa.co.uk/News/Boeing-737-MAX-Aircraft/
The 737-700, -800 and -900ER, the most widespread versions of the previous 737NG, are replaced by the 737 MAX 7, MAX 8 and MAX 9, respectively (FAA type certificate: 737-7, -8, and -9). The 737 MAX 8 entered service in May 2017, and the MAX 9 entered service in March 2018. The MAX 7 is expected to enter service in January 2019, followed by the MAX 200 later in 2019, and the MAX 10 in 2020.
The only difference, again AFAIK, is the passenger and cargo capacity, length, and the range.
The avionics are the same but because the planes have substantially different air-frames, the software parameters and possibly some functionality will differ. It's not unreasonable for differences in these flight parameters to be a factor.
Basically, the larger/more powerful/further forward engines on the MAX would cause the airplane to behave differently to other 737 variants in some situations, and MCAS is designed augment pilot input and allow the pilots to fly the planes as they would have flown other 737s (and allows pilots to fly MAXes under the same type ratings as previous 737 models). However, in edge cases (in the case of Lion Air, erroneous sensor input) the airplane might do something totally different from other 737 variants. Evidently Boeing didn't even require pilots to be told about MCAS, because all it (supposedly) does is make a MAX feel like an older 737.
Given the trade tensions the US has with both China and the EU and the fact that both are offering competing products (Airbus more so), this sounds like more of a political move. In the case of the EU, the WTO ruled that Airbus was illegally subsidized by the government that has now banned a Boeing aircraft while it has the green light to fly in the US.
As swampy as the US government is, the EU has it's fair share of payoffs etc.. I expect this to further heat up the trade war.
- Flydubai Flight 981
- Tatarstan Airlines Flight 363
Of course that's all speculation since we don't know much about this particular crash, but that's the main issue with them.
Bascially MCAS is a hack to cover a problem raised by trying to save money by pretending it's the same as a 52-year old airframe. Instead of just saying "let's do this properly ” and certificating as a new design with appropriate design features.
Boeing's main argument is that the procedure for dealing with runaway trim is completely unchanged compared to other planes, so this shouldn't require any additional training.
I understand their reasoning, but it seems odd to not even inform that there was a change, so that this would be more on top of the pilots minds. It's even worse that the system engages as soon as flaps are retracted. Since 737's usually take off with at least some minimum flaps, and retract them soon after take-off once enough airspeed has been attained (but while the plane is still at low altitude), this is quite dangerous. Pilot workload is high at this stage and there is limited altitude to recover.
That said, since this issue is on top of everyone's minds, and US carriers have added the optional safety indicators, we are unlikely to see a crash any time soon. Pilots will be jumping to the override switches at any sign of trouble.
This is a good point. And very concerning!
It’s not yet known if this latest crash is in any way related to the first (although I have several outstanding wagers against this being the case).
Totally backfired in that regard though.
I can imagine it looks good on the marketing material, 'no pilot retraining required!', but as far as I understand from all the analysis so far, it's actually not that hard to disable the new MCAS system and prevent a crash. As a pilot you only need to know it is there, and what happens if it somehow fails.
I would be surprised if they had sold even a single plane less if they advertised it as 'very minimal pilot retraining necessary'.
That might be enough for the plane to need a separate type certificate, meaning hundreds of millions of dollars expenses for Boeing to get it certified, and full new-type pilot training costs for every airline to fly the aircraft. (Plus, time, and ongoing crew management to juggle pilots certified on one but not the other.)
You don't even have to know it is there. All you need to know is "hey, auto trim is acting very funky today and I'm having to fight it. Better override.". And hit two switches.
> I would be surprised if they had sold even a single plane less if they advertised it as 'very minimal pilot retraining necessary'.
They were likely afraid that it would require a new type certificate.
Unless you believe your instruments (AoA reading high) and assume the plane is actually doing the correct thing.
If something else made the engine(s) catch fire and become inoperative, and the MCAS system enabled correctly due to low airspeed/stall conditions, but was fought by the panicked pilot(s) resulting in an unrecoverable stall, it's an entirely different story.
Yes, it may turn out that this incident bears no relation to the Lion Air one, but I think it's much too early to make any such assumption.
https://www.youtube.com/watch?v=MQWYhsYfMxE (jump to 1 minute for an example, found in an earlier HN thread).
They didn't come up with a common sense solution, doing so would have costed many billions for a new airframe with longer legs for the landing gear. This is how I understand the problem, coming from a design compromise and organisational groupthink.
Clearly this is my armchair speculation however I suspect there will be lessons to be learned from this that run along the lines of the 'Vasa' rather than the 'Comet'.
The Vasa story crops up on HN from time to time, it was a top heavy Swedish ship that sank after launch in light winds many centuries ago. The spec had changed with more gun decks added and groupthink drove the 'pride of the fleet' project forward. The launch date happened and it sunk.
Jeez. How are pilots supposed to land that thing in heavy wind scenarios? One wind blow at the wrong moment and it will make ground contact.
The 737 MAX engine clearance from the ground isn't very unusual. E.g. the A320neo is below 56 cm.
The older versions of this aircraft have the same ground clearance and have had for decades.
If we speculate (e.g. before the facts are in) that this was similar in cause to Lion air incident, then I would be curious to know how often AoA sensor has malfunctioned and|or MCAS has otherwise gone haywire and pilots have needed to revert to manual control during the two years of service MAX8s have had.
I think most people don't realize just how much stuff can be broken on an airliner and it still deemed safe to fly. And it happens all the time.
Sure, airliners might fly all the time with a missing seat number or a broken overhead bin. They're big, complex machines. But if you're implying that it's routine to fly with broken sensors, then no. That's not true.
Picture being at the wheel of a self-driving car, with an obvious crash looming, and the car refusing to let you, the driver, take back control and steer the wheels or step on the brakes.
Small typo: He says "forward and up" in the video.
Here's a good answer from Reddit:
Based on what I read, the truth is a lot more complicated. The MCAS doesn't work the way most people seem to think it does. Maybe it is a factor in the crashes. We don't know that yet.
Maybe there is nothing in particular wrong with these planes, and they were just hit with two random accidents.
2 Boeing 777-200ERs down within three months of each other (one was shot down by Russia and the other is speculation)
I don't think you could say Malaysia Airlines was at fault for MH17, but it's hardly a good example of a null hypothesis. Since e.g. if BA was operating the same flight at the time it wouldn't have been anywhere near Ukraine.
 To a reasonable extent, of course, nothing can ever be proven 100% safe.
The hardware, software, and human systems are so intertwined that it likely involves all 3, even if the route cause can be isolated to one.
That being said, there hasn't been much specific information about the cause released yet, that I've heard.
"You don't have to do anything, the plane will fly itself. Unless there's a catastrophic emergency. Then you better remember everything you haven't practiced from 18 months ago" seems like a failed implementation.
There's a checklist procedure for almost any scenario they will run into (of course not every). This exact issue was seen by other airlines and the pilots followed the checklist procedures to safely regain control of the plane as expected.
In theory, these checklists are optimized to resolve these issues and regain control as quickly as possible while ruling out other causes. It is very rare the correct course of action for the pilot differs from the checklist procedure.
There is 0 expectation that the pilot should remember everything. Pilots are trained specifically to communicate with each other to go through these checklists as quickly as possible.
That being said, there is a major concern that this issue will popup while taking off and being too low to the ground to properly follow procedure in time to recover control of the aircraft.
Apparently, the plane thought all was well, just needed to point the nose of the plane down a wee bit.
Reviewing the video below - it appears to still line up with this. He doesn't mention the actual memory items changing. His explanation is the pilots starting using the wrong memory items because of information overload.
Example - They could have been going through the stall memory items instead of the runaway vertical stabilizer memory items.
(Air Traffic increased ten-fold since 1970, while fatalities went from 3,500 pa to a few hundred)
When a typical civilian passenger plane throws everything up and yields control to its pilot, the pilot gets 10+ minutes to fix it, helped by a copilot, mountains of checklists and a direct audio line to air traffic control.
Nothing to do with the 5s you maybe get when your Tesla yields.
The general idea is that there is an auto-trim system meant to stop the plane from stalling. But when it gets bad data from a faulty sensor it tries to crash the aircraft (short version). Pilots, all pilots, are trained to recognize this and override the system, but this aircraft requires them to do some things slightly differently. Specifically, they have to shut down the system rather than manually work against it. Difficulties arise where there is a disconnect between what the pilots think is happening, what the systems think and tell them is happening, and what the aircraft is actually experiencing. So this is an interaction between an automated system (software) a potentially faulty sensor (hardware) and pilot training. It is a complex problem that will take a while to fully understand and solve.
These crashes happened because Boeing tried to market the plane as not requiring retraining in order to boost sales to airlines.
"What the hell is happening?"
"Flip the cutouts!"
Why that wasn't mandated by the FAA I have no idea. Instead the pilots are expected to systematically analyse the options whilst trying to stay airborne.
Lol. Thanks for the downvote all below. Thanks for proving my point about the change of behavior.
We don't know it had anything to do with pilot training until the investigation is actually finished. To say it's pilot training is pushing Boeing's narrative.
> Following the Lion Air crash, US aviation authorities issued an emergency directive to carriers to update flight manuals with information on what to do when the aircraft’s anti-stall system is triggered by erroneous data from what’s called an “angle-of-attack” sensor. The flight system can react to that data by pointing the plane’s nose sharply downward. Boeing, meanwhile, directed airlines to a checklist in manuals for stabilizing the aircraft. Pilots said the crash and the directives that followed were the first time that they were made aware of these changes to the flight system.
That way, if you have one faulty sensor, it gets outvoted.
The MCAS system in the new 737-MAX's only have 2 AoA sensors, which means a single faulty sensor can cause bad things to happen.
That's pretty damning if true.
The reddit thread linked from elsewhere says the same thing.
The preliminary report on the Lion air crash (http://knkt.dephub.go.id/knkt/ntsc_aviation/baru/pre/2018/20...) says they replaced and tested the AoA sensor 2 days prior.
They repeatedly refer to the AoA sensor using only singular nouns everywhere.
Given the report says it was giving faulty data and that was used, the only way this can occur is either:
1. Their are multiple sensors and the software is broken
2. There is a single sensor
Given all other data, i'm going with #2 :)
Nobody has been enterprising enough to publish the MAX8 troubleshooting/etc manuals online, if they did, you could easily verify this.
If true than that's preposterous.
Do you have anything real to add here other than "I am Very Smart and everyone else is not"?
For example, whether it is a fly by wire system or not does not change anything about what i said about the sensors.
That would make sense, but unfortunately it's not the way they're actually implemented. Several incidents with Airbus aircraft were due to one AoA sensor's faulty input being allowed to trigger uncommanded pitch down events, instead of the one faulty sensor being outvoted by the other two.
I agree having only two sensors is even worse.
It's also not the first plane to crash because of software reading bad data from bad sensors. Or the last.