In response to Boeing 737 Max Unsafe to Fly: New Scathing Report by Pilot and Software Designer, I received a huge number of comments and emails.
Not Just Boeing, Airbus Had Similar Issues
The most interesting response came from Kevin Sullivan, the captain of Qantas Flight 72, an Airbus that made an emergency landing at Learmonth airport near the town of Exmouth, Western Australia following an inflight accident featuring a pair of sudden uncommanded pitch-down manoeuvres that severely injured many of the passengers and crew. The injuries included fractures, lacerations and spinal injuries.
That emergency landing was on October 7, 2008. The Australian Transport Safety Bureau investigation found a fault with one of the aircraft’s three air data inertial reference units and a previously unknown software design limitation of the Airbus A330’s fly-by-wire flight control primary computer (FCPC).
Sullivan Responds
Hello Mish,
I was the Captain of QF72 in October, 2008. The Air Data and Flight Control Computers teamed up to generate automation confusion and then maneuvered my Airbus A330 in similar fashion to the MAX accidents. 119 passengers and crew were injured and a Mayday declared for emergency divert to Learmonth airfield in Western Australia.
This article you have posted is the best so far on the MAX accidents.
I have written a book about my accident flight entitled, “No Man’s Land: The Untold Story of Automation and QF72“. It will be released next month through Harper Collins publishers, and I see Amazon will have it too.
I lay it on the line, with a few stories from my US Navy days and the training I received there that helped me save the day. I am lucky to be a survivor of this colossal failure of technology.
There is more to come from all of this.
Cheers,
Kevin Sullivan
Chilean 737 Pilot
Hello Mish
Boeing went beyond the red line.
I’m a retired captain having flown the B737-200, B707, B767, A340, A320 and others. I flew for more than 40 years.
The Boeing 737 Max is poorly designed. A complete new design and a new name is needed.
Name Withheld.
The Chilean pilot says he worked for LAN Chile, now is LATAM Airlines, the merger of LAN and TAM. His email address country code was from Chile.
Air Expert
I cannot vouch for the following comment at all, but it rings true. I corrected some typos. This comment was posted on my blog. The above comments were via email.
As an industry expert, I have flown the 737 max as a line captain and it was my 12th type rating. The MCAS is the tip of the iceberg, this airplane is majorly flawed not only aerodynamically but also technically.
Never before have I encountered such strange behavior from an airliner.
Pilots are now younger and more inexperienced. A bad stall indication system will only exacerbate the situation. Adding a light or more information to digest will only delay the response.
The 737 Max automation is very weak compare to other Boeing products and especially compared to Airbus.
I have flown the Boeing 767 which first flew in the early 1980’s. It is more advanced that the 737 max. Why? The 737 max is an older design and has shown the limits of what this fuselage could bring. It’s like having an IPhone 10 that you have to plug in a phone jack to get internet.
I asked to be removed from flying the 737 max ever again. I don’t trust this airplane and I have 17,000 hours as a line Captain and have been an instructor for close to half this time.
Why should the public trust the airplane? I don’t.
Landing Gear
This is another comment from my blog. I cannot vouch for the authenticity, but it is a very detailed response, so detailed, that if it is wrong, industry experts will quickly spot any errors.
Dear Mish,
15 years ago, we had a few chats on your blog about a matter here in the Middle East (where I still am). At that time, some people had difficulties accepting the facts in one of my comments. I really appreciated your understanding. Since then I have been a rather occasional reader. But the 737 issue brought me back to chip in some of my experience.
I am happy seeing that you having toughly carried on with your blog through the times.
Back to the 737, since I have spend a handful of years in the same business (in the presidential fleet of the country at that time) I fully understand what happened and I can only confirm what Gregory Travis described.
He is right. The main culprit is that the Boeing management didn’t wanted to accept the fact that the time of the design of that air-frame had come. Everybody should remember the concept year of the 737 was when Gregory and I were born: 1964!
There is another culprit that Gregory did not mention, the landing gear.
The first generation passenger jet aircraft had the engines mounted in the root of the wing (Comet, TU 104) or on the tail (Vickers VC10, MD80/90, DC9, Tupolev 134/154, Ilushin 62) both designs were proven awful to maintain.
I worked on a machine with tail engines and I can tell you it was a pain to maintain the engines standing on the ladder changing the filters and others overhead. Airline personal loved the Boeing 737 because the engines were fixed on the wings with the thrust line approx 1.4m above ground which means the center line of the engine was at chest height and you could work on the auxiliaries normal standing with the hands straight forward. To realize this, the landing gear has been kept short. Go to wiki look at the pictures for the 737 and then compare with the photos on wiki A320. You can clearly see how short landing gear of the 737 is. [Note: I added those links. I am not postive they are the correct ones.]
Fitting a high bypass engine with larger fan would be possible by enlarging the landing gear by 50-80 cm. However, the landing gear retracts inwards and if you make the landing gear too large the wheels hit each other. Furthermore, the wheels will require space inwards and that must be cut out from the airframe, but there is the central span of the airframe which cannot be touched at all, otherwise the cabin will fold during flight.
That created headache for the designers when they wanted to fit the new high bypass engines from 1986 onward. So the engineer and says “no problem”. We can move the hinge points of the landing gear more outward then we can enlarge the landing gear and make space for the engines.
The hinge points of the landing gear are the most impact stressed elements on the whole aircraft. A change in the hinge points means you change the whole integrity of the wing. Getting approval from the FAA for that would require extensive simulations, prototype building, and a crash test before approval. That’s a lengthy process so the Boeing management said No, find another solution.
So the engine was raised as Gregory mentioned it and the negative angle in the thrust line flattened. By doing so the force vector on the wings have changed.
Additionally, and as described by Gregory, the larger nacelles cause additional lift reducing the counter momentum further. The result was an aggressive behavior of the wing in the critical angle of attack zone.
Wrapped in the prior unimaginable progress of the last 2 decades we tend to believe everything can be solved with computers. Nobody wanted to accept the physical boundaries of the hardware anymore. Thus came the idea to tame the aggressive wing with the computer controlled software.
The rest, Gregory nailed perfectly. I hope I have not bored you with this details.
Thanks to all for the comments. By the way, the Seattle Times reports Doomed 737 MAX’s pilots apparently followed Boeing’s emergency directions.
Just a week after the Oct. 29 Lion Air crash, Boeing sent out an urgent bulletin to all 737 MAX operators across the world cautioning them that a sensor failure could cause a new MAX flight-control system to automatically swivel upward the horizontal tail — also called the stabilizer — and push the jet’s nose down.
Boeing’s bulletin laid out a seemingly simple response: Hit a pair of cutoff switches to turn off electrical motor that moves the stabilizer, disabling the automatic system — known as the Maneuvering Characteristics Augmentation System, or MCAS. Then swivel the tail down manually by turning a large stabilizer trim wheel next to the pilot’s seat that connects mechanically to the tail via cables.
Boeing has publicly contended for five months that this simple procedure was all that was needed to save the airplane if MCAS was inadvertently activated.
In the test, the two European pilots in the 737 simulator set up a situation reflecting what happens when the pre-software fix MCAS is activated: They then followed the instructions Boeing recommended and, as airspeed increases, the forces on the control column and on the stabilizer wheel become increasingly strong.
After just a few minutes, with the plane still nose down, the Swedish 737 training pilot flying as Captain is exerting all his might to hold the control column, locking his upper arms around it. Meanwhile, on his right, the first officer tries vainly to turn the stabilizer wheel, barely able to budge it by the end.
If this had been a real flight, these two very competent 737 pilots would have been all but lost.
Boeing was wrong and arrogantly so.
The company did not want to halt flights.
Foreign flight cancellations brought the issue to a head and Trump suspended flights with Boeing howling.
Mike “Mish” Shedlock
To substantiate that what mark0f0 is pointing out…
It’s on the end all about keeping the financial turn over. Re-design was out of question because it would have opened the door for Airbus to deliver in to the holy home yard of Boeing – American Airlines & Southwest Airlines.
Even though the equivalent Airbus models are a tick more expensive in the initial purchase price… the new engines and in particular the new designed winglets and other aerodynamic refinements of the A320NEO giving the aircraft almost 20% better fuel economy… which is almost impossible to ignore in today’s airline market.
As a result, Boeing had not only to find a way to fix the new engines on the airframe… something they struggled with as we discussed already. Fixing new engines on the airframe alone would not have given them only approx 13% better fuel economy… no, they had also to work on the airfoil and winglets.
In detail on the edge of the wing the under pressure on the top and the over-pressure on the down side of the airfoil meet and compensate each other resulting in the wingtip vortex. Someone can imagine that the carrying over-pressure under the wing is slipping around the edge and so a part of the wing’s lift is getting lost in the outer section. In this way someone can imagine the winglets as an obstacle (fence) that prevents this “aerodynamic short-circuit”
By doing so, this winglets do not only increase the efficiency of the wing… they improve also the adling and make the wing more “peaceful”.
Well, until… the critical edge – the stall point. When the difference of the pressure between upper and lower side of the airfoil becomes too big – and this is the case of high Angle of Attack – then the air can snap over the winglet. This exact point is very difficult to simulate reliably.
So, how to handle this as a designer… deepen the winglet! But then the parasitic drag will eat up the aerodynamic advantage of the winglet. You will end up with a winglet that adds weight but gives you only miniscule fuel savings. As far as I remember Airbus had once that problem with an over-designed winglet.
So now, someone has to know that all this winglet shapes and designs are patented and so Boeing designed for the 737 a new type of wingtip device- the Split Scimitar Winglet to get even with Airbus on fuel savings without copying their design.
In total… certainly there in an indication that the time was too short and this new winglet might not be fully understood aerodynamically… yet. The extended 2.5 degrees of authority for the MCAS is certainly pointing to this and might be a result that this new Split Scimitar Winglet gave the wing in reality a behavior under extreme AoA that was not anticipated and were not in line with the numeric simulations – additionally to all the other issues that has been pointed out before.
One thing no one has brought up (perhaps I missed it) is to what degree the FAA is to blame. Didn’t they have to approve the plane? Not rhetoric, I’m just asking.
Another point, more important. I was told by an engineer that there are 1/4th fewer employed engineers than there were 10 years ago. His midsized company had opened 6 offices in India and China in the past 20 years, not a single one in the US.
If there were 1/4th fewer MDs would you conclude
A) hey, people must be alot more healthy
B) Something is seriously wrong with the US economy at a fundamental level.
At age 58 he was the youngest engineer in his office. One sees very few older and more experienced engineers, they usually get laid off and are replaced by outsourcing and H1Bs. The result is that the overall quality of engineers in many fields is not what it used to be.
Younger engineers tend to write computer code to arrive at a more or less correct solution by trial and error, which can be a disaster if you don’t have a good knowledge of the problem at hand.
Obviously the computer models Boeing made indicated there was a problem, otherwise there wouldn’t have been a software ‘fix’ to it. Also obviously, they didn’t understand the problem.
I expect poor engineering will be a bigger and bigger problem for the US in the coming years.
Well, as far as I recall… investigations revealed that the FAA had a bit of work overload and outsourced the approval process of the 737MAX’s MCAS system to…. no joke… Boeing.
Actually the aerodynamic problem was discovered to be far more severe than anticipated in the computer modelling by actual flight testing. Which basically tells us that the computer simulations were wrong. MCAS, and its 2.5 degrees of authority was dramatically beyond the 0.6 degrees of authority documented in the design documentation that was used to obtain FAA approval.
The problem was well understood through flight testing, but then they proceeded to try to ‘fix’ the problem with a very haphazardly implemented computer system (to wit: MCAS) rather than an expensive re-design to address the root cause, or at the very least, a very robust MCAS system.
I agree that engineering in the US has issues. With the advent of the concept that everyone that pays the tuition deserves to graduate, combined with grade inflation, in my opinion, the quality of engineers in the US has been eroding for a long time.
As far as government regulation goes, there is no way that government regulation is going to solve this kind of a problem. If anything, it caused it, because airlines could say “well, the FAA approved it, so it must be OK”. The military tests the planes they buy extensively. The big airlines should do the same, and not just rely on FAA certification.
Good point.
Thank you to Gregory and the other highly qualified individuals who came forward with their stories and put their name and staked their personal reputation on helping to bring the truth to light. I am sure their are a lot of fine people and engineers at Boeing and when you get that large, every action you do becomes one of critical importance for the survival of the group. But big mistakes were made. Without pointing any fingers let me just say that I do not want to fly in an airplane that has any bad flight characteristics, (especially ones that are brought on with design changes), and software changes are added to attempt to correct those problems. Basic flight and aerodynamic principals have been violated here. That is unacceptable to me and should also be unacceptable to every aircraft manufacturer on the planet.
It’s easy to criticize with hindsight. It definitely looks like Boeing messed up here, but I don’t think it’s fair just to chalk it up to evil corporate greed. The reality is that a lot of airlines were really enthusiastic about getting upgrades to the 737s, which had become such a workhorse of the industry. Airlines love the idea of greater range and fuel efficiency without having to retrain or re-tool.
If anything, Boeing is guilty of being too eager to give customers what they wanted. If the software had been better designed maybe we wouldn’t even be talking about the 737 MAX problems right now and Boeing’s customers would be happily flying their new fleets.
Profit above all else. Sounds like they tried redesigning the wheel. Airplanes falling out of the sky, exploding cars, etc dare ask what’s next?
Hi everyone! Aviation enthusiast from Europe here. I am humbled by some many pros’ around.
From Europe, this entire Boeing mess looks like a Cold War-era caricature of greedy corporate America. It would be laughable if it were not for the loss of lives.
What baffles me the most in all of this is not even the ”new” design, the obsession with keeping an outdated airframe — albeit it was a perfect design for the era it was rolled out, when airport hardware was limited; or even the MCAS.
No, what baffles me is the fact the 737, despite going back to the drawing board for its MAX version, was still equipped with only two probes/sensors, even though this caused loss of hull in the past (a flight in Latin America, in the 1990s maybe? I can’t recall). With a third sensor/probe, the MCAS could choose to follow the two probes singing the same song, and ignore the one out of tune. Even better: if all three were to give different info’, the MCAS could shut-down, and some alarm/hint could be provided to the crew.
As for the software itself, Airbus has made similar mistakes in the past. Boeing could have learned from it. Especially since they were never last at bragging automation were terrible, and that’s why people should trust good old Boeing designs.
At least the people who designed that mess, as well as those who approved, work for a US company based in the US. If COMAC (China) teams were to make such a mess, quite a few would face capital punishment.
AoA measurement used to be just informational, ie: it didn’t actually feed any flight control hardware. So there wasn’t a great reason to have a lot of redundancy, aside from making the airplane suitably reliable for dispatch. If a few steam gauge dials on the airplane randomly had a few fluctuations, that was no big deal.
Things went off the rails when they started feeding the AoA instruments into computers, and actually controlling the airplane based on such instruments. ala MCAS. That’s when they needed to go to a robust triple redundant fault tolerant system, but out of a desire to “be cheap”, didn’t.
That’s precisely my point. And I’m pretty sure adding one AoA would not have cost that much, especially relative to the price of the green livery. I am also convinced they had room to had one. It simply baffles me they chose to go with only two…
Good information posted here from people who actually fly and work on these planes. It’s a shame that they could see the problems, and then Boeing sweeps them under the rug.
That’s how it works in every larger organization in The West these days. It’s the only way financialization and rabid overregulation can ever end up: Self dealing incompetents in charge of everything, faced with very little, if any, threat of being routed around by more competent competitors.
Boeing is focused on profit above all else, and unfortunately is not the first or only company to abandon moral and social responsibilities in favor of unbridled greed. History will undoubtedly label this as the age of Corporatism. The frustrating thing is that BA is one of the most subsidized companies in the US given its near monopoly status as a military supplier. Is there no reasonable limit to growth and profit?. It’s sad (and criminal) that Boeing would cut corners and deliberately (IMO) put passenger safety at risk. I appreciate the pilots who commented on this issue and wish more would step forward. They are the only ones who can temper Boeing’s greed in favor of more safe aircraft.
We still have the ExIm bank.
But the problem is the perverse incentives with regulation.
If you can somehow say it is still a 737, there is near zero cost with selling the plane. If it has to be recertified, and pilots retrained, it adds a billion dollars to the ultimate price tag for both Boeing and the Airlines.
The converse is they would have to continue to use older planes.
It happens with Automobiles. A new one loaded with all the mandated safety stuff is $30,000 (and you have obstructed view from the A pillars, and tap it and the repair is $1000, a little harder the airbags go off so it is totaled) so the insurance is high). So you buy a $3000 car without all the safety stuff – yes it is less safe – no side curtain airbags, and things are wearing out, but you can actually afford to buy it.
Regulation distorts the market worse than tariffs. We have consumer protection laws, so we get Chinese petfood with toxic melamine, and knockoff iPhone chargers that can catch fire, but they are cheaper! People want cheap! They want cheap airfares, which means keeping airplanes cheap.
do people want cheap or do they need cheap? a bit of both maybe? either way, blame the victims, eh?
If they don’t need cheap, they are labeled “rich,” and taxed until they need it too.
Age of Corporatism? I guess you think the state would run things much better. Like the old soviet union or China under Mao.
Read his last paragraph…
“Fascism should more appropriately be called Corporatism because it is a merger of state and corporate power”
― Benito Mussolini
‘Capitalism…is no longer the progressive force described by Marx’; the free market era ‘has been followed by a new one in which production is concentrated in vast syndicates and trusts which aim at monopoly control’. Giant multinational technology companies ‘freeze out other competition to forestall independent technological innovation’. Financial control ‘has passed from the industrialists themselves to a handful of banking conglomerates – the creation of a banking oligarch”
Imperialism: The Highest Stage of Capitalism
Lenin