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).
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.
Chilean 737 Pilot
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.
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.
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.
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.
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