A Boeing 737 MAX 7 aircraft lands during an evaluation flight at Boeing Field in Seattle, Washington, on Sept. 30, 2020.LINDSEY WASSON/Reuters
Brian A. Barsky is Professor of the Graduate School in the College of Engineering at the University of California, Berkeley, where he is a Warren and Marjorie Minner Faculty Fellow in Engineering Ethics and Professional/Social Responsibility and Emeritus Professor of Computer Science. He has been teaching a course since August, 2019, at UC Berkeley on “Boeing 737 MAX: Money, Machines, and Morals in Conflict.” He is writing from Montreal.
Less than a week after Omar Alghabra was appointed Minister of Transport, he has put the safety of the flying public in jeopardy by returning the unsafe Boeing 737 Max to Canadian airspace. Could this be related to the fact that Air Canada and WestJet have dozens of these airplanes in their fleets and more on order? Mr. Alghabra’s assertion that all safety issues have been addressed rings hollows because it misses the elephant-sized jet engine in the room: The Boeing 737 Max has ill-positioned engines, situated too far forward on the wings, a design that causes unstable flight.
More precisely, this engine configuration effectively behaves like an extra forward wing and creates unwanted additional lift. The lift causes the airplane to rotate about its centre of gravity, located far behind the engines. This rotation results in the nose pitching up, impeding level flight. This can lead to an aerodynamic stall, in which the airplane can no longer stay aloft.
Boeing’s newest model, the 737 Max, suffered two fatal crashes with similar characteristics within five months of each other during its short 22 months of commercial flight before it was grounded worldwide in March, 2019. The crash rate (crashes per million flight miles) of the 737 Max is 44 times higher than that of the 737-600/700/800/900 series.
Transport Canada announced that it is imposing “unique Canadian” measures in addition to those recently mandated by the U.S. Federal Aviation Administration (FAA) for its recertification of the 737 Max. Canada’s measures include enforcing safety standards for physical separation of wiring, putting colour caps on circuit breakers, requiring that a vital warning light not be an extra-cost option, ensuring maintenance, increasing training for the flight crew and updating software. Although such improvements are laudable, this airplane cannot be rendered safe merely by remedying some glaring issues which never should have escaped notice in the first place.
The software in question is the Manoeuvring Characteristics Augmentation System, known as MCAS. The raison d’être of MCAS is to counteract the tendency of the 737 Max to pitch up. The system was developed to activate automatically and control flight if it detects that the wing is tilted too much relative to the airflow direction (known as angle of attack, or AOA).
It is indeed mind boggling that MCAS was developed to take input from only a single AOA sensor, even though there are two on board – one on either side of the nose. These angle of attack sensors are just little weather vanes, which can be easily become faulty. MCAS did not validate the basic plausibility of incoming data before it wrested control away from the pilots in both crashes.
But more important is to question why MCAS should exist at all on the 737 Max. No other commercial passenger airplane has similar software; rather, they fly level without it because their physical designs adhere to fundamental aerodynamic principles.
The FAA ungrounding directives retain MCAS, but with several modifications. It will now take input from both onboard sensors. If a fault is detected, such as a discrepancy between the two sensors, MCAS will be shut down for the entire remainder of the flight. Unfortunately, the directives stop short of requiring a third sensor which could provide valuable information in the case of disparate sensor readings. The competing Airbus A320neo has a third sensor in the tail of the airplane, even though Airbus does not use a dangerous software system like MCAS. Note that with such a shutdown there would then be no MCAS available to assist the pilots should a pitch-up situation arise.
Because accidents are often the result of multiple simultaneous problems, some other failure occurring while MCAS is not operating could spell disaster.
Although Boeing claims pitch-up rarely occurs, the FAA has not released information to substantiate this assertion, raising questions about the existence of data or the possibility that the assertion is an exaggeration and that unstable flight could actually be a more frequent occurrence.
The ungrounding decision of the FAA is based on secret data and testing. Flyers Rights, the largest nonprofit airline consumer organization, filed a U.S. Federal Freedom of Information Act request. However, the FAA’s arrogant response was to provide documents from Boeing that have page after page completely blacked out.
When Transport Canada originally certified the 737 Max in 2017, it did so by relying on information provided by the FAA. But that information failed to disclose the existence of MCAS which subsequently figured prominently in both crashes. Transport Canada had put its trust in the FAA, but that turned out to be dead wrong, costing 346 lives.
Unfortunately, the FAA is far from the objective watchdog that it should be. It surrendered its regulatory authority to the business world in what economists call “regulatory capture.” Specifically, the FAA relinquished direct oversight of much of the certification process to Boeing management in 2005 under the Organization Designation Authorization (ODA) program.
Boeing influenced the FAA to certify the 737 Max in 2017, even though the agency identified a variety of legacy physical design details that did not comply with its current safety regulations and despite the airplane having an aerodynamically unstable design.
The first tragedy occurred on Oct. 29, 2018, when Lion Air flight 610 crashed into the Java Sea 13 minutes after takeoff from Jakarta, killing all 189 passengers and crew on board.
Then on March 10, 2019, my friend’s granddaughter was among the victims of the second tragedy when Ethiopian Airlines Flight 302 crashed six minutes after takeoff from Addis Ababa, killing all 157 people on board, including 18 Canadians.
It quickly became apparent that this second tragedy bore similar characteristics to those of the first crash. Consequently, by Tuesday, March 12, at least 40 countries in Europe and Asia grounded the 737 Max, but Canada and the U.S. were conspicuously absent from the list.
Instead, that morning, Dennis A. Muilenburg, then CEO of Boeing, one of America’s largest exporters, was personally expressing his confidence in the safety of the fleet in a telephone call with then president Donald Trump.
After Marc Garneau, the Canadian Minister of Transport at the time, announced Canada’s grounding on Wednesday morning, and showed that the vertical profile of this doomed flight was similar to that of the earlier crash in Indonesia, the obdurate U.S. FAA reversed course with Mr. Trump’s grandstanding announcement of the U.S. grounding.
Jim Marko, then a manager in aircraft integration and safety assessment at Transport Canada’s Civil Aviation department with 30 years of experience, opined, “The only way I see moving forward at this point, is that MCAS has to go.” But Nicholas Robinson, Director General of Transport Canada was dismissive of his position.
When I met in Jakarta with the head of the Aviation Accident Investigation Subcommittee of Indonesia’s National Transportation Safety Committee (known as KNKT) about the Lion Air crash, I was amazed when I learnt the pilots of that doomed flight had never even been told about the existence of MCAS on their airplane.
Incredibly, this was not an oversight but a deliberate ploy to hide this information. The explanation of MCAS was removed from the pilot’s manual as a result of Boeing’s chief technical pilot for the 737 Max, Mark Forkner, manipulating the FAA, his former employer. He boasted in an e-mail, “Looks like my Jedi mind trick worked again!”
Moreover, Boeing did not provide the FAA with an accurate specification of the actual MCAS installed in the 737 Max airplanes. The FAA had a description of an earlier design, but Boeing implemented a more powerful and dangerous version, which could activate at high speed and not only at low speed, make large adjustments to the horizontal trim and deploy without regard to g-force (acceleration) data.
This deception led to criminal fraud charges for which Boeing agreed earlier this month to pay US$2.51 billion as part of a settlement agreement with the U.S. Department of Justice.
The FAA had pandered to Boeing by classifying the Max in the same “type rating” as previous 737 aircraft. This critical ruling allowed pilots who had flown any of the legacy 737 models to fly the Max. Pilots would not need to undergo any flight simulator training for the Max. The FAA approved Boeing’s request that training on an iPad for about an hour would suffice. Thus, pilots could fly the Max with no knowledge of MCAS. Boeing even offered airlines a rebate of US$1-million per airplane if 737 Max simulator training were to be needed.
Boeing’s disastrous short-term focus on the bottom line, prioritizing profits over safety, forms the genesis of the poor design of the 737 Max. The dismantling of Boeing’s once-great engineering culture began with its 1997 merger with McDonnell Douglas.
The tragic story of the 737 Max starts in 2011, with Boeing scrambling to develop an airplane to compete with the Airbus A320neo. Creating a new modern aircraft requires a design and development process costing billions of dollars and taking many years, involving extensive approvals from the FAA, and simulator training and certification for pilots.
Boeing management decided to short-circuit the process by reconfiguring one of its existing aircraft, the 737. It is the oldest aircraft series still in commercial passenger service, launched in 1965, before Hockey Night in Canada was broadcast in colour. Back then, Boeing designed an aircraft with a built-in folding stairway to the tarmac and direct access to stowed luggage from the ground. The result was, and remains today, an airframe that sits lower to the ground than other commercial passenger jets do.
This legacy design is a critical problem for the 737 Max. To compete with the fuel-efficient A320neo, the Max uses modern high-efficiency engines with larger diameter than on previous 737 models. But this is problematic because the low-to-the-ground design lacks sufficient ground clearance to allow the larger engines to fit under the wings. To circumvent this issue, Boeing positioned the engines for the Max forward and higher on the wing, which engenders the pitch-up problem.
However, absent from the changes mandated by the FAA and Transport Canada is any requirement to modify the aerodynamic design to solve this intrinsic instability. Also, the FAA should be forthcoming and provide full and complete information so that independent subject matter experts can objectively evaluate the safety of this airplane. Transport Canada should address these critical issues to ensure that the safety of the Boeing 737 Max is commensurate with the other commercial passenger airplanes that share the Canadian skies.
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