The Boeing 737 MAX was initially certified in 2017 by the U.S. Federal Aviation Administration (FAA) and the European Union Aviation Safety Agency (EASA). Global regulators grounded the plane in 2019 following fatal crashes of Lion Air Flight 610 and Ethiopian Airlines Flight 302. Both crashes were linked to the Maneuvering Characteristics Augmentation System (MCAS), a new automatic flight control feature. Investigations into both crashes determined that Boeing and the FAA favored cost-saving solutions, which ultimately produced a flawed design of the MCAS instead. The FAA's Organization Designation Authorization program, allowing manufacturers to act on its behalf, was also questioned for weakening its oversight of Boeing.
Boeing wanted the FAA to certify the airplane as another version of the long-established 737; this would limit the need for additional training of pilots, a major cost saving for airline customers. During flight tests, however, Boeing discovered that the position and larger size of the engines tended to push up the airplane nose during certain maneuvers. To counter that tendency and ensure fleet commonality with the 737 family, Boeing added MCAS so the MAX would handle similar to earlier 737 versions. Boeing convinced the FAA that MCAS could not fail hazardously or catastrophically, and that existing procedures were effective in dealing with malfunctions. The MAX was exempted from certain newer safety requirements, saving Boeing billions of dollars in development costs. In February 2020, the US Justice Department (DOJ) investigated Boeing's hiding of information from the FAA, based on the content of internal emails. In January 2021, Boeing settled to pay over $2.5 billion after being charged with fraud in connections to the crashes. The settlement included $243.6 million criminal fine for defrauding the FAA when it won the approval for the 737 MAX, $1.77 billion as compensation for airline customers, and $500 million as compensation for family members of crash victims.
In June 2020, the U.S. Inspector General's report revealed that MCAS problems dated several years before the accidents. The FAA found several defects that Boeing deferred to fix, in violation of regulations. In September 2020, the House of Representatives concluded its investigation and cited numerous instances where Boeing dismissed employee concerns with MCAS, prioritized deadline and budget constraints over safety, and where it lacked transparency in disclosing essential information to the FAA. It further found that the assumption that simulator training would not be necessary had "diminished safety, minimized the value of pilot training, and inhibited technical design improvements".
In November 2020, the FAA announced that it had cleared the 737 MAX to return to service. Various system, maintenance and training requirements are stipulated, as well as design changes that must be implemented on each aircraft before the FAA issues an airworthiness certificate, without delegation to Boeing. Other major regulators worldwide are gradually following suit: In 2021, after two years of grounding, Transport Canada and EASA both cleared the MAX subject to additional requirements.
Initial certification
Type rating In the U.S., the MAX shares a compatible type rating throughout the Boeing 737 series. The impetus for Boeing to build the 737 MAX was serious competition from the Airbus A320neo, which was a threat to win a major order for aircraft from American Airlines, a traditional customer for Boeing airplanes. Boeing decided to update its 737, designed in the 1960s, rather than designing a clean sheet aircraft, which would have cost much more and taken years longer. Boeing's goal was to ensure the 737 MAX would not need a new type rating, which would require significant additional pilot training, adding unacceptably to the overall cost of the airplane for customers.
The 737 was first certified by the FAA in 1967. Like every new 737 model since then, the MAX has been approved partially with the original requirements and partially with more current regulations, enabling certain rules and requirements to be grandfathered in. Chief executive Dai Whittingham of the independent trade group UK Flight Safety Committee disputed the idea that the MAX was just another 737, saying, "It is a different body and aircraft but certifiers gave it the same type rating."
On May 15, 2019, during a senate hearing, FAA acting administrator Daniel Elwell defended their certification process of Boeing aircraft. Nonetheless, the FAA criticized Boeing for not mentioning the MCAS in the 737 MAX's manuals.
Crew manuals
Boeing considered MCAS part of the flight control system, based on the fundamental design philosophy of retaining commonality with the 737NG. In 2013, a Boeing meeting urged participants to consider MCAS (Maneuvering Characteristics Augmentation System) as a simple add-on to the existing stability function: "If we emphasize MCAS is a new function there may be greater certification and training impact". Boeing also played down the scope of MCAS to regulators. The company "never disclosed the revamp of MCAS to FAA officials involved in determining pilot training needs".
On March 30, 2016, Mark Forkner, then MAX's chief technical pilot, requested senior FAA officials to remove MCAS from the pilot's manual. Boeing had presented MCAS as being existing technology, but inquiries and certification authorities have raised doubts about its technology readiness. The officials had been briefed on the original version of MCAS but not that MCAS was being significantly overhauled. Because Boeing offered Southwest Airlines a $1-million-per-plane rebate if training was ultimately required, pressure on Boeing executives and engineers increased.
In 2017, as the airliner's five-year certification was nearly completed, Forkner wrote to an FAA official, "Delete MCAS". He then departed Boeing and joined Southwest Airlines in 2018. MCAS was left in the glossary of the 1,600-page flight manual.
Top Boeing officials believed MCAS operated only far beyond the normal flight envelope, and was unlikely to activate in normal flight. Boeing had also failed to answer questions raised by Canadian test pilots on behalf of Transport Canada about how the anti-stall system operated before the airplane was certified.
Most air regulatory agencies, including the FAA, Transport Canada and EASA, did not require specific training on MCAS. Brazil's national civil aviation agency "was one of the only civil aviation authorities to require specific training for the operation of the 737-8 Max". Pilots of the 737 Next Generation received an hour-long iPad lesson to fly on the MAX.
On November 6, 2018, after the Lion Air accident, Boeing published a service bulletin in which MCAS was mentioned as a "pitch trim system." In reference to the Lion Air accident, Boeing said the system could be triggered by erroneous angle of attack information when the aircraft is under manual control, and reminded pilots of various indications and effects that can result from this erroneous information. Only four days later, on November 10, 2018, Boeing acknowledged the existence of MCAS in a message to operators.
From November 2018 to March 2019, months between the accidents, the FAA Aviation Safety Reporting System received numerous U.S. pilot complaints of the aircraft's unexpected behaviors, and how the crew manual lacked any description of the system.
On January 9, 2020, Boeing turned over a hundred internal messages of employees criticizing the FAA and the 737 MAX's development. The majority of them being made before either crash. Some messages read that Boeing was trying to get airlines and regulators, including Lion Air, to avoid simulator training, as well as general frustration with Boeing management.
The FAA stated that "the tone and content of some of the language contained in the documents is disappointing," while Boeing said that the messages "do not reflect the company we are and need to be, and they are completely unacceptable."
Simulator training
On May 17, 2019, after discovering 737 MAX flight simulators could not adequately replicate MCAS activation, Boeing corrected the software to improve the force feedback of the manual trim wheel and to ensure realism. This led to a debate on whether simulator training is a prerequisite prior to the aircraft's eventual return to service. On May 31, Boeing proposed that simulator training for pilots flying on the 737 MAX would not be mandatory. Computer training is deemed sufficient by the FAA Flight Standardization Board, the US Airline Pilots Association and Southwest Airlines pilots, but Transport Canada and American Airlines urged use of simulators.
On June 19, in a testimony before the U.S. House Committee on Transportation and Infrastructure, Chesley Sullenberger advocated for simulator training. "Pilots need to have first-hand experience with the crash scenarios and its conflicting indications before flying with passengers and crew." The "differences training" is the subject of worry by senior industry training experts. Textron-owned simulator maker TRU Simulation + Training anticipated a transition course but not mandatory simulator sessions in minimum standards being developed by Boeing and the FAA.
On July 24, Boeing indicated that some regulatory agencies may mandate simulator training before return to service, and also expected some airlines to require simulator sessions even if these are not mandated.
On August 22, 2019, the FAA announced that it would invite pilots from around the world, intended to be a representative cross-section of "ordinary" 737 pilots, to participate in simulator tests as part of the recertification process, at a date to be determined. The evaluation group sessions are one of the final steps in the validation of flight-control computer software updates and will involve around 30 pilots, including some first officers with multi-crew pilot licenses that emphasize simulator experience rather than flight hours. The FAA hopes that the feedback from pilots with more varied experience will enable it to determine more effective training standards for the aircraft.
On January 7, 2020, Boeing reversed its position and now recommends that pilots receive training in a MAX flight simulator. The FAA will conduct tests using pilots from US and foreign airlines, to determine flight training and emergency procedures. National aviation authorities will consider Boeing's recommendation but will also rely on the outcome of tests and expert opinions. According to The Seattle Times as of this policy reversal, only 34 full-motion 737 MAX flight simulators have been deployed worldwide. The FAA agrees with Boeing on requiring simulator training for pilots, as the MAX returns to service.
Rejected improvements During the development of the MAX, some systems that could have improved situation awareness related to the accidents did not make it. Boeing also successfully appealed safety concerns raised by FAA safety specialists about the separation of cables into different zones of the aircraft, to avoid failures due to a common cause. The appeal raised doubts about the independence of the FAA.
According to The Seattle Times, Boeing convinced the FAA, during MAX certification in 2014, to grant exceptions to federal crew alerting regulations, specifically relating to the "suppression of false, unnecessary" information. DeFazio, Chair of the House Committee on Transportation and Infrastructure, said that Boeing considered adding a more robust alerting system for MCAS but finally shelved the idea. FAA exempted Boeing from installing an Engine Indicating and Crew Alerting System (EICAS).