Boeing’s efforts to keep 737 Next Generation and MAX training as similar as possible included limiting external discussion of the maneuvering characteristics augmentation system (MCAS) as early as 2013, as well as an aggressive lobbying effort to dissuade Lion Air from requiring simulator sessions for its pilots, new documents released by the manufacturer reveal.

The documents, comprising external and internal emails and internal instant message exchanges, underscore the priority Boeing placed on positioning the MAX as nearly the same as its predecessor, the 737 Next Generation (NG). They also offer some of the most compelling evidence yet that Boeing consciously chose less costly approaches over safer, more conservative ones during the MAX’s development.

Boeing determined early on that ensuring 737 pilots could transition to the MAX without simulator time would be a huge cost advantage when pitching the model to customers. It also realized that regulators could consider some of the MAX’s new features as too much to cover in computer-based training (CBT). The MCAS, a flight control law that commands automatic stabilizer movements in certain flight profiles, was chief among them.

A version of the MCAS was developed for the 767 tanker program, "but treated as analogous function, as a speed trim-type function,” a Boeing document summarizing a June 2013 MAX program meeting said. "If we emphasize MCAS is a new function there may be a greater certification and training impact.”

Boeing’s solution: refer to the MCAS externally as an addition to the 737 Speed Trim, not by its name. Boeing knew the approach might be questioned, so it sought input from its FAA-designated authorized representative (AR) "to ensure this strategy is acceptable” for certification.

"After speaking with the [AR], concurrence was provided that we can continue to use the MCAS nomenclature internally...while still considering MCAS to be an addition to the Speed Trim function,” the memo said. "This will allow us to maintain the MCAS nomenclature while not driving additional work due to training impacts and maintenance manual expansions."

The plan extended to keeping mention of the MCAS out of MAX pilot training materials. Its erroneous activation played key roles in two MAX accidents—Lion Air Flight 610 in October 2018 and Ethiopian Airlines Flight 302 in March 2019—that led regulators to ground the MAX in mid-March. The fleet remains grounded while Boeing addresses regulators’ concerns, including adding MCAS training and modifying the system’s logic.

Most pilots did not know the MCAS existed until after the Lion Air accident. Boeing has said repeatedly that it kept the MCAS out of manuals to simplify pilot training, and that an erroneous MCAS activation would be quickly diagnosed as a runaway stabilizer. The 2013 memo casts doubt on the former, and the two MAX accident sequences disproved the latter.

Boeing’s efforts to win approval for simulator-free MAX transition training succeeded with FAA approval in August 2016, nine months before Malindo Air become the first customer to take delivery of a MAX. But some MAX customers and regulators were not convinced that CBT, or Level B training, would be sufficient. Among them: Lion Air and Indonesia’s Directorate General of Civil Aviation (DGCA).

Lion Air was the first Asia-Pacific customer to order the MAX, and would be one of the model’s first operators. In June 2017, with its first delivery just days away, the airline was still developing its training curriculum, and simulator sessions were on the table. The airline's early entry-into-service status meant other MAX customers would be monitoring its progress and fleet-related decisions, including training.

"I would like to discuss what if any requirements beyond the Level B CBT the DGCA has required of you, or if your airline has determined any additional training is required,” a Boeing employee asked a Lion Air 737 training captain in early June 2017.

The captain replied that the airline “decided to give the transition pilot one simulator familiarization” in addition to CBT.

"There is absolutely no reason to require your pilots to require a MAX simulator to begin flying the MAX,” the Boeing employee replied. "Once the engines are started, there is only one difference between NG and MAX procedurally, and that is that there is no OFF position of the gear handle. Boeing does not understand what is to be gained by a three-hour simulator session, when the procedures are essentially the same.”

The Boeing employee then listed six regulators that “have all accepted the CBT requirement as the only training required” to transition to the MAX. “I’d be happy to share the operational difference training with you, to help you understand that a MAX simulator is both impractical and unnecessary for your pilots.”

In a subsequent email, the Boeing employee provided presentations on the MAX technical and operational differences for the Lion Air captain and his team. The Boeing employee also urged Lion Air to consider alternatives to simulator time, such as a flight-hour minimum in 737s or ensuring a pilot’s first MAX flight is always done alongside a pilot with MAX experience.

The following day, the Boeing employee followed up, again pitching alternatives to simulator sessions. “I am concerned that if [Lion Air] chooses to require a MAX simulator for its pilots beyond what all other regulators are requiring, that it will be creating a difficult and unnecessary training burden for your airline, as well as potentially establish a precedent in your region for other MAX customers,” the Boeing employee wrote.

Around the same time as the Lion Air exchange, two Boeing employees discussed the airline’s concerns in an instant-message chat.

“Now [Lion Air] might need a sim to fly the MAX, and maybe because of their own stupidity,” one Boeing employee wrote.

"WHAT THE…..!!!! But their sister airline”—Malindo—"is already flying it!” the second responded.

“I know. I’ve asked for a webex so we can [go] thru this with the DGCA. Not sure if this is Lion's fault or DGCA yet,” the first employee replied.

Boeing in a Jan. 9 statement issued a profuse apology for the document’s contents. "The language used in these communications, and some of the sentiments they express, are inconsistent with Boeing values, and the company is taking appropriate action in response,” Boeing said.

"We provided these documents to the FAA and Congress as a reflection of our commitment to transparency and cooperation with the authorities responsible for regulating and overseeing our industry. We welcome, and will fully support, any additional review the FAA believes is appropriate in connection with any of these matters, as well as the continued involvement of the relevant congressional committees with these issues.”

Boeing on Jan. 7 changed its position on the need for MAX simulator training. It is recommending all 737 pilots have simulator sessions before flying a MAX, including those who were flying the model before the 387-aircraft fleet was grounded. Its recommendation is based on simulator trials last month during which some line pilots did not follow checklists during emergency scenarios. Boeing is modifying several checklists as part of its MAX changes.