A Boeing 737 Max test pilot has been charged with obstructing US aviation safety regulators, according to the US Department of Justice, and faces up to 20 years in prison if convicted.
Former 737 Max chief technical pilot Mark Forkner, 49, of Texas, has been charged with "deceiving the Federal Aviation Administration's Aircraft Evaluation Group" (AEG) and committing fraud by misleading Boeing's airline customers into believing the 737 Max was a safe aircraft.
"Forkner allegedly abused his position of trust by intentionally withholding critical information about MCAS during the FAA evaluation and certification of the 737 MAX and from Boeing's US-based airline customers," said Assistant Attorney General Kenneth A Polite Jr of the Justice Department's Criminal Division in a statement.
The prosecutor claimed that Forkner had supplied the FAA with "materially false, inaccurate, and incomplete information" about MCAS, the Manoeuvering Characteristics Augmentation System. This, he said, was the root of the lack of documentation and understanding about MCAS which led to two fatal crashes.
In November 2016, the DoJ claims Forkner learned about an important change to MCAS and deliberately withheld that from the FAA's AEG, leading to safety approval reports not mentioning the software's presence.
Software that pilots didn't know about
MCAS is the 737 Max's controversial software-powered system responsible for the crashes of two 737 Maxes, killing 346 people. As chronicled here on The Register, MCAS was a software fix for the Max so the airliner's updated design could be "grandfathered" inside existing regulatory approvals for the elderly 737 design.
Boeing designed the 737 Max as a response to Airbus's competing A320neo model. To give its airliner comparable fuel economy with the Franco-German design, new engines were fitted to the 737 airframe. These changed its flying characteristics to the point where the FAA would not approve the Max for flight without requiring an expensive and lengthy certification process – or a software fix.
Thus MCAS introduced a software layer to the Max's (manual) flight control system. This included direct control of the aircraft's trim, setting how high or low its nose points during flight. Input to MCAS was made through a single angle-of-attack sensor, unlike in Airbus aircraft where three sensors' readings are used for redundancy.
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In the first Max crash, the sensor in use was giving false readings that prompted MCAS to apply full nose-down trim. Unaware of what the software was doing because MCAS had not been detailed in pilot manuals, the crew were unable to recover from the fatal dive. In the second crash the pilots applied Boeing's new counter-MCAS procedure – but everyone aboard died anyway because Boeing hadn't realised that no humans were strong enough to operate the manual trim override during situations where MCAS activated.
The FAA in effect alleges that had Forkner not covered up vital information about MCAS, neither crash would have happened.
Unlike his former employer, Forkner probably doesn't have $2.5bn to give to the DoJ's lawyers so the prosecution can magically disappear be resolved. He is due to appear in court today.
While new procedures and system redundancies have been introduced to mitigate MCAS, Boeing is still hoping airlines start placing more orders for the jets.
We asked Boeing to comment. ®