Boeing is reportedly planning 737 MAX software upgrade
Boeing is reportedly considering a software upgrade for its 737 MAX family following the deadly crash of Lion Air Flight JT610 last month. The move comes after a preliminary report by Indonesian investigators, released just a few days ago, put the U.S. plane maker’s new anti-stall system at the center of the search for the cause of the accident.
Reuters, citing two sources briefed on Boeing’s proposal, said the aircraft manufacturer could launch the software update over the next six to eight weeks and that it would help address a situation the flight crew on the doomed 737 MAX 8 experienced.
Preliminary report issued by investigators on November 28th, indicated the pilots struggled with Boeing’s new automatic safety system, known as the Maneuvering Characteristics Augmentation System (MCAS) that was relying on a faulty angle of attack (AOA) sensor.
The MCAS, which is installed on all MAX planes, was repeatedly forcing the aircraft’s nose down, the factual details contained in the report reveal. Despite the pilots’ eight-minute battle trying to pull the nose back up, the 737 eventually went into nose dive.
In response to the October 29 crash, Boeing issued a safety bulletin for MAX operators, essentially directing them to follow existing flight crew procedures to address circumstances where there is erroneous input from an AOA sensor, due to which, the MCAS can cause an airplane to stall.
Pilots can prevent a stall in an event of a MCAS malfunction, an “over-reaction” known as a runaway, but it takes several steps that require specific knowledge of this precise case. The procedure can be counter-intuitive, as the New York Times explains.
The 737 MAX’s manual and training have come under scrutiny since the crash, as Indonesian authorities and U.S. pilot unions began reporting the MCAS was missing from their operating manuals, including in the Lion Air flight manual before the crash, Reuters indicated.
Boeing had said the procedure for dealing with a runaway situation does not differ from previous 737 models. Its safety bulletin advised operators to add information on MCAS to their flight manuals and a directive by the U.S. Federal Aviation Administration (FAA) has now made it mandatory.
Boeing has also said that cockpit procedures applied on the previous, Denpasar to Jakarta flight on October 28th, are already in place to tackle a malfunction of the anti-stall system. That flight experienced similar problems involving airspeed and altitude discrepancies, but landed safely after the pilots shut down the MCAS.
Why the fix now? Apparently, the aircraft manufacturer did not inform about the recent changes made to the automated anti-stall system in the 737 MAX manual. Reuters’ sources said the software update, although not a guarantee yet, would come as an “emergency measure” from Boeing and the FAA.
The update would, essentially, reset modifications to the anti-stall system: it would prevent it from continuously running until the plane hits its nose-down limit; the flight crew would be able to disengage the MCAS by trimming or adjusting settings in the opposite direction.
Although the KNKT says they have not yet determined if the anti-stall system was a “contributing“ factor, investigators are nevertheless planning to conduct tests in the Boeing engineering simulator configured for 737 MAX 8.
Indonesia’s director general of aviation, Polana Pramesti, told Reuters the agency planned to require pilots in Indonesia to be trained on simulators for the MAX series (instead of the computer-based conversion course for 737 pilots).
Meanwhile, Boeing continues to insist its 737s are safe (plural, as the aircraft in this this family, the MAX 7, 8, 9, and 10, are known to be very similar from an engineering standpoint; the FAA’s directive addresses both MAX 8 and 9 aircraft operators). So is the company covering its tracks with this proposed course of action or is it just due diligence?