I’m Not Sure that Boeing Can Make Aircraft Anymore

It now appears that the Ethiopian Air pilots followed Boeing’s protocols for dealing with a runaway trim and that the system still drove the aircraft into the ground:

The pilots of Ethiopia Airlines Flight 302 apparently followed the proper steps to shut down an errant flight control system as they struggled to regain control of the 737 MAX aircraft shortly after takeoff. But according to multiple reports, data from the ill-fated aircraft’s flight recorder revealed that the anti-stall feature of the aircraft’s Maneuvering Characteristics Augmentation System (MCAS) was triggered at least three times—and at least one time after the pilots followed the correct steps to shut it down.

Both Reuters and The Wall Street Journal report that the air crew followed procedures laid out by Boeing following the crash of a Lion Air 737 MAX in October, according to officials briefed on the initial findings of the investigation. But the pilots failed to regain control of the system, and the MCAS was reactivated again—triggering yet another automated correction of the aircraft’s stabilizers that would have pushed the nose of the plane down.


To prevent the MCAS from continually pushing the nose down in the event of bad sensor data or some other software failure, Boeing instructed pilots to deactivate the system using procedures already in place for dealing with runaway stabilizer control systems in other 737 aircraft—flipping two stabilizer trim “cutout” switches to the “cutout” position. Failure to do so could result in the system pushing the stabilizers to their movement limit—putting the aircraft into a steep dive. The pilots of the Ethiopian Airlines flight did flip the cutout switches, and they cranked the controls to attempt to regain positive stabilizer control. But they continued to have difficulty controlling the aircraft.

It is not clear at this point whether the pilots purposely reactivated the MCAS’ stabilizer control or if the software reactivated on its own after shutdown. While a Wall Street Journal source said that it appeared the pilots turned the system back on in hopes of regaining control over the stabilizers, Reuters reports that the software may have reactivated without human intervention, and further investigations of that possibility are ongoing.


If the air crew did follow Boeing’s instructions on recovering from an MCAS system failure, the information emerging from the Ethiopian Airlines crash investigation raises more questions about Boeing’s response to the Lion Air crash five months earlier and the Federal Aviation Administration’s review of that response.

Every time we get more information on MCAS and the crashes, it just gets worse and worse, and now it seems that there are some very basic problems on their factory floor, as the Air Force has paused deliveries of the KC-46 tanker because of problems with foreign objects being found in delivered aircraft.

Seriously, that is aircraft building 101:  Don’t leave sh%$ in a plane when it rolls off the production line:

The Air Force has stopped accepting deliveries of Boeing Co.’s new refueling tanker aircraft for the second time in a month because of debris found in closed compartments, according to Secretary Heather Wilson.

The halt in deliveries of the KC-46A Pegasus is the latest issue to plague the $44 billion effort to create the first U.S.-built flying gas station for the Pentagon’s fleet since the KC-10A Extender in 1981.

“We actually stopped again,” Wilson said Tuesday at a House Armed Services Committee hearing. Wilson told lawmakers that the Air Force found “foreign object debris” in closed compartments of the aircraft.

Elaborating on the trash left behind by workers, Wilson told the House Appropriations Defense subcommittee later in the day that it was a “manufacturing discipline” issue on the assembly line where “we saw a breakdown.”

“If you drop a wrench you have to find a wrench,” she said. “You have to wipe down surfaces so you don’t have pieces of aluminum that over time get in the midst of things and cause serious problems.”

Boeing has lost its way.

It has been relentlessly chasing MBA-think and over-inflated executive compensation, and making aircraft has become secondary.

I so hope that I am flying Airbus to Portland in June.


  1. marku says:

    More techincal data over at Leeham News, which has beenon top of this since the start.

    It appears that at the speed they were flying, human force can' override the force on the elevator. Hence, to move the elevator back up they had to turn on electric trim. Which turned MCAS back on
    Boeing seems not to have tested their solution tree to the MCAS Eff-up. Which is why MCAS as able to kill again.

  2. Anonymous says:

    Boeing sold the mcas warning feature to monitor the angle of attack sensors in disagreement as an optional upgrade. This may have prevented both accidents. They sold it just like a consumer cable TV package.

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