Airline pilots on at least two U.S.-flown Boeing 737 Max 8 planes had reported that the automated system caused the aircraft’s nose to tilt down sharply and suddenly after take-off.
The pilots said they were able to recover quickly following the aggressive dive – descending as fast as 1,500 feet per minute – by disconnecting the autopilot.
However, the tilting problem did not appear related to the new automatic anti-stall system that’s suspected of contributing to the deadly Indonesia crash on that aircraft model in October.
The pilot reports were filed last year in a data base compiled by NASA. They are voluntary safety reports and do not publicly reveal the names of pilots, the airlines or the location of the incidents.
The Boeing Max 8 jet is now at the center of a growing global ban after more than 40 countries grounded the model following the second fatal crash in five months.
Two pilots in the U.S. reported that the Boeing 737 Max 8 suddenly tilted downwards as it was flying last year. The Ethiopian Airlines Max 8 plane that crashed on Sunday killing all 157 on board pictured above
The Boeing 737 Max 8 is the aircraft model that crashed in Ethiopia on Sunday and in Indonesia in October, marking two tragedies on the same model within five months
On Sunday an Ethiopian Airlines Max 8 crashed shortly after take-off killing all 157 on board. Five months earlier a Lion Air plane of the same model came down in Indonesia, claiming 189 lives.
On Wednesday afternoon Trump joined the outcry, grounding all of the model Max 8 and Max 9 planes ‘effective immediately’.
American Airlines and Southwest Airlines operate the 737 Max 8, and United Airlines flies a slightly larger version, the Max 9. All three carriers vouched for the safety of Max aircraft on Wednesday before Trump’s ban.
It’s unclear whether the two plane tilting reports led to any actions by the FAA or the pilots’ airlines.
In one report, an airline captain said that immediately after putting the plane on autopilot, the co-pilot called out ‘Descending,’ followed by an audio cockpit warning, ‘Don’t sink, don’t sink!’
The captain immediately disconnected the autopilot and resumed climbing.
‘With the concerns with the MAX 8 nose down stuff, we both thought it appropriate to bring it to your attention,’ the captain wrote. ‘Best guess from me is airspeed fluctuation’ due to a brief weather system overwhelming the plane’s automation.
Two U.S. pilots reported last year that they experienced issues with the Max 8 model saying it aggressively nosedived after take-off while on autopilot
The pilots said they were able to recover quickly following the aggressive dive by disconnecting the autopilot. The wreckage of the Ethiopian Airlines flight on Sunday pictured above
On Wednesday afternoon Trump joined more than 40 other countries, grounding all of the model Max 8 and Max 9 planes ‘effective immediately’
On another flight, the co-pilot said that seconds after engaging the autopilot, the nose pitched downward and the plane began descending at 1,200 to 1,500 feet (365 to 460 meters) per minute.
As in the other flight, the plane’s low-altitude-warning system issued an audio warning. The captain disconnected autopilot, and the plane began to climb.
The pilots talked it over later, ‘but can’t think of any reason the aircraft would pitch nose down so aggressively,’ the co-pilot recounted.
Preliminary information released by Indonesian investigators suggests they are looking at the possible role of the Max’s new automated anti-stall technology as a factor in a Lion Air crash in October shortly after takeoff from Jakarta.
Data indicates that the pilots struggled with repeated nose-down commands from the plane before it crashed into the Java Sea and killed 189 people.
However, that anti-stall system – called MCAS for its acronym – only activates if the autopilot is turned off, according to documents Boeing has shared with airlines and the FAA.
Though the two pilots filed their complaints last year, it’s not clear if anything came of their notes. The wreckage of the crashed Lion Air Flight that sunk into the Java sea pictured above on November 12, 2018
Rescue workers of crashed Lion Air flight JT610 carry a body bag off a boat at Tanjung Priok port in Jakarta, Indonesia, October 30, 2018
It’s still not clear just what sent those two Boeing 737 Max 8 flights down as the investigations continue
‘That’s not to say it’s not a problem,’ American Airlines pilot Dennis Tajer said of the incidents reported to NASA, ‘but it is not the MCAS. The autopilot has to be off for MCAS to kick in.’
A third pilot complained that Boeing had not explained changes to the plane’s automation to pilots.
‘I am left to wonder: what else don’t I know?’ the pilot wrote. ‘The Flight Manual is inadequate and almost criminally insufficient.’
The FAA declined to comment on the incidents that pilots reported, but said it was not aware of any verified reports of MCAS-related issues in the U.S.
American Airlines spokesman Ross Feinstein said the airline has received no reports from pilots about problems with the anti-stall technology. Southwest has said the same thing.
Leaders of the union representing United Airlines pilots, some of whom have flown the airline’s 14 Boeing 737 Max 9 jets since last May, said the airline has tracked 23,000 hours of flights and found no performance or mechanical problems.
The group, part of the Air Line Pilots Association, added, ‘It is imperative that pilots refrain from interacting with the media and adding to the sensationalism surrounding these incidents.’
Concern about the Max’s safety seemed to be abating but returned on Sunday following the horror Ethiopian Airlines crash.
Again, preliminary data appears to capture a brief and erratic flight. Investigators will analyze information from the planes so-called black boxes in hopes of understanding what caused the accident.