NASA compiles a database of voluntary pilot reports (ASRS) and this database contains at least 2 reports by US pilots who experienced problems with the auto-pilot keeping the nose down on B737 Max 8 & 9 aircraft. It is highly unlikely that the FAA does not factor these in.
Canada today also grounded the aircraft. However they have stated that had studied satellite data and found similarities between the Ethiopian and the Lion Air take-offs.
The ASRS database is the world’s largest repository of voluntary, confidential safety information provided by aviation’s frontline personnel, including pilots, controllers, mechanics, flight attendants, and dispatchers. The database provides a foundation for specific products and subsequent research addressing a variety of aviation safety issues.
The US reports are about the autopilot rather than the anti-stall system. The US experiences are reported in PhysOrg.
Airline pilots on at least two U.S. flights have reported that an automated system seemed to cause their Boeing 737 Max planes to tilt down suddenly. The pilots said that soon after engaging the autopilot on Boeing 737 Max 8 planes, the nose tilted down sharply. In both cases, they recovered quickly after disconnecting the autopilot..
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The pilot reports were filed last year in a data base compiled by NASA. ……….. It was unclear whether the accounts 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.
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. “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.”
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It is time for Boeing and the FAA, but primarily for Boeing, to ground the aircrafts till they have sorted out the clearly deficient software.
Boeing share price is in a decline if not yet in a nose-dive.
Tags: Boeing, Boeing 737 Max 8
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