Talk:China Northwest Airlines Flight 2119

The actual cause?
There is DEFINITELY NOT a flaps actuator per side, so it was not an actuator failure on one side or the other. There is one hydraulic motor, with a chain drive to a cross-shaft which contains universal joints to allow for wing flexing. There are several sensors monitoring the flaps, including a resolver at the outer end of the shaft on each wing, and a hydraulic brake mechanism, called the wing tip brake, at the outer end, which will hold the flaps STATIONARY if just about any failure, including cross-shaft fracture, occurs. That is, if the Flaps Computer is working correctly. Apparently it was, as it was returned to the manufacturer for test. Asymmetric flaps are usually catastrophic as they will overpower the normal roll control by the smaller ailerons, so prevention of asymmetry, the primary purpose of the Flaps Computer, is vital. As far as I know, there has never been a cross-shaft failure on the 146, but if there was on the crash aircraft, the flaps would have been locked in their extended position and the aircraft would have taken off.

It is most likely that the crew failed to check the "Takeoff Config" light which indicates that many systems, including flaps, have been set correctly for takeoff.

I joined the manufacturer of the flaps computer not long after this disaster, and one of my first tasks was to identify the problems with it. None of these related to it failing to perform the correct safety actions, rather it was causing flights to be delayed or cancelled due to false warnings, resulting from very poor work by its manifestly incompetent original designers, said to be a husband and wife team, somewhere in the USA. There were multiple errors, both analogue and digital. That was duly fixed, but I had to hand the redesign over to someone else as I was needed on the design of another project.

It was said that, following the verification of correct function of the Flaps Computer on the test rig at the factory, the Chinese executed the pilot by firing squad.

The truth will probably not be found from any official source. I am not sure how to obtain evidence to allow the truth to be told on Wikipedia.

Tiger99 (talk) 19:40, 23 May 2019 (UTC)


 * Thank you for this information. My father was in China on work business, when he was killed by this disaster. It should have been the start of his return journey home to U.K. 92.16.31.118 (talk) 15:58, 22 September 2023 (UTC)