Re:'Passengers are afraid of this airplane': How Boeing is h...
by madeofpalk on Wednesday April 24, 2019 @10:25AM
(#19738622)
> (1) Add a third AoA sensor, with voting among them.
Interestingly enough, poor software 'voting' was one of the things that lead to Qantas' A330 suddenly diving downwards mid-flight a few years back https://en.wikipedia.org/wiki/Qantas_Flight_72
> In the usual case, when all three AOA values were valid and consistent, the average value of AOA 1 and AOA 2 was used by the FCPCs for their computations. If either AOA 1 or AOA 2 significantly deviated from the other two values, the FCPCs used a memorised value for 1.2 seconds. The FCPC algorithm was very effective, but it could not correctly manage a scenario where there were multiple spikes in either AOA 1 or AOA 2 that were 1.2 seconds apart.
They never did actually determine why the sensor data was corrupted.
Interestingly enough, poor software 'voting' was one of the things that lead to Qantas' A330 suddenly diving downwards mid-flight a few years back https://en.wikipedia.org/wiki/Qantas_Flight_72
> In the usual case, when all three AOA values were valid and consistent, the average value of AOA 1 and AOA 2 was used by the FCPCs for their computations. If either AOA 1 or AOA 2 significantly deviated from the other two values, the FCPCs used a memorised value for 1.2 seconds. The FCPC algorithm was very effective, but it could not correctly manage a scenario where there were multiple spikes in either AOA 1 or AOA 2 that were 1.2 seconds apart.
They never did actually determine why the sensor data was corrupted.