Originally Posted by
BobM2
There has been no mention of an AOA failure prior to its replacement on the evening prior to the crash. It was apparently replaced as trouble-shooting in response to repeated write-ups of Capt unreliable airspeed & altitude. This did not correct the unreliable airspeed & altitude, but rather introduced an additional failure on the last two flights.
Apparently, Ground Maintenance BITE testing showed that a faulty signal was received from the L AOA.
Satcom Guru (selected quotes)
"Prior to JT043, the AoA on the Captain (left) side had issues and was replaced. First, AOA signal fail was fixed by reset of the ADIRU. ADIRU is a combination of the Air Data Computer and the Inertial Reference Unit."
"On the next flight, AOA signal out of range is displayed and again ADIRU is saying AOA Signal Fail."
"The issues encountered in ET302 AoA vane must be taken into account with these two vanes apparently on Lion Air that malfunctioned. Is it a problem with the vanes or is it a problem in the data processing? What needs to be fixed? Was this just a string of bad luck and coincidence?"
Satcom Guru's post refers:
https://www.satcom.guru/2019/03/taki...aiting-on.html