Originally Posted by
JRBarrett
As would mine...
Which raises the question: “What post-replacement functional checks are called for (in the AMM), and what functional tests were actually performed after the replacement probe was installed?”
If the AMM calls for fitting a calibrated AOA protractor to the probe and fuselage to verify correlation between probe position and transmitted AOA data, and that was not done - either because of lack of time, lack of test equipment, or lack of training, it’s a serious problem.
I would hope that Lion Air maintenance didn’t just slap on a new probe, ignoring any required correlation tests on the assumption that the original probe itself was bad.
I believe others are asking the same.
'Ony Soerjo Wibowo, an air safety investigator for the Indonesian government, said that on the plane’s third-to-last flight, from the eastern Indonesian city of Manado to Bali, the plane, which was delivered to Lion Air in August, had recorded no airspeed data.' (cited in NY Times)
and Mr. Ony said that part of his investigation centered on why the plane had not been grounded by Lion Air, given that it had experienced multiple airspeed problems.“This is strange,” he said in an interview on Wednesday. “We found several events that we should investigate, but they didn’t report them.”
It's not clear who 'they' is that didn't report them. But, in looking at the leaked maintenance log, sure looks like some issues were not documented by prior crews. Don't know what condition the AoA sensor that replaced the alleged offending sensor was in either - probably whatever they had in store since it's the same PN as the NG uses (see #1418).