Some interesting commentary and quotes in this article with highlights as follows:
“There are so many questions it’s sort of hard to put in one short statement,” said Roger Cox, a retired investigator with the U.S. National Transportation Safety Board and a former airline pilot.
“I would be very interested in knowing why one crew was able to cope with this stick shaker and trim anomaly, and why the next crew could not,” Cox said. “And I’d want to know why Lion Air could not or would not repair the problem.”
Cox cautioned that the flight data doesn’t tell the complete story. A cockpit recorder, which would help indicate what pilots were thinking about the malfunctions, hasn’t been recovered yet. And while the situation of conflicting instruments and alarms could have been confusing, he said he’d seen “a lot worse” in other investigations.
It’s reasonable to ask why the pilots didn’t shut off the trim system during the roughly 10 minutes they were assessing the plane’s behavior, he said. A decades-old emergency procedure teaches pilots to flip two switches to cut power to the motor that was pushing the nose down.
Even more vexing is why the plane exhibited the same malfunctions it had on the previous flight after it was supposedly repaired overnight. On a flight from Bali to Jakarta on Oct. 28, the plane’s stick shaker on the captain’s side of the plane was active for almost all of the roughly 90-minute flight and the angle of attack readings had the same errors, the data shows.
“Number one, why did the previous crew continue that flight?” Cox said. “Number two, did they or did they not make an appropriate write-up? The third question is how come you signed this thing off” to fly the next day.
https://www.bloombergquint.com/busin...ing#gs.WE5NkUQ