Originally Posted by
Water pilot
Somehow, from the information provided by the aircrew, the technicians were able to figure out that they had a malfunctioning AOA indicator -- which was replaced. The second one failed as well, for reasons that are not known (to us). So from a maintenance point of view, the reports were adequate.
Expecting line technicians in Ethiopia to discover a critical design flaw in a system that Boeing was keeping at least semi-secret is asking too much, in my opinion. Put yourself in the shoes even of a tech working in America, even if you had intimations that the shiny new 737 MAX was completely %$@!$ in rare circumstances and the entire fleet should immediately be grounded, would you pursue that line of inquiry? You have your 18 months of training from a vocational/tech school and you are going up against all of the PhDs at Boeing? I think not...
Sorry, but you got the sequence of events wrong. This has nothing whatsoever to do with the Ethiopian flight, but with the last two Lion Air flights, the one before the accident, and the accident Lion Air flight. Lion Air is Indonesian not Ethiopian.
The AoA was replaced before the flight with the Lion Air crew that managed to save the aircraft. And that Lion Air crew that saved the plane didn't report the stick shaker issue. After that flight the engineers/technicians/mechanics at Lion Air (Indonesia) didn't test the recently replaced AoA vane for issues. If the stick shaker would have been reported by the pilots after that flight, engineers/technicians/mechanics might have checked the AoA vane and may have fixed the problem before the accident Lion Air flight (Indonesian).
I didn't expect the engineers/technicians/mechanics at Lion Air (Indonesia) to find any critical flaw about MCAS or the MAX. But just as they replaced the AoA sensor once, at the very least they could replace it a second time. Since the AoA issue and the stick shaker simptom started when they replaced the AoA sensor, replacing it again might have fixed the issue and the Lion Air (Indonesian) accident might not have happened.
None of this assumes or requires any knowledge about MCAS from any of the Lion Air employees. If that's still not clear, maybe somebody else could try to explain it better than me, because I give up.