Originally Posted by
Ripfree
Good point about the flaps. The weather was quite hot that morning, and the airport is over 7000 msl. The density altitude might have been quite high. I wonder if they pulled the flaps at around 8200 ft and stalled. Then recovered, climbed too steeply (mountains?) and stalled again. Pure speculation, I admit.
The airport is 7,657'.
The Lion Air report isn't final but a good amount of information has been released. Judging by the currently released information, there was nothing wrong with the MCAS system on the accident airplane. The failure was in an AoA vane/sender which fed the MCAS, and other systems, bad data.
Very little data out on the Ethiopian accident. The flightstats data, which is questionable due to poor coverage in the area, indicates that the flight never reached an altitude where the flaps would normally be retracted and the problem started almost immediately. MCAS is suppressed with the flaps extended.
If that holds then this wasn't an MCAS event. The rapid changes in vertical speed almost immediately after liftoff,
if correct, might indicate them trying to chase a bad airspeed indication (there are three separate IAS displays) either flying manually or on autoflight. If the airspeed displays differ by more than 4 knots you get "IAS DISAGREE" messages. Normal minimum autopilot engagement altitude is 800'.
We need a lot more information before we can say for sure what happened. So far, no evidence to suggest a connection between the two accidents.