Originally Posted by
TTail
Now that it seems very likely that MCAS was involved in both the Lionair and the Ethiopean accidents, a sad irony emerges namely that the pilots (of the non-accident Lionair flight) who had the least knowledge of both the general MCAS issues and also of their own specific a/c issues, were the only ones who were able to handle the problem. Assuming warnings, cautions and lights were somewhat identical on all three flights - what was different? And what were the significant differences?
I posted this elsewhere this morning: IMO the main differences were the speed at which the trim switches were cut. It has become clear that manual control is not possible when the horizontal stabiliser is loaded by the elevator deflection, at airspeeds > 250kts. The only way to survive that scenario was to reduce the power, and cut the switches early enough. Can someone with the FDR readout of the earlier Lion Air flight confirm if this was what happened?
Edit: Ironically in a nose down condition, engine thrust may produce a pitch up force due to the underslung engines. This could have given some assistance at low speeds, but would not overcome the inability to move the stabiliser at high speeds.