Originally Posted by
Australopithecus
AoA disagree messages might be useful in some scenarios, but when presented with a sole stick shaker on take-off it would be pretty obvious five seconds later that if you were still climbing normally that the alpha vane was providing bad information. (And hence in disagreement with both the wing and the other vane). A useful thing AoA disagree could have done was disable the MCAS, but of course it wasn’t so designed
Originally Posted by
pilotmike
Seriously? A 5 second snap judgement that an aircraft can't be approaching a stall because it is climbing?
Originally Posted by
Australopithecus
Don't you recognise a general statement of concept when you see it? Take as long as you need Mike. If you have the correct attitude, planned thrust and the planned flaps you should be able to assess your energy and lift state pretty quickly. These aircraft come with FPV, so if the speed, theta and gamma values are normal where's the mystery? AoA disagree on a duplex instillation on the other hand does not tell you anything about your proximity to a stall.
The way you wrote that I think I am on Mikes side, and your snide reply doesn't help. AF447 was climbing very well while they got closer and closer to stalling, so apparently not that obvious in 5 seconds. It would not have been "useful", it should have been required to have two inputs for MCAS.
The fact that you can't cancel all the erroneous warnings alone is already enough reason the NG should not been certified.