What is the architecture and logic of the 737 MAX stick-shake, stall warning system?
Information from discussions about the recent accident indicates that the combination of vane and stick-shaker are independent for each side of the aircraft; the respective side of the aircraft drives the same-side stick-shake.
Is this view confirmed by the wiring configuration; does the MAX installation differ from previous versions?
The accident view relates an ‘errant vane’ to the highest AoA, and thus is the reason for a ‘false’ stick-shake, but only on one side of the aircraft.
This view also implies that with serviceable vanes, then they track sufficiently close to give stick-shake on both control columns ‘near simultaneously’.
Conversely if an ‘errant vane’ is the lowest AoA, then in the event of real high AoA, only one stick-shake will operate (the higher, correct AoA).
Are these views correct; logical ?
(If so then there may be a ‘hole’ in the latest emergency trim checklist - what if the ‘errant’ vane gives a low AoA)