Originally Posted by
PEI_3721
Ian W, #2055, you, and others assume that the vane is the source of error; this may be based on the FDR readout, but without knowing the origin of the FDR value - vane, digital bus, output of a computation, there could be alternative sources for the error.
Thus consider alternatives for erroneous AoA, specific to the 737 Max - wiring, interaction, software.
Boeing 737 Max Software Fixes Due to Lion Air Crash Delayed
If a viable alternative is established or even if only likely (difficult to find a intermittent fault amongst the wreckage), then all Max aircraft will require inspection - if only we know what to look for.
Well true.
But it is obviously not happening in the worldwide fleet of NG and other 737 or failures would be too common to even think of using a single source of data.
So what in the chain of electronics from the vane to the ADIRUs and MCAS is different in the MAX - something has increased the AoA sensor failure rate.