Quote Hyperveloce : Displaying hazardously misleading airspeed simultaneously on both pilots’ displays, coupled with the loss of stall warning or overspeed warning functions, must be Extremely Improbable.
This casts doubts on the way the certification process is thought and approved…There are fine engineers and test pilots at Airbus, but it seems that the problem lies « upstream » in the process. The FHA (functional Hasard Assessment) studies the failures analysis and their threat to the safety. This is studied in part 1309 of FAR 25, with an advisory circular (AC 1309) explaining how to understand and enforce the rules…If I understand it correctly, you must look closely at the different causes especially if the failure comes from false raw data, or bad transcription, or erroneous comparisons etc…That is the Failure Mode and Effects Analysis. It seems to me, but I shall be happy to be corrected, that this has not been done thoroughly as far as the « Pitots » and their information are concerned. It was understood (wrongly) that a single event (in this case the icing of the three probes) could not interfere, or pollute, all the channels downstream. Thus angle of attack measurements with perfecly health vanes is polluted by erroneous airspeed indications…The Perpignan crash of a 320, even if due to reckless decisions in a hasty test-flight, should have started a strong reaction from the BEA as far as the « Vote-validated inputs control » is concerned.
Many cases are not covered by the certification in those new generation airplanes, and apart from changing the probes (which should have been a prudent recommandation by the BEA…but no, it is Airbus and EASA who make the move ) it will be necessary to strenghten and question the certification process.
Will it be done without pressure from the pilots ? Rather unlikely, I fear.