It took almost ten years, a time during which Boeing submitted their own internal report to the FAA which blamed the pilots of UA535 for the crash. The PCU design was such that it could affect any of the 737s in the air at any time between 1967 and 2002.
So thats the allowable timeframe then dozy? 10 years because boeing didn't fix it earlier.
But that's exactly what happened with the 737 hardovers, and the aircraft was left flying with a known fault for nearly ten years. The workaround there involved maintaining a higher approach speed, but it didn't solve the underlying problem and there was no guarantee that it would save the aircraft if the crew did not correctly diagnose the fault in time.
I agree that it took too long, want to repeat the same thing again?
What is there to investigate, it is known and proven that the alpha prot protection can lead to a complete loss of control due to faulty input. Fixing the aoa won't guarentee a faultless input. Thats a design flaw with respect to thinking that the protections will always be correct with regard to actual flightpath.
Maybe the solution is as easy as allowing the pilots to press the a/p disconnect button to override the protection.
Oh, sure. If they switched off ADRs following problems with AoA and then followed erroneous AoA information while cheerfully ignoring their attitude then they would be in real trouble.
the BUSS, fly the attitude!
That worked very well on AF447 no, it would be kind of hard to ignore what BUSS is telling you since it will be all over the PFD. In any case it won't make things easier since BUSS is all AOA related.
It resulted in how many deaths? Injuries? How much damage to property?
Now I have your attention, I'm not saying it is acceptable (whatever criteria we might use to define it) just that it was recoverable.
Quick thinking made it recoverable, let's not pretend that 12 degrees ND is anywhere in the normal flightregime.
I know that abnormal attitude law will trigger at 30 degrees ND, but would it in this case? And isn't 12 degrees ND already far outside the normal?
Maybe that's why we call it "Abnormal"?
You really believe that turning off 3 ADR's or 2 ADR's because of a stuck AOA vane is a proper solution? Whiping all airspeed data from one of the pilots, while in a dive!
Offcourse its abnormal, but the solution in itself seems to be a complete patch up which is abnormal.