Originally Posted by
Green-dot
As an example, such was the case when the B737 rudder PCU servo-valve had been identified as the cause of several accidents.
In case of the 737 rudder problem the conception was also that all swans were white, until presence of a black swan (the PCU) was identified.
That would be the one where the retrofitted rudder controls (to fix the problem) included duff control rods that could also lead to uncommanded hardover ?
I think the investigation in that case included a lot of serious test rig kit with rudder assemblies in cold boxes etc. - for G-YMMM you might want most of a wing (+engine) in a cold box. Yikes.
Comet hulls in swimming pools also come to mind.
I wonder if there will be that level of resource put into this incident at this point - at some point, I guess, they decide not to spend any more on investigating what is clearly a very very rare event.
That B737 rudder issue, and the Comet, weren't investigated in the level of detail required until after multiple hull losses - I wonder if we'll ever get the answer on G-YMMM...
