Originally Posted by
roscoe1
Of course it goes without needing to say if the mfg says parts are to be pitched then out they go. In cases where that is not specified there will always be people who see no reason they shouldn't reintrroduce items that pass the prescribed inspection or overhaul back into service. You have no idea how far the gearbox fell, how it landed, if it was properly protected in a can or sitting on rubber tires. I think its fine if regulators were to ban reuse of accident parts or assemblies but they would never do that because there are too many parameters to define. Manufacturers would love it, operators would have some legitimate complaints. Turnng a t/r driveshaft into a twisted broken mess from a tail rotor strike might not be a reason to pitch a gas coupled compressor rotor or at least it's housing, for example. I am not saying it would be a good idea, just that it is more complicated in a world where people weigh money and convenience against what they think is being safe.
Yes, the number of parameters to define is what makes the potential recovery method in-adapted and there goes the risk. Especially, rotor strikes can take so many different dimensions. From the heli tipping over with engine off (yes it happened when a drunk driver drove into an EMS heli) all the way to a full-blown shakeout as the movie shown above.
Take the rotor mast for example, it is stainless steel, if it proves to be dimensionally perfect upon inspection with high grade equipement. what are we to think?
- a pure scientist would say: it proves the metal suffered no plastic deformations and thus as no memory of the event, it is then serviceable.
- a person with a stake in the safety of the aircraft would say: I don't know…., scrap it!
The aviation industry has been long educated to change parts just because we don’t know any better, but in a world that will become increasingly resource constrained it hold little merit.