and yet again my question on Prune is how necessary and safe is this exactly?
I am probably not the right person to debate the necessities with, as I hate the thought of aircraft in museums. They were made to fly!!!!
As for safety, it can be done very safely and with minimal risk. Look no further than the RAF BBMF. Their record is as good as it is because they have a team of dedicated, highly trained and experienced engineers to give the airframes all of the TLC they will ever need from the moment they are shut down. Yes, it's expensive.... but so is anything else that's worth doing. If safety was a big issue then the Flight would be disbanded and millions would be saved.