I spent quite a few years in the aircraft business. Our company kept a fleet going that were commissioned in the fifties. We had to sometimes go to the boneyard for parts. Also we worked on one aircraft even on overtime to finish. Flew one time and then to the boneyard. Also need to add there is a place in the Mojave desert in California where there was a number of commercial aircraft parked. Some were new and some used. Some from bankrupted airlines. I was amazed at one facility where I worked there were two 747 parked with two engines missing. I being nosy asked what the aircraft were there for same answer bankruptcy. The engines were removed by the company that had leased them to the airline.