Airports Ed As I picked up the Lanc at LAP/LHR/Heathrow and was a hangar Brat I can't comment on the spares situation we seemed to manage . but prior to the Lanc I worked the Halton/Haslifax both in the hangar and workshop at Bovingdon and a lot of Spares were obtained from brand new Halifaxes which were being scrapped, Retested and recertified by certified inspectors and fitted to the aircraft when needed , if that was carried out on the Lancs I Don't know he only thing which wasn't tested were the Time Delay fuses for the Engine fire system, when you pressed the fire extinguisher button it fired the 1st of 3 bottles into the carburettor also set a BURNING fuse which 5 seconds later blew bottles 2 and3 which Hopefully extinguished any flame around the engine.Don't think they would allowthat these days.