On occasion an aircraft may end up sitting for a longer period than normal. When this occurs. It is important to take the necessary action to preserve the aircraft. With fixed wing aircraft you are going to be most concerned with the engines as they are the costliest when it comes to maintaining the aircraft. With rotorcraft you will need to preserve the main rotor transmission and the tail rotor gearbox in addition to the engines.
Different manufactures have different criteria for preservation, so it is important to refer to your specific aircraft’s maintenance manual. Failure to preserve your engines and other required components can result in rust and deterioration which in turn will end up costing the operator a substantial amount of money. Also, bearings within the engine do not do well stationary. The engine needs to be turning to provide continuous lubrication and if it is stored for an extended period and not properly preserved it has the potential to develop a catastrophic failure when put back in service.
Quite often aircraft go unpreserved, and it is not noticed. If it does go unnoticed it’s not always going to be worst case scenario. Worst case being catastrophic failure of a bearing within your engine and if you are unaware of the fact that the aircraft sat unpreserved for a year you just unknowingly incurred an unnecessary expense. It is important to ensure that you have the right professional representing you when buying an aircraft. If it is caught during an appraisal or a prebuy inspection it is much easier to deal with.
