Protecting Your Aircraft's Value When Not Flying
Operators should know that each manufacturer has specific requirements for each model of aircraft. These guidelines are provided within their airframe, engine, and APU Maintenance Manual based off of duration and location of the aircraft being parked or stored.
However, here are some general things to keep in mind:
- First step is identifying if the aircraft will be parked or stored?
- Short-term or temporary parking of an aircraft is keeping it mission-ready, which may require routine exercising of the aircraft systems. Normal operation of aircraft engines, controls and systems helps to exercise and lubricate them preventing the accumulation of moisture in the oil and fuel systems.
- Long-term parking or storage of an aircraft requires specific preservation actions to be performed on the aircraft and engines. It is important for operators to understand the proper aircraft and engine preservation requirements for their aircraft. The level of preservation is dependent on the anticipated length of storage as outlined by the Engine and Airframe OEMs.
- Parking Aircraft- Standard maintenance practices:
- Recommend that the aircraft is parked inside a hangar
- If a hangar cannot be secured, it is advisable to park the aircraft into the prevailing winds and moor the aircraft if severe weather is predicted.
- Ensure the aircraft is on a level surface.
- Chock the main landing gear wheels.
- Install all aircraft safety equipment such as landing gear lock pins
- Ensure all access doors/panels are closed
- Set all master switches and controls in the Flight Compartment to Off or to a neutral position.
- Attach aircraft grounding cable.
- Center control surfaces and engage gust locks if equipped.
- Install all protective covers such as engine inlet and exhaust covers, pitot probes and static covers etc. Pay attention to all openings for potential of birds nesting, excessive rain ingress and the accumulation of debris.
- Periodically check tire inflation and rotate them to prevent flat spots from occurring.
- Check shock absorbers for proper inflation and wipe down struts with the appropriate fluid
- Periodically clean the aircraft to avoid corrosion.
- Recommend disconnecting the aircraft’s batteries when not in use.
- Storage of Aircraft- Standard maintenance practices (In addition to the standard maintenance practices listed above):
- We encourage aircraft owners and operators to thoroughly review ATA Area Chapters 10 & 71 in the Airframe Maintenance Manual and the Engine Maintenance Manual and the APU Maintenance Manual or if applicable Ground Handling and Service Manual for guidance on proper preservation procedures.
- With an aircraft in storage, fuel bio-contamination becomes a concern. It is necessary to routinely drain water from the fuel tanks and if possible perform a fuel contamination detection test.
- Some engines require the use of desiccant to be placed on a rack in the inlet and the exhaust of the engine. The inlets and exhaust are then masked off with plastic and humidity indicator cards are utilized to ensure that excessive moisture is not accumulating.
- Remember to stay on top of applicable calendar month inspections while the aircraft is in storage. This is VERY important!
- Returning Aircraft to Service from parking or storage:
- When returning the aircraft to service, be sure to return the aircraft back to its original configuration, remove all protective coverings and materials and perform a preflight inspection.