Checklist for Long-Term Storage and Preservation of Aircraft

Whether due to seasonal downtime, deployment abroad, or scheduling constraints, there are many situations where aircraft need to be stored for extended periods. Long-term storage presents a unique set of risks—ranging from corrosion and component degradation to wildlife intrusion—that can compromise both airworthiness and insurance coverage.

Preserving your aircraft properly during periods of inactivity not only protects your investment but also demonstrates responsible ownership to insurers. A documented, checklist-driven approach to long-term storage helps mitigate preventable damage, ensures regulatory compliance, and supports future insurance claims or policy renewals.

Why Long-Term Storage Procedures Matter

When an aircraft remains stationary for weeks or months, moisture, pressure loss, fluid breakdown, and contamination can slowly take a toll on key systems. Without active flight operations to circulate fluids or activate components, systems like the fuel system, brakes, avionics, and hydraulics are more susceptible to failure upon reactivation.

Many insurers consider storage environment, preparation process, and duration when evaluating risk. If a claim arises due to damage during storage—especially corrosion, electrical shorts, or vermin damage—having proof that proper procedures were followed can significantly improve your position.

Long-Term Storage & Preservation Checklist

Use the checklist below to properly prepare your aircraft for safe, insurable long-term storage:

• Engine and Fuel System
  • Add fuel stabilizer to prevent degradation and varnish buildup
  • Top off fuel tanks to minimize internal condensation
  • Fog engine cylinders with preservation oil or desiccant plugs
  • Drain carburetor or fuel injection system if required by manufacturer
• Airframe and Exterior
  • Wash and wax airframe to protect paint from dust and UV damage
  • Install inlet, exhaust, and pitot/static covers
  • Cover aircraft with fitted weatherproof tarp if stored outside
  • Apply corrosion inhibitor to vulnerable surfaces (e.g., landing gear struts)
• Interior and Cabin
  • Remove food, beverages, and non-essential materials
  • Install moisture absorbers to prevent mold and mildew
  • Crack open cabin vents slightly (if safe) to allow air circulation
  • Disconnect and remove battery, or connect to maintenance charger
• Landing Gear and Tires
  • Inflate tires to maximum rated pressure
  • Jack aircraft or roll slightly every 30 days to prevent flat spots
  • Apply tire covers to protect from sunlight and UV damage
• Documentation and Logbooks
  • Record preservation actions in maintenance logs
  • Note date aircraft was last flown and expected return to service
  • Include any manufacturer-specific guidance followed

Insurance Considerations

Some insurance policies include provisions that are impacted by storage decisions—such as requiring hangar storage for hull coverage, or mandating periodic inspections. Always notify your insurer of long-term storage plans, and ask whether changes in location or usage status require endorsement updates. Keeping documentation of your storage preparation can help support any future claim resulting from weather, theft, or deterioration.

Common Preservation Mistakes

• Failing to treat the engine with fogging oil, resulting in cylinder corrosion
• Leaving avionics powered or connected to a failing battery
• Improper sealing, allowing animals or insects into the aircraft
• Storing outside without UV shielding or proper surface protection

Tools and Technology for Preservation

Several manufacturers offer preservation kits and specialty equipment designed for long-term aircraft storage. From desiccant plugs and battery maintainers to custom-fit canopy covers and automated logging apps, these tools streamline the process and offer additional layers of protection. Some maintenance software platforms even allow you to tag aircraft as “in preservation” and set reminders for renewal intervals.

Conclusion

Long-term aircraft storage, when done correctly, prevents costly degradation and upholds the standards insurers expect. By following a proven checklist, applying the right materials, and maintaining transparent records, you ensure your aircraft will be ready to return to the skies safely—and covered—when that time comes.

Whether you’re planning for seasonal downtime or an extended break in operations, this checklist empowers you to store with confidence, protect your investment, and maintain a solid insurance profile throughout the process.