Masthead.

Putting Your Aircraft to Bed

The Before and After of Aircraft Winter Storage

FAA Safety Briefing
7 min readOct 27, 2023

--

By Rebekah Waters, FAA Safety Briefing Magazine

Airplane with covers on it.

Winter weather can take its toll on many things: roads, trees, cars, and of course aircraft. Some aircraft continue flying year-round, but some settle down for a long winter’s nap. Any aircraft that spends the winter months in hibernation should be properly prepped and protected.

Proper winter storage has two main parts. There are things you can do now to limit the corrosion or damage Old Man Winter might throw your way. There are also things you will need to do later — when your aircraft comes out of storage — to make sure it is safe and ready for its first spring flight. Let’s take a look at the “before” and “after” of aircraft winter storage.

Magazine cover.

Preparing for Winter Storage

Knowing that aircraft can deteriorate quickly when they sit around not being used, you’ll want to have a plan in place if you decide to store it through the winter months. Giving your aircraft a washdown and clean out is a good start, but if you plan on storing your aircraft for a significant amount of time this winter, you may need to do more. Most manufacturers recommend taking some special steps if an aircraft will be inoperative for more than 30 days.

A good first step is to familiarize yourself with the pilot’s operating handbook (POH) or aircraft flight manual (AFM). Reread the sections on winterizations — even if you read them last year. This will tell you if you need to take action to protect internal parts like using fogging oil to prevent corrosion or a fuel additive to protect the fuel. Remember moisture is your enemy. Most of the manufacturer’s recommendations will be aimed at keeping your engine dry and free of corrosion. Your mechanic can also be a good resource to make sure you haven’t forgotten any of the recommended crucial steps.

To find out what else goes into successful aircraft winter storage, I talked to Gary Suozzi, aviation safety inspector with the FAA’s Aircraft Maintenance Division. Suozzi outlined some basic steps to remember like chocking the wheels (front and back) and making sure to release the parking brake.

“If the parking brakes are applied over a period of time, it could cause a flat spot on the rotor disk or brake pads,” Suozzi says.

He also recommends making sure that the fuel cocks are closed and the master switches are off. This will prevent any condensation or moisture from collecting during storage. Some other items to consider before storing your aircraft include changing the oil and filling the fuel tanks. New oil provides greater protection to the engine’s internal components and filling the fuel tanks will help prevent condensation from forming and/or freezing, which can cause damage to the fuel cell or airframe.

Extreme or extended cold can create fuel leaks as metal connections contract allowing rubber fittings to become loose. When stored outside, check your aircraft during periods of extreme or extended cold. Checking for leaks can save money and the amount of cleanup time needed for the lost fuel. In most cases, simply tightening the fuel line clamps will stop the leaking.

Airplanes in front of hangars.

Where you store your plane will have a big impact on how your plane weathers the winter months.

“It is best to keep the aircraft in an enclosed environment whenever possible — especially in areas with salty air,” says Suozzi. This could be a tent or a hangar. “What is important,” he continues, “is to keep it away from any wind-driven events, if possible, especially the night before flight.” If this isn’t possible, Suozzi recommends applying a canopy cover or tying a dust sheet over the cockpit area to protect the aircraft from above. “But do not place a cover directly on the windshield,” he warns. “Water that leaks through the cover could lead to crazing. Also cracks could occur if large amounts of water collect under the cover, and temperatures fall below freezing,” adds Suozzi. Another thing to remember when outside storage is unavoidable is to store the propeller in the vertical position. “This will avoid an accumulation of water on the spinner which would cause an imbalance,” says Suozzi.

Storing your aircraft inside a warm cozy hangar may sound ideal. In fact, it’s so ideal that animals might seek accommodation in your sheltered aircraft. To keep critters at bay, make sure you plug and cover any spots where they might gain entry including the pitot tube, access ports, and engine cowlings. When blocking the inlets, exhaust, and vents, use paper tape or another type of barrier. This should help prevent animals from making your aircraft their own winter storage spot.

While not everyone can keep their aircraft in a heated hangar over the long winter months, there are other ways to keep your aircraft protected. If you are using tie-downs, think about what surface your plane will be parked on. Is it paved or unpaved? When considering what type of anchor you will need, factor in the weight of the aircraft. Make sure to select an anchor with appropriate holding power.

Use the manufacturer’s recommended baffling and covers. It is also important to adjust control cables to compensate for cold contraction. Removing wheel covers can reduce the chance of frozen slush locking the wheels and brakes. If you can’t cover your entire aircraft, it is recommended to at least cover the cockpit, engine, and wings. Covering is the ultimate protection. When this isn’t an option, inside covers are the next best option.

Finally, don’t forget about the battery. Keep it charged or remove it if your aircraft is parked outside. Suozzi recommends purchasing a “battery tender” (a device that charges and maintains a battery) if electrical or solar power is available. “It will save you the cost of a new battery plus the labor,” says Suozzi. You’ll want to take the same care of the battery in your emergency locator transmitter (ELT). It is important that this battery is charged and ready to perform properly if you need it to.

Be sure to take care of your emergency locator transmitter (ELT) battery. It is important that this battery is charged and ready to perform properly if you need it to!

De-winterizing Your Aircraft

It may seem a long way off, but before you know it, Punxsutawney Phil and his elusive shadow will be hogging the spotlight. Shortly after that, when the weather starts to warm, it will be time to bring your aircraft out of storage. Let’s look at the steps you can take to bring your aircraft safely out of hibernation.

Start with a thorough inspection. Check all hoses, flexible tubing, and seals for signs of deterioration like cracks, hardening, and lumps. Tighten loose clamps and fittings. Make sure to inspect the heater system for leaks that could lead to carbon monoxide problems. Look for guide wires that are unraveled or corroded. You should carefully double-check any areas where damage could result in a catastrophic condition.

“Mother Nature is not your friend,” says Suozzi. “That is why I recommend using a hangar whenever possible.” But even if your aircraft was stored in a hangar over the winter, a good preflight is essential to a safe operation. Look at the aircraft from the standpoint of a mechanic. “Metal contracts and expands with changing temperatures so make sure to look for distortions,” adds Suozzi. If you note any distortions, get a mechanic to inspect them. Finally, Suozzi reminds us that even though you did your best to keep them out, don’t forget to check for small animals and nests in the fuselage. Besides the surprise factor of finding one, these critters could create a fire hazard.

Keeping tie-downs secure and removing snow and ice loads from the aircraft both go a long way to protecting your investment.

Suozzi also points out that winter storage can impact your annual inspection. Annual inspections, as the name suggest, are good for twelve months. The months your plane is in storage count towards those 12 months, so keep an eye on when the next inspection is due.

Storing your aircraft for the winter is no small feat. It is far from just parking your plane for a few months until you are ready to fly again. But, if you are thoughtful and careful about the “before” and “after” of winter storage, you’ll be ready for another year of flying safely.

Broken propeller.
To avoid damage like this Cessna 172 prop, always check carefully for cracks.

Do you have any helpful winter storage tips you’d like to share with our readers? Send them to SafetyBriefing@faa.gov.

Learn More

Rebekah Waters is an FAA Safety Briefing associate editor. She is a technical writer-editor in the FAA’s Flight Standards Service.

Magazine.
This article was originally published in the November/December 2023 issue of FAA Safety Briefing magazine. https://www.faa.gov/safety_briefing

--

--

FAA Safety Briefing

Official FAA safety policy voice for general aviation. The magazine is part of the national FAA Safety Team (FAASTeam).