Airplanes that sit for extended periods tend to develop problems over time that may go undetected until you really need the airplane for your next flight. It is common to think that less flight time on an airplane leads to less maintenance problems, but that is only partially true. Low overall time is good, but extremely low or intermittent usage can be detrimental to your airplane and engine.
Ground Run-Up vs. Actual Flying
Some pilots believe that they can take their airplane out once a month and do a ground run-up on the engine to make up for lack of use. This approach; however, does not get the airplane up to full operating temperatures and power settings. Airplane engines actually benefit the most from going through a full flight cycle, including takeoff at max power, flying in cruise and normal power settings, and getting the oil warm enough to boil out any water or condensation that may have formed.
In addition to the engine, the airframe and other parts benefit from the regular use and flight of the airplane. Oleo struts get exercised; the batteries get charged; avionics are warmed up; wheels get turned; flaps get tested; gear gets exercised; and cables, pulleys, springs, and other flight control components are exercised.
The magic formula: 1 hour flight every 7 days
Ideally, I would recommend flying at least one hour per week on average. This is sufficient to keep the airplane in good shape for flying, and gives you a good reason to take a friend out for a $100 hamburger.
Continental’s IO-550 Installation and Operation Manual states the following: “Environmental conditions (humidity), seasonal changes, and engine usage influence susceptibility to corrosion. Engines that are flown occasionally (less than one time per week) are more vulnerable to corrosion under these conditions. The best method of reducing the risk of corrosion is to fly the aircraft weekly for at least one hour. The owner/ operator is ultimately responsible for recognizing corrosion and taking appropriate corrective action.”
Storage More than 30 Days – “Flyable Storage”
If you need to store the airplane for an extended period without use, this can be done if proper guidance is followed. Most manufacturers offer recommendations in the AFM for “flyable storage” procedures. This may include replacing the oil with special preservative oil, and other additional procedures as specified by the manufacturer. The guidance can typically be found in the “Airplane Handling, Service and Maintenance” section of your Airplane Flight Manual, with references to your engine and airframe maintenance manuals for additional maintenance-specific procedures.
Some climates may require additional preservation considerations:
- Close to oceans, lakes, or rivers
- Humid regions
Top Off the Tanks
It is also recommended to keep the fuel tanks topped off when storing the airplane for any length of time. This helps minimize the chance of condensation forming in the tanks.
Benefits of Frequent Flights:
- Engine warm-up
- Oil heated sufficiently to boil out the water/condensation in the oil (typically around 170-200˚F)
- Less susceptibility to corrosion
- Batteries recharged
- Avionics and electrical system actively in use and warmed up
- Oleo struts, seals, hydraulics, and other moving parts get exercised or checked
- Prop and prop governor exercised and oil cycled through system
- Landing gear gets exercised (if retractable)
- Flaps exercised
- Pilot proficiency, of course!
- Fuel and oil get used. When additional oil is added, it helps dilute the used oil making the oil incrementally cleaner between oil changes.
- Helps control the bug population!
- Flight control cables, pulleys, springs, etc exercised
Remember, 1 week = 1 hr flying
Ideas to Keep Your Airplane Flying
Not everyone has time or reason to fly one hour every week. If not, you should consider some alternative ideas for keeping your airplane flying or some other good ways to put the time to use.
Keep the airplane flying when you’re too busy:
- Hire a pilot to fly the airplane for one hour and evaluate the systems of the airplane
- Let a qualified pilot friend use the airplane
- Offer your flight instructor free time in the plane in exchange for keeping it flying regularly
- Find someone to manage the airplane and track the flight time and give them guidelines for how often you want the plane flown if you aren’t using it.
If you want to do the flying yourself, but want to make the most of the time, consider these ideas:
- Training – Probably the number one best use of the flight time if you have no other reason for the flight
- Practice – Fly practice approaches and maneuvers on your own, but have a plan
- $100 hamburger – Take a friend out for lunch at an airport restaurant
- Volunteer – These turn your flights into tax-deductible and rewarding experiences. Angel flights and PilotsNPaws are some examples. More ideas here: https://www.flyhpa.com/2015/06/volunteer-opportunities-for-aircraft-owners/
- Give someone their first airplane ride and help inspire future pilots
Remember, your airplane wants to fly!
How it Started
One of my best friends in high school, (Doug Gray) was a private pilot. He offered to take me up for a flight in a 1967 Cessna 150, N6228S. We took off from Calhoun, Georgia, and he took me on a scenic tour of the area, I was hooked. I later found out that my English teacher, (Jan Haluska) was also a flight instructor and the school was offering a ground school course the next year, which he taught, along with flight training with the goal of becoming a private pilot. I managed to talk my dad into funding the training, at the time the total cost was right around $500. Cessna 150 rental rates where $12 an hour, and the 172 we used for cross country was $15 an hour including fuel.
It started August of 1977. The fall semester rolls around, and I am enrolled in ground school, and if memory serves me, we met twice a week. First came the paperwork for my student pilot certificate, which at the time was included with the 3rd class medical. I loved ground school, especially learning navigation, plotting courses on the sectional, again this was before iPads and GPS, so we did a lot of dead reckoning and VOR navigation for cross countries. At the end of the course, I made an 83% on the Private Pilot written exam, remember this was before we had the question-and-answer books that on future test I would consume before taking a written.
The fun really began on August 22, 1977, it was my first flight. To my surprise we used the same Cessna 150, N6228S that my friend Doug Gray had taken me for a ride in. The Cessna 150 had a standard VFR instrument panel, with one NAV/COM, and one VOR CDI. No intercom, so no headset, at the time I didn’t know what I was missing. I didn’t get my first headset until I started my instrument training in 2003. I was a big guy, I was 6’ 4” and weighed 245 lbs. but I do not remember being uncomfortable in the 150 even with the instructor in the right seat.
First flight lasted .8 hours, and we accomplished orentation, shallow turns, stability, and effects of flight controls. Over the next few months we added steep 720’s, slow flight, stalls, turns around a point, S-turns, emergencies, landings, (short field, soft field and normal).
At this point I want to talk about a training experience that still stands out. We were close to solo and were practicing takeoffs and landings. Turning base to final Jan got very upset at the way I was cross controlling the aircraft. Cross control is when you are in, say a left turn, and use opposite rudder to line the nose up with the runway. So, he had me depart the pattern and head east to the practice area, and climbing up to 5500 feet MSL, he had me slow down to just above stalling speed, start a left shallow turn and add right rudder. As the airplane stalled I had the strangest sensation, no roller coaster has ever come close, instead of blue sky in the windscreen I was looking at brown ground, and as far as I could tell we were upside down, through the terror of the moment Jan talked me out of the spin, controls neutral, oposite rudder, pull slowly out of the dive. As we leveled off he asked me what altitude we were at, as I remember it was around 2,800 feet MSL. Then he asked me what would happen if I experenced this on base to final in the traffic pattern. The answer was obvious, I would be a pile of wreckage off the end of the runway with a very short-lived aviation career. Needless to say this cured my cross-control tendencies.
Another training event the sticks out in my mind was the first time we did takeoffs and landings at the High School runway. The runway was 1,500 feet long, not sure of the width, but it seems like we had about 5 feet on each side of the wheels when on the center line of the runway. Landing from the south you also had to go between a cutout in the trees to be able to stop in time on the runway. After getting confortable landing here every runway since seemed huge. I remember landing at Chattanooga (KCHA) on a night cross country and commenting to Jan, that I felt like I could of landed sideways on the runway, it felt that large.
Very soon after this I started wearing old shirts to all my flight lessons, the reason for this occurred on February 8, 1978. The lesson that day was stalls, takeoffs and Landing. As we were taxing back in Jan told me it was time for my first solo. I was very excited, and after some last minute advice from Jan, including watch for floating on landing the plane will be light with him not in the right seat, complete 3 takeoffs and landings to a full stop. It was a blast, and at the end of my shirt was shorter in the back because Jan cut the tail out of it signed and dated my solo [an aviation tradition]. Total flight time accumulated on the day of my solo was 18.1 hours. I was now officially a pilot with solo priveleges.
In my next article I start cross country training, when Jan decided that it would be best accomplished this in the 172. Checking out in N5970R was like moving into a 747, this started a love affair with one of my faviriote planes to date. Since this time I have flown over 900 hours in many different models of the 172 and feel like I am stepping into an old friend every time.
More about Randy here: https://www.flyhpa.com/team/randy-delong/
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