Call Us Today:  952-698-3000

Keeping Your Piston Engine in Prime Condition

For those pilots flying piston-powered airplanes, here are some tips for keeping your engine in prime condition – let’s get started!


Piston-powered engines operate much like a car engine, with pistons going up and down, generating enough power to turn a propeller. This type of engine is a descendant of traditional steam engines originally invented more than four centuries ago.

The other popular type of engine for smaller planes is known as a turboprop-powered aircraft. Turboprop engines use something similar to a turbine to derive energy through wind flow. A turbine is a rotating fan that uses air or fluid to create motion. Simplified versions of this type of engine are windmills and watermills, each creating rotational energy through wind and water flow, and lent inspiration to today’s turbine engines. Turboprop-powered planes may or may not have a propeller.

When it comes to maintenance, piston-powered engines are generally lightly regulated in comparison to turboprop engines. The Federal Aviation Administration (FAA) leaves many of the maintenance duties of a piston engine in the hands of the pilots and certified mechanics. Turboprop engines, on the other hand, require an extremely detailed operation, maintenance and overhaul by a professional to be certified for flight.

Since the main responsibilities involved in maintaining your piston-powered aircraft fall on your shoulders, you should be prepared to know when something is in need of inspection, servicing or replacement. With a few easy-to-remember tips, you can keep your engine in prime condition, so you’re always ready for take-off.


Understand the TBO of Your Engine

The total time between overhaul (TBO) is a measure of the number of hours the engine manufacturer recommends to operate the aircraft before the engine needs to be taken apart and repaired or overhauled. The TBO for a piston aircraft is generally 2,000 hours, although that number differs from engine to engine.

Some pilots decide to push their engines past TBO with no negative effects, while some will need to make major service repairs before they reach the maximum TBO. Regardless, with proper and regular maintenance, you can reduce repair costs and extend the overall life of your airplane.

In general, it’s pretty expensive to conduct a complete engine overhaul, with prices ranging from about $15,000 for a simple four-cylinder engine to approximately $50,000 for a six-cylinder turbocharged engine. Even just replacing the cylinders without a complete engine overhaul can be expensive.

That’s why it’s so important to keep your piston engine in tip-top shape.

Don’t Start Your Piston Engine in Cold Weather

Don’t attempt to start your piston-powered aircraft when the weather is below freezing. This can cause serious damage to the engine and mean big repair bills for yourself. For example, aluminum pistons heat and expand almost twice as quickly as the steel cylinders which contain them, causing serious issues. The cost to replace just one cylinder can be upwards of $2,000, parts and labor, so it’s best to avoid cold starts.

Starting a cold engine can cause 500 hours worth of cruise wear and tear – a pretty big number to those who want to keep their piston aircrafts healthy for the foreseeable future. In order to prevent damage caused by cold starts, there are three main pre-heating options you can choose from:

  1. Pay for forced-air cart services – most fixed-base operators (FBOs) will have this service available. It simply involves hooking a forced-air cart up to the heating tube on your plane to warm engine components. Normally, this service costs anywhere from $15-$30.
  2. Install an electric heating system – this system allows the plane engine to warm up by attaching electrical heating elements to the cylinders, oil pan and crank case of your engine. All you have to do is plug the system into an outlet and your engine will warm up.
  3. Rent a storage spot in a heated hangar – the biggest advantage to renting heated hangar space is that it keeps all of your engine components equally warm, whereas the other two methods heat engine components unequally, causing different contraction and expansion rates.

Check and Replace Air Filters

You should always check and replace air filters when necessary. It’s inevitable that dirt or dust will make its way into your engine – and the air filter is the first defense and stopping large chunks from damaging engine components. If your plane’s air filter is dirty, poorly fitted or worn out, it can cause things such as the piston ring, ring groove and cylinders to deteriorate.

In order to ensure your air filters are up to flying standards, we recommend cleaning the air filter daily, especially when operating in particularly dusty conditions. If you notice any rips, holes or deterioration in the filter you should replace it as soon as possible.

Check the Air Induction System

Before taking flight, inspect the whole air induction system to remove unfiltered air in the filter, fuel injector and carburetor. Additionally, if your aircraft has been stored for a lengthy period of time or is parked in a dusty area, inspect and clean the unfiltered portion of your plane’s induction system to ensure everything is operable.

If you notice dust, dirt or another residue in the induction system beyond the air filter, it’s safe to bet that you have a bad air filter.

Avoid Long Periods of Idle Engine Time

When you let your aircraft sit for a long time without use, it’s at risk of developing devastating corrosion and rust. Engines that are operated frequently are much more likely to meet the expected TBO. For example, flight school engines receive abuse all day long and almost always hit or exceed TBO.

Piston engines that sit for lengthy periods of time break down much quicker than those that fly consistently. And it’s not enough to simply turn on the plane and let it run, like you would when warming up a car. The best way to ensure your engine stays in prime condition is to take flight regularly. If the engine is merely ground run, water accumulates in the oil and eventually turns into acid, a main cause of rust. Plus, you can bake or rupture delicate engine components like seals and gaskets. Piston-powered airplanes are built to fly — so don’t neglect your air time!

Know What to do in the Event of a Propeller Strike

As one of the more common problems faced by pilots flying piston-powered airplanes a propeller strike can cause stalling, gear failure and other malfunctions. Flocks of birds, powerlines, runway debris or hitting the ground upon landing can be a major concern for propeller-powered aircraft.

To help safeguard pilots against propeller strikes, the FAA has implemented a  foreign object debris (FOD) management program  to educate pilots about these risks. This program helps pilots understand how to identify, avoid and recover from potential propeller strike hazards.

Watch Out for Sticking Valves

When you have a sticking valve, you should notice it almost immediately when you fire up your plane’s engine. When a valve sticks, it causes the plane to run roughly at startup. Once the engine warms up, it may go away. However, if you notice an initial roughness, you should take your plane to a mechanic to get it checked out.

Although there’s an occasional exception, the exhaust valve is generally the main valve that tends to stick. To prevent the valve from sticking in the future, clean it of any contaminating materials, such as carbon.

Do you need help with piston aircraft engine maintenance?

Contact Citadel Aircraft Maintenance Today! Our team includes the best private aircraft mechanics in the greater Minneapolis-St. Paul area – we’re ready to service your plane so you never have to miss a day soaring through the sky in your piston-powered plane. From annual inspections to troubleshooting, repairs and more, we have the capacity to meet your unique aircraft maintenance needs.

The experience we offer gives pilots confidence in their aircraft and sets future expectations for a higher level of service. At Citadel Aircraft Maintenance, we will always treat our clients’ planes like our own.

Get in touch with our team for a free quote on your aircraft’s maintenance needs.

Contact us!