How Do I Properly Maintain The Exhaust System Of My Light Aircraft?

For any aircraft, the proper maintenance of all its systems and components is vital for its proper operation, For this reason, routine checkups and regular inspections are scheduled to ensure a smooth, trouble-free operation.

An airplane mechanic working on an engine inside a hangar | From "How Do I Properly Maintain The Exhaust System Of My Light Aircraft", an article on

Specialized care for the aircraft not only helps in the prevention of further damage (which could otherwise cost a fortune to repair) but also to spot any other serious problems that may arise with regular use.

The plane’s exhaust system needs particular attention by attending mechanics. Meticulous examination and visual checks are required. When aircraft repair technicians go about inspecting the aircraft’s exhaust system for maintenance, they pay attention to the following:

Mufflers and heat deflectors

Signs of overheating and metal fatigue may be seen as belts or bumps on the muffler and heat baffles. With that in mind, these components must be removed for close examination during a leak inspection, using a bright light or a specialized inspection camera.

Deterioration generally results in the thinning of the muffler sidewalls. Therefore, to properly assess the integrity of the muffler, an awl would be used to inspect the walls for their thickness.

Any exhaust leaks

Leaks can be visually detected as grayish or sooty debris around the suspected area, or perhaps telltale yellow spots or streaks inside the exhaust system.

Sometimes, however, aircraft exhaust leaks leave no readily discernable clue about their presence; they’re just too difficult to plainly see. Leaks should be thoroughly investigated using the vacuum and soapy water method in this case.

In addition, to detect exhaust leaks around the joint area, an equally detailed evaluation is carried out using load gauges and pressure systems.

Exhaust cylinders and flanges

Corrosive exhaust gas leaking around the aluminum gasket dissipates through the cylinders and flanges. This can be observed visually and is a “must-have” when inspecting the exhaust system of an aircraft. Left unchecked, severe pitting can occur, requiring resurfacing.

The integrity of other connections

When inspecting the aircraft exhaust connections, technicians would usually test if the seals (clamps and gaskets) are loose or already slipping. If the seals are not properly secured, you can expect leaks that would lead to more serious exhaust system problems.

Manufacturers typically have instructions on how to maintain, repair, or replace these connections, and trained repair and maintenance technicians should know how to deal with these issues.

Other maintenance and inspection tips

An aircraft exhaust system is critical to the proper operation of the aircraft and must be inspected and maintained regularly to ensure a safe flight. The following are some of the maintenance tips for aircraft exhaust systems;

  • Break down all exhaust parts and components from the steel and the muffler.
  • Check each part for possible leaks or cracks.
  • If any part is damaged, be sure to replace it, as well as to replace any missing features such as bolts, nuts, or plugs
  • When inspecting the exhaust system, avoid using pencils as graphite weakens the metal when exposed to heat, making it vulnerable to cracks.
  • During a ‘magneto check’, if the ignition switch is accidentally closed, it is best to wait for the entire engine to shut down and restart.
  • A simple prerequisite is to keep the engine as cool as possible when exiting and as hot as possible so that the exhaust gases extend the life of the exhaust systems.

A Final Word About Maintaining The Exhaust System Of Your Light Aircraft

Regular care and routine maintenance of your plane’s exhaust system are necessary to ensure the smooth and continued operation of your aircraft. 

There are some maintenance action items that you can certainly do on your own. We, however, recommend that you also check in with your plane’s certified aircraft mechanic to thoroughly inspect your exhaust system, your engine, and other vital flight systems every few months or every year at the very least.

Knisley Welding Inc. has been a family-owned and operated business serving the aviation community since 1974. We provide Designated Manufacturing Inspection Representatives (DMIRs) on-site, as well as 8130’s upon request. 

For more information about our exhaust system maintenance program and inspection services, give our team a call at (800) 522-6990 today.