Tips For Inspecting Aircraft Exhaust Systems

Knisley Welding would like to share some tips on how to inspect your aircraft exhaust systems to ensure that they are running at their optimal performance.

Related: Inspection of Aircraft Exhaust Systems – ederal Aviation Administration (FAA) has released Advisory Circular (AC) No. 91-59A

Knisley Welding understands how significant inspection is in keeping your aircraft exhaust at peak condition. Maintenance would do no good if the inspection conducted before it would not be able to provide an intensive appraisal of the aircraft exhaust system. With proper inspection, you will have a complete picture of how your aircraft exhaust system is doing, where the problem exists, and what to repair or replace. Without proper inspection, you are putting yourself at risk. A small issue, if not resolved, would lead to bigger problems such as poisoning, power loss, and even fire – very dangerous situations that could have been prevented if only there was proper inspection and that the right resolution was done.

By following below tips from Knisley Welding, you would be able to perform a more comprehensive inspection of your aircraft exhaust systems:

Inspection Tip Number 1: Read through Manufacturer Service Bulletins and Airworthiness Directives (or AD Notes).

These would tell you of criteria on how to determine whether an aircraft is still airworthy and how to resolve possible issues that cause failure to be airworthy. Ideally, AD notes would also contain manufacturer advice on when to pull out aircraft exhaust systems.

Inspection Tip Number 2: Check for leaks, corrosion, pitting, and metal fatigue.

These are issues that must be resolved as soon as you see them prevent further damage.

You can tell that there are leaks if you can see stains on the exhaust parts and that there would be signs showing where that stain came from.  Leak stains can be black, white, red or yellow.

Pinholes and thinning of parts can be caused by pitting and corrosion, Corrosion is often seen on parts located in lower areas where a collection of moisture is more possible.

Metal fatigue can be seen as a blister or a bulge on any metal part of your aircraft exhaust systems caused by heat. Parts with evident metal fatigue should be replaced as soon as identified.

NOTE: In marking exhaust parts, avoid using lead pencils as they give rise to cracks that grow to bigger problems!

Inspection Tip Number 3: Check for connections.

In inspecting connections, check whether seals (clamps and gaskets) do seal and slip joints do slip.  If they don’t you can expect leaks that could grow to more serious problems. As said on tip number 1, manufacturers should have instructions on how to maintain, repair, or replace these connections, so it is important that you read them.

For mufflers that have baffles, make sure that they are intact and are not distorted. This is to ensure that they would not end up obstructing the tailpipe. But first, ensure that your mufflers do have baffles in the first place.



Regular personal inspection is important. But seeking for professional inspection every now and then will ensure that your aircraft exhaust system is at its peak condition. When it comes to aircraft exhaust systems, Knisley Welding is the right place to avail of inspection services. After which, you can also get the best service to rectify issues that we can identify.

Always remember, for all your aircraft exhaust system-related needs, just call Knisley Welding and we will gladly help you out!