How Faulty Aircraft Mufflers Can Pose a Serious Danger

Unlike vehicle aircraft mufflers that are mainly used to reduce the noise from a combustion engine, aircraft mufflers play a more crucial role: They don’t just reduce the noise but also keep the exhaust gases away from the engine and fuselage and supply cabin heat and carburetor. 

The aircraft muffler’s role is so significant that if they fail, it can lead to serious consequences that include carbon monoxide poisoning, serious injuries, fire, and total loss of the plane. 

Wear and tear in the metal and leaks in the muffler can also lead to partial or complete engine power loss. 

The Federal Aviation Administration has found an increasing number of engine failures in recent years caused by faulty exhaust mufflers. FAA engineers found that most cases involved wear and tear on the inside of the system that was not readily visible to both the pilot and mechanic. 

Between 2011 and 2019, FFA examined 23 accidents or incidents and found that muffler failures accounted for around 20% of the exhaust failures, while erosion and carbonizing were the most common causes. 


What Operators and Owners Can Do 

As an owner or operator, you should at least familiarize yourself with the parts and pieces that make up the aircraft exhaust system. Doing so will help you identify abnormal or defective areas or changes that were not there since the last inspection. 

Keep in mind that you are responsible for ensuring that any defects are immediately addressed after inspections. 

Another thing you can do is have your mechanic remove the heat shroud to inspect the ducting connection, heat exchanger, and other internal components. However, there is a less invasive way to improve visual evaluation, which is performed using a borescope inserted into one end of the removed muffler. 

 And should he detect problems in the mufflers, exhaust stacks, and tailpipes, the FAA engineers recommend complete replacement rather than repair, a process that is more complicated and time-consuming because it requires special tools and welding skills. 

Should you insist on repairs instead of replacement, authorities recommend that you only consult with an FAA-certified repair station. 


Telltale Signs of a Faulty Exhaust System 

Knisley Welding, one of the leading US manufacturers of aircraft exhaust components, has shared some tips on how to identify signs of a faulty exhaust system.

  1. Leakage. If you see black or gray powder near the exhaust system components like the external joints, flanges, or welds, it might be a sign of a leak. 
  2. Misaligned components. Missing, bent and loose parts are common signs of improper installation of the exhaust system components. 
  3. Structural deterioration. Dents, cracks, corrosion, discoloration, thinning, and weld separation are the most common telltale signs of this problem.