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Exhaust Systems 101: Not So Silent Killers

Usually the only way to thoroughly inspect an exhaust system is to completely uncool the engine like we're doing on the Lycoming below.

Piston-powered airplanes aren’t exactly free of vibration and that beats the heck out of exhaust systems. That means that between-annual inspections are important, especially if you think the system was subjected to unusual punishment. Ever pull the mixture back for shutdown and the backfire sounded like a shotgun? That could have done some damage to the exhaust system’s welds and baffling, so you better get a look at both the carb and the pipes. Or the stubborn hot start that made a pretty good pop out the muffler when the engine finally lit. But there is regular exhaust system wear and tear that happens we’ll before TBO under even the most conscientious and normal engine operation—what could possibly go wrong?

THEY’LL LAST HOW LONG?

No nearly as long as you think. Pretty much forget most of what you know about automotive exhaust systems. Aircraft exhaust components live different lives. Just about every mechanic we talk with agrees that many aircraft exhaust systems won’t make it to the engine’s TBO. Fly a turbo? You’ll likely be replacing exhaust components more frequently, as the term “torching” is one you’ll hear frequently around shop floors.

Larry Anglisano

Editor in Chief Larry Anglisano has been a staple at Aviation Consumer since 1995. An active land, sea and glider pilot, Larry has over 30 years’ experience as an avionics repairman and flight test pilot. He’s the editorial director overseeing sister publications Aviation Safety magazine, IFR magazine and is a regular contributor to KITPLANES magazine with his Avionics Bootcamp column.