Exhausting

Editorial Staff

Monday, August 22, 2022 at 12:30 PM ET

Verified

** Guido Gehrmann** Courtesy of Flying Bulls

Key Takeaways:

Multiple aircraft reported failures in their exhaust systems, predominantly involving cracks, defective welds, or component disengagement.
Many of these issues occurred in turbocharged aircraft, where high heat and pressure environments contributed to blistering, pitting, and structural fatigue.
Consequences included exhaust leaks, loss of pressurization, and decreased manifold pressure, with some defects proving challenging to detect during routine inspections.

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Cessna T182T Turbo Skylane

Cracked And Leaking

During an annual inspection, the overboard exhaust pipe was discovered cracked and leaking at the wastegate attachment flange.

Part total time: Unknown

Cessna T206H Turbo Stationair

Defective Weld

Defective part is cracked at a weld and had to be replaced under warranty. The defective part came in a kit, part number 05J2883. The kit was installed to terminate AD 17-11-10.

Part total time: 60.0 hours

Cessna T206H Turbo Stationair

Disengaged Exhaust Elbow

Overboard exhaust elbow, between the wastegate and the tailpipe, disengaged from the wastegate flange, p/n 1250992-4, at the slip joint.

Part total time: 604.0 hours

Cessna T206H Turbo Stationair

Cracked Weld Assembly

While performing an oil change and AD 17-11-10, we discovered a crack in the weld assembly (p/n 12509927) found just after the wastegate. Installed new exhaust weld assembly gasket (p/n 24096-225N) and coupling (p/n S3262-6) IAW maintenance manual.

Part total time: 1452.0 hours

Piper PA-28-140 Cherokee 140

Cracked Collector Tubes

Exhaust collector tubes were cracked, detectable only after removal of exhaust and inspection with a bright light source. It appears the cracks went undetected through multiple previous inspections from a reputable shop. The exhaust is an aftermarket item.

Part total time: 2000.0 hours

Piper PA-46-310P Malibu

Loss Of Pressurization

Pilot experienced loss of pressurization and decreased manifold pressure. Examination revealed broken exhaust pipe (p/n 654321).

Part total time: Unknown

Piper PA-46-350P Malibu Mirage

Blistering, Pitting

During an annual inspection, the cylinder #6 exhaust transition pipe appeared to be starting to blister on the outside. The pipe was removed for interior inspection, which revealed deep cavities or pitting in the casing on the inside of the pipe. This pipe feeds one of the turbochargers, so it is extremely hot and under high pressure. The pipe was replaced.

Part total time: 230.0 hours

Piper PA-60-601P Pressurized Aerostar

Missing Balance Tube

Climbing through 13,000 feet, the pilot lost manifold pressure on the left engine, but later landed without incident. Inspection revealed heat and exhaust staining on the lower cowl. During additional examination, the technician found approximately four inches of the exhaust balance tube was missing. The missing pipe was not found in the cowling.

Part total Time: Unknown