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Older mufflers may be dangerous

It is just a suggestion from the FAA, not an order, but you probably ought to replace mufflers that have been in service for 1,000 hours or more. A university study shows older mufflers are involved in a high percentage of accidents related to carbon monoxide (CO) poisoning.

The FAA tasked Wichita State University to study the matter. The report shows that in carbon monoxide-related cases where the muffler was identified as the source of the CO leakage, 92 percent of the aircraft had a muffler with more than 1,000 hours of service.

The suggestion is contained in a May 7 special airworthiness information bulletin (SAIB). When developing the SAIB, the FAA considered the NTSB investigation of an accident on Dec. 17, 2000, in which a Beech Model BE-23 aircraft crashed, killing the commercial-rated pilot, the sole occupant of the airplane. The NTSB determined the probable cause of the accident was in part “the pilot’s incapacitation due to carbon monoxide (CO) and a fractured muffler.”

You can find all SAIBs online, and you can subscribe to future SAIBs. Click on “Subscribe,” identified by the green checkmark.

Alton Marsh

Alton K. Marsh

Freelance journalist
Alton K. Marsh is a former senior editor of AOPA Pilot and is now a freelance journalist specializing in aviation topics.

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