The FAA has issued a Special Airworthiness Information Bulletin advising all owners and operators of reciprocating engine-powered airplanes of an airworthiness concern about carbon monoxide.
The FAA tasked Wichita State University to conduct research that focuses on carbon monoxide safety issues as they apply to general aviation. A technical report, “Detection and prevention of carbon monoxide exposure in General Aviation Aircraft, Document No. DOT/FAA/AR-09/49, dated October 2009,” shows that after researching National Transportation Safety Board (NTSB) accidents related to carbon monoxide (CO) poisoning, the muffler system was the top source of CO. For the CO-related cases where the muffler was identified as the source of the CO leakage, 92% had a muffler with more than 1,000 hours of service.
When developing this SAIB the FAA considered the NTSB investigation of an accident on Dec. 17, 2000, where 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.”
While the airworthiness concern is not considered an unsafe condition that would warrant an airworthiness directive, the FAA has issued some recommendations:
- Replace mufflers on reciprocating engine-powered airplanes with more than 1,000 hours on the muffler and at each 1,000-hour interval, unless the manufacturer recommends or FAA regulations require a more frequent replacement.
- Review and continue to follow the guidance for exhaust system inspections and maintenance in SAIB CE-04-22, dated Dec. 17, 2003, and Aviation Maintenance Alert (AMA), All Powered Models, Carbon Monoxide Poisoning Potential, October 2006 issue of Advisory Circular 43-16A.
- Use CO detectors while operating your aircraft as recommended by SAIB CE-10-19R1, dated March 17, 2010.
- Continue to inspect the complete engine exhaust system during 100-hour/annual inspections and at inspection intervals recommended by the aircraft and engine manufacturers in accordance with their applicable maintenance manual instructions.
For more information: 816-329-4145 or FAA.gov.