Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-10-33 R1
August 16, 2010
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) communicates an
airworthiness concern to all owners and operators of reciprocating
engine-powered airplanes that use an exhaust system heat exchanger for
cabin heat. This revision clarifies the airworthiness concern is for
aircraft that use an exhaust system heat exchanger for cabin heat.
At this time, this airworthiness concern is not considered an unsafe
condition that would warrant an airworthiness directive action under
Title 14 of the Code of Federal Regulations (14 CFR), part 39.
Background
The Federal Aviation Administration tasked Wichita State University to
conduct research that focuses on carbon monoxide safety issues as they
apply to general aviation products. A technical report titled
“Detection and prevention of carbon monoxide exposure in General
Aviation Aircraft, Document No. DOT/FAA/AR-09/49, dated October 2009”
is available from the National Technical Information Services using the
contact information noted below and is also available electronically at
http://www.tc.faa.gov/its/worldpac/techrpt/ar0949.pdf.
The report 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 percent
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 December 17, 2000, where a Beech Model BE-23 aircraft
impacted terrain 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.”
Recommendation
The FAA recommends that you do the following:
Replace the mufflers on
reciprocating engine-powered airplanes that use an exhaust system heat
exchanger for cabin heat 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 December 17, 2003, and Advisory Circular 43-16A,
Aviation Maintenance Alert (AMA), issued October 2006, All Powered
Models, Carbon Monoxide Poisoning Potential.
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 following their applicable maintenance manual
instructions.