Exhaust Inspection – FAA AC91-59A
by FAA AFS-300
SUBJECT: Inspection and Care of General Aviation Aircraft Exhaust Systems
This advisory circular (AC) emphasizes the safety hazards of poorly maintained aircraft exhaust systems (reciprocating powerplants) and highlights points at which exhaust system failures occur. Further, it provides information on the kinds of problems to be expected and recommends pilots perform ongoing preventive maintenance and mechanics perform maintenance.
This AC provides an acceptable means of complying with the regulations; however, it is not the only means of compliance. This AC is not mandatory and does not constitute a regulation. When this AC uses mandatory language (e.g., "must" or "may not") it is paraphrasing a regulatory requirement or prohibition. When this AC uses permissive language (e.g., "should" or "may"), it describes an acceptable means, but not the only means, of complying with regulations. However, if you use the means described to comply with a regulatory requirement, you must follow it in all respects...
Click here to read the full FAA Advisory Circular, Inspection and Care of General Aviation Aircraft Exhaust Systems, 91-59A.