Summary
We propose to supersede Airworthiness Directive (AD) 76-23-03- R1, which applies to certain Alexandria Aircraft, LLC (Bellanca) Models 17-30, 17-31, 17-30A, 17-31A, and 17-31ATC airplanes. AD 76-23-03-R1 currently requires you to inspect the muffler and tailpipe assemblies for cracks and inspect the exhaust assembly for freedom of movement at the ball joints. Since we issued AD 76-23-03-R1, we have received additional reports of in-flight exhaust system failures. Consequently, this proposed AD would reduce the exhaust system inspection interval; require a more detailed inspection of the muffler; and require replacement, reconditioning, or repair of the exhaust system if cracks or defects are found. This proposed AD would also require rerouting of the magneto "P" leads. We are proposing this AD to detect and correct cracks in the exhaust system, which could result in heat damage to magneto electrical wiring and smoke in the cockpit. This failure could lead to loss of engine power and/or a fire in the engine compartment.