AD FAA-2007-28431

We are adopting a new airworthiness directive (AD) to supersede AD 76-23-03 R1, which applies to certain Alexandria Aircraft, LLC Models 17-30, 17-31, 17-30A, and 17-31A 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 AD reduces the exhaust system inspection interval; requires a more detailed inspection of the muffler; and requires replacement, reconditioning, or repair of the exhaust system if cracks or defects are found. This AD also requires P-lead rerouting. We are issuing 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.