Summary
We propose to supersede an existing airworthiness directive (AD) that applies to all Piper Aircraft, Inc. Models PA-31, PA-31-325, and PA-31-350 airplanes. The existing AD currently requires a detailed repetitive inspection of the exhaust system downstream of the turbochargers and repair or replacement of parts as necessary. Since we issued that AD, forced landings of aircraft have occurred due to exhaust system failures upstream of aircraft turbochargers and between recurring detailed inspections. This proposed AD would require both visual and detailed repetitive inspections, expanding the inspection scope to include the entirety of each airplane exhaust system. We are proposing this AD to prevent the possibility of an inflight powerplant fire due to an exhaust system failure.