Inconel exhaust components should be subject to the same repetitive visual inspection intervals and pressure tests as stainless steel components. Repetitive tailpipe removal should apply to Inconel as well as stainless steel, and the interval should be accomplished every annual inspection. Proposed minimum exhaust component wall thickness of .025 inch is inappropriate. Exhaust repair stations should become involved only when repairs are necessary. Proposed repetitive 500-hour disassembly of slip joints is unnecessary and may cause more harm than good.
Engine mount beam inspection provision requires clarification.
Prohibition of certain weld repairs requires clarification. Furthermore, AOPA believes this method is the most reasonable way to address the airworthiness issues surrounding turbocharged twin Cessna aircraft without imposing significant economic hardship upon owners of affected aircraft. Additionally, the safety record of the past 30 months clearly demonstrates that twin Cessna exhaust system failures can be effectively prevented through a combination of regular and diligent visual inspections and pressure tests. Thank you for your time and consideration in this matter.