No good talking to Steve Swift ... he'll just send you on to me. In the first instance I'd worry more about the J2BDs. Possibly the worst piston engine in the world, and you are looking at 100K a side. Piper did the original fatigue assessment and it was they who put the life limits on it in accordance with the requirements from CASA. It was designed as a corporate aircraft, and Piper thought 13,000 hours good enough - they could have done better.. Nobody foresaw Reg 203 exempt ops and by 1989 (yes 28 years ago) there were time-x chieftains pushed up against fences everywhere. Come the pilots strike - everybody wanted a mod, and that was what gipps did. We moved it across from fatigue to Damage Tolerance and everybody (including Max Hazelton who I think had 20 plus) was happy. Sure you can get the AD rescinded just get piper to provide CASA with the relevant information. It is no different for Boeings or Pipers - what the manufacturer says goes unless you can find some poor underpaid bunny to recrank the numbers. And you will need a cuppla mill to do that. Mahindra no longer does the mod - mostly I suspect because of sentiments like the above. I'd have a long hard look for corrosion especially between the lower spar cap and the thick splice plate and study up on detonation