68-21-03: Exhaust Tailpipe Assemblies

68-21-03 PIPER: Amendment 39-667. Applies to Model PA-23-250 and PA-E23-250 Aircraft Serial Nos. 27-2505 through 27-3858 that Incorporate AiResearch Turbosupercharged Lycoming IO-540-J4A5 or IO-540-C4B5 Engines Installed in accordance with Supplemental Type Certificate No. SA909WE or SA978WE, or in accordance with Piper Aircraft Corporation Drawing No. 32016. Compliance required within 10 hours of aircraft operations after the effective date of this Airworthiness Directive, unless previously accomplished. To preclude failures of the exhaust tailpipe assemblies, AiResearch P/N 286-P23-060-5 and P/N 286-P23-060-9: (a) Visually inspect both the left and right hand engine tailpipes for cracks or deformation. If a crack or deformation is found in either tailpipe, retire the affected tailpipe assembly and replace with a new tailpipe assembly of the same part number. (b) Visually inspect both the left and right hand engine tailpipes for sufficient clearance betweenthe tailpipes and the firewalls and between the tailpipes and the cowl flaps in accordance with AiResearch Aviation Service Company Service Bulletin No. 14.1.8 dated April 25, 1968, or later FAA approved revisions. If sufficient clearance does not exist, install AiResearch Kit P/N 301-P23-063 and adjust for sufficient clearance in accordance with the above service bulletin. This amendment becomes effective October 28, 1968.