76-06-09: Engine Exhaust System

76-06-09 PIPER: Amendment 39-2559 as amended by amendment 39-3325. Applies to Piper Model PA-31P airplanes. Compliance required as indicated unless already accomplished. To preclude failure of the engine exhaust system installed on Model PA-31P airplanes, accomplish the following: (a) On airplanes serial numbers 31P-1 through 31P-7730003 within 50 hours after the effective date of this amendment, and every 50 hours thereafter, visually inspect turbocharger exhaust V-band couplings, vibration isolators and support brackets (if installed) for cracks, looseness, and distortion. Any part found cracked or distorted shall be replaced prior to further flight. (b) On airplane serial numbers 31P-1 through 31P-7630001 and on 31P-7630003 within 50 hours time in service after the effective date of this AD perform exhaust pipe slip joint modification in accordance with Lycoming Service Bulletin 393A or an equivalent approved alteration. (c) On airplanes serial numbers31P-1 through 31P-7630009 within 50 hours time in service after the effective date of this AD install bracket and clamp assembly, Piper Kit No. 760 974, in accordance with Piper Service Bulletin 462A or an equivalent approved alteration. (d) On airplanes serial numbers 31P-1 through 31P-7730003 the repetitive inspections of paragraph (a) shall be accomplished until the replacement one-piece turbine tailpipe clamp coupling P/N 556053 is installed in accordance with the "Instructions" sheet in Piper Service Bulletin No. 534 and vibration isolators installed in accordance with Piper Service Bulletin No. 492. NOTE: When replacing the turbine tailpipe clamp coupling, preload the tailpipe against the turbine flange as specified in Piper Service Bulletin Nos. 534 and 462A. (e) Aircraft may be flown to a base where the maintenance required by this airworthiness directive is to be performed per FAR's 21.197 and 21.199. (f) The Chief, Engineering and Manufacturing Branch, FAA Eastern Region may adjust the inspection interval specified in this airworthiness directive upon request of an owner or operator submitted with substantiating data through an FAA maintenance inspector. All equivalent alterations or parts must be approved by the said Branch Chief. (Piper Service Bulletin No. 430 also pertains to this subject.) Amendment 39-2559 was effective March 31, 1976. This amendment 39-3325 is effective October 31, 1978.