AD/LYC/98 - Push Rod Inner Diameter Scoring (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Lycoming Piston Engines

AD/LYC/98 Push Rod Inner Diameter Scoring 6/95 Applicability: All Textron Lycoming O-235 series engines detailed in Textron Lycoming Mandatory Service Bulletin No. 522.

Note: Only engines shipped from Textron Lycoming in the period 22 February 1993 to 2 September 1994 and O-235 engines fitted with new push rods, for whatever reason, since 22 February 1993 are affected.

Requirement: Inspect applicable engine push rods in accordance with Textron Lycoming Mandatory Service Bulletin No. 522.

Replace push rods identified as P/N 73806 with revision letters "V" or "W" before further flight.

Note: FAA Airworthiness Directive 95-03-10 refers.

Compliance: Effective 25 May 1995; unless previously accomplished and recorded by a certification in the engine log book, within 10 hours time in service or prior to 1 July 1995, whichever occurs first.

Background: This Directive requires the inspection of certain O-235 engines for fitment of suspect push rods. The requirement follows advice of the investigation of several O-235 engine failures. The investigation determined the failures to have initiated from scoring of the push rod tube inner diameter. The internal scoring was introduced during extrusion of the tube at the supplier.