AD/LYC/117 Lycoming Crankshaft Replacement (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Lycoming Piston Engines

AD/LYC/117 Lycoming Crankshaft Replacement 12/2006

Applicability:

Lycoming Engines (L)O-360, (L)IO-360, AEIO-360, O-540, IO-540, AEIO-540, (L)TIO-540, IO-580, and IO-720 series reciprocating engines listed by engine model number and serial number in Table 1, Table 2, Table 3, or Table 4 of Lycoming Mandatory Service Bulletin (MSB) 569A dated 11 April 2006, and those engines with crankshafts listed by crankshaft serial number in Table 5 of MSB 569A.

This AD is NOT applicable if the engine meets any of the following conditions, and the crankshaft has not been replaced since meeting the condition:

A.   Engines that are in compliance with:

i)     CASA AD/LYC/107 or Lycoming MSB No. 552 or MSB No. 553; or

ii)     CASA AD/LYC/112 or Lycoming MSB No. 566 or AD/LYC/115 or Lycoming MSB 566 Supplement 1; or

iii)    Lycoming MSB No. 569, or MSB No. 569A; or

B.    Lycoming Engines manufactured new, rebuilt, overhauled, or repaired the engine, or replaced the crankshaft in the engine before 01 March 1997, and the crankshaft has not been replaced since then; or

C.   Table 1, Table 2, Table 3, or Table 4 of Lycoming MSB No. 569A lists the engine serial number (SN), and Table 5 of MSB No. 569A does not list the crankshaft SN; or

D.   Lycoming engine model TIO-540-U2A with serial number (SN) L-4641-61A.

Requirement:

1.    If Table 5 of Lycoming MSB No. 569A dated 11 April 2006 lists the crankshaft SN, replace the affected crankshaft with a crankshaft that is not listed in Table 5 of MSB No. 569A.

2.    Do not install any crankshaft that has a SN listed in Table 5 of Lycoming MSB No. 569A into any engine.

Note:  FAA Airworthiness Directive 2006-20-09 amendment 39-14778 dated 29 September 2006 refers.

Compliance:

1.    At the earliest of the following, after the effective date of this AD:

i)     The time of the next engine overhaul as specified in Lycoming Engines Service Instruction No. 1009AS dated 25 May 2006; or

ii)     The next separation of the crankcase; or

iii)    No later than 12 years from the time the crankshaft first entered service or was last overhauled, whichever is later.

2.    After the effective date of this AD

This Airworthiness Directive becomes effective on 23 November 2006.

Background:

This AD results from reports of 23 confirmed failures of similar crankshafts in Lycoming Engines 360 and 540 series reciprocating engines.  CASA is issuing this AD to prevent failure of the crankshaft, which will result in total engine power loss, in-flight engine failure, and possible loss of the aircraft.

James Coyne
Delegate of the Civil Aviation Safety Authority

12 October 2006