AD/LYC/102 Amdt 3 Crankshaft Internal Inspection (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/LYC/102 Amdt 2 and issues the following 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/102 Amdt 3 Crankshaft Internal Inspection 2/2007

Applicability:

Lycoming O-320 and O-360 series engines as detailed in Lycoming Mandatory Service Bulletin (MSB) No. 505B; and not incorporating a front bore protective coating as detailed in Lycoming Service Bulletin No. 530 at any revision status.

Note 1:  Engines applicable are engines fitted with hollow front bore crankshafts and installed in aircraft propelled by fixed pitch propellers.

Requirement:

1.    Carry out an internal inspection of the crankshaft front bore for evidence of corrosion in accordance with Lycoming MSB No. 505B or later FAA approved revisions.

If there is no evidence of pitting corrosion in the front bore, no further action is required until the next inspection as detailed in the compliance requirements of this Directive.

2.    If in carrying out the internal inspection in accordance with Requirement 1 of this Directive there is evidence of pitting corrosion in the front bore:

a.     Carry out a Fluorescent Penetrant Inspection (FPI) in accordance with the FPI procedures detailed in Lycoming MSB No. 505B or later FAA approved revisions.

b.    Remove any evidence of pitting corrosion in accordance with approved data (procedures approved by CAR 35 authorised persons are considered acceptable for the purpose of this AD) or remove the crankshaft from service.

c.     If in carrying out the FPI, a crankshaft is found to be cracked, remove the crankshaft from service.

3.    Spare crankshafts: Carry out an internal inspection of the crankshaft front bore for evidence of corrosion in accordance with MSB No. 505B or later FAA approved revisions; and

a.     Remove any evidence of pitting corrosion in accordance with approved data (procedures approved by CAR 35 authorised persons are considered acceptable for the purpose of this AD); and

b.    Carry out a Magnetic Particle Inspection of the crankshaft front bore in accordance with approved data; and

c.     Apply a protective coating in accordance with Lycoming MSB No. 530 dated 1 December 1997 or later FAA approved revisions.

Note 2:  The application of Urethabond 104 to the inner bore of the crankshaft and confirmed by stamping of the letters "PID" on the outside diameter of the propeller flange in accordance with Lycoming MSB No. 530 or later FAA approved revisions constitutes terminating action to the inspection requirements of this AD.

Note 3:  FAA Airworthiness Directive 98-02-08 amendment 39-10291 refers.

Compliance:

Requirement 1:

Engines with a time in service (TIS) since new, remanufacture or overhaul, of greater than 1,000 hours or 10 years:

within 100 hours TIS or 12 months from effective date of this AD or at next removal of the crankshaft from the engine, whichever occurs first, unless previously accomplished; and

repetitively thereafter at intervals not to exceed 5 calendar years.

Engines with a TIS since new, remanufacture or overhaul of less than 1,000 hours and 10 years:

prior to exceeding 1,100 hours TIS or 11 years TIS or at next removal of the crankshaft from the engine, whichever occurs first, unless previously accomplished; and

repetitively thereafter at intervals not to exceed 5 calendar years.

Requirement 2:

a.     Before further flight.

b.    Within 100 hours time in service.

c.     Before further flight.

Requirement 3(a), 3(b) and 3(c):

Prior to installation of a crankshaft in an engine, unless previously accomplished.

This Amendment becomes effective on 15 February 2007.

Background:

The AD was originally issued to require the inspection of hollow front bore crankshafts fitted with fixed pitch propellers.  The requirement addressed CAA (UK) advice of two crankshaft failure events in flight.  Crankshaft failure can result in engine failure, propeller separation, forced landing, and possible damage to the aircraft.

The current Amendment clarifies compliance requirements at the request of the industry and makes reference to the latest revision(s) of the service documents.

The Amendment 2 of this AD was issued to include CAR 35 authorised persons in designing and approving inspection and repair schemes.  Amendment 2 became effective on 8 October 1998.

The Amendment 1 of this AD addressed the concerns raised by the industry by interpreting the compliance requirements and making necessary changes.  Amendment 1 became effective on 18 June 1998.

The original issue of this Airworthiness Directive became effective on 14 May 1998.

James Coyne
Delegate of the Civil Aviation Safety Authority

4 January 2007