1AD/DHE/18 Amdt 5 - Tapered Crankshaft Inspection

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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De Havilland Piston Engines

AD/DHE/18

Amdt 5

Tapered Crankshaft Inspection 7/98

Applicability: Gipsy Major series engines fitted with a tapered crankshaft Requirement: 1. Insitu ultrasonic inspection:

In accordance with a procedure approved by the Authority, carry out an ultrasonic inspection of the crankshaft in the area forward of the thrust bearing flange.

2. Crankshaft inspection \- Pre Mod G2495 crankshafts:

(a) In accordance with a procedure approved by the Authority, carry out an ultrasonic inspection of the crankshaft in the area forward of the thrust bearing flange , and

(b) carry out a magnetic particle inspection of the entire crankshaft utilising the wet continuous technique applied in a manner that both longitudinal and circumferential cracking will be detected, CAO 108.8 Appendix 1 refers.

3. Crankshaft inspection \- Post Mod G2495 crankshafts:

(a) Remove the Mod G2495 thrust bearing location nut sleeve, and

(b) carry out a magnetic particle inspection of the entire crankshaft utilising the wet continuous technique applied in a manner that both longitudinal and circumferential cracking will be detected, CAO 108.8 Appendix 1 refers.

Compliance: Effective 18 June 1998:

Insitu ultrasonic inspection: Unless previously carried out;

(a) within 25 hours time in service or at the next maintenance release inspection, whichever occurs first, and then

(b) at 45 to 50 hours time in service following an inspection in accordance with Compliance requirement 1 (a).

Note 1: In service experience since the issue of AD/DHE/18 Amdt. 4 indicates the airworthiness of Gipsy Major tapered crankshafts in service can be reasonably established with two ultrasonic inspections. Therefore, engines in service which have already had two ultrasonic inspections of the tapered crankshaft, adequately satisfy Requirement 1 of this directive. No further insitu ultrasonic inspections are required.

2. Crankshaft inspection - Pre Mod G2495 crankshafts: Prior to installation of the crankshaft in an engine.

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

3 Crankshaft inspection - Post Mod G2495 crankshafts. Prior to installation of the crankshaft in an engine.

This amendment becomes effective on 18 June 1998.

Background: This directive was originally issued to require a visual and a magnetic particle inspection (MPI) of the tapered crankshaft in the area forward of the thrust bearing flange. Amendment 4 replaced the visual inspection with repetitive insitu ultrasonic inspections. In service experience since the issue of Amdt. 4 has indicated the airworthiness of tapered crankshafts in service can be satisfactorily determined by two consecutive, insitu, ultrasonic inspections. In response, this amendment limits the insitu ultrasonic inspection requirement to two consecutive inspections.