Commonwealth legislation

AD/DHC-8/21 Amdt 1 - Engine Rear Mount Strut

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

4/10 complexity

This Airworthiness Directive requires operators of specified Bombardier (De Havilland) DHC‑8 models and serial numbers fitted with certain engine rear‑mount struts to carry out detailed visual inspections for cracks and to replace any cracked struts before further flight. Installing the new machined strut part (87110047‑001) changes inspection intervals or, if both struts in a nacelle are replaced, ends the repetitive inspections for that nacelle. It matters because fractures were reported originating at rosette welds, so operators must change inspection and maintenance practices and bear inspection/repair costs.

JSON API

Deep dive

Want the full deep dive?

Zoe can write the in-depth analysis on top of the summary above: how it works, who it affects and what each part actually does.

Current sections

Direct links to the current provisions in AD/DHC-8/21 Amdt 1 - Engine Rear Mount Strut.

AD/DHC-8/21 Amdt 1 - Engine Rear Mount Strut

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source
View image in the official source
Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AIRWORTHINESS DIRECTIVE

View image in the official source

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 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.

View image in the official sourceAD/DHC-8/21

Amdt 1

Engine Rear Mount Strut 10/2001

Applicability: DHC-8 aircraft, Models 102, 103, 106, 201, 202, 301, 311, 314, and 315, with serial numbers 003 through 517; equipped with engine rear mount struts, part numbers 87110016-003, -005, -007, -009, -011, or 8DK1763-001.

Requirement: Perform a detailed visual inspection for cracks in the affected engine rear mount strut assemblies listed in the Applicability part of this Directive, on both the left and right engine nacelles.

Replace cracked struts before further flight.

Replacement of both engine rear mount struts in a nacelle with the new machined struts, part number 87110047-001, terminates the repetitive inspection requirements of this Directive for that nacelle only.

Note 1: Termination of the repetitive inspections as specified in this Directive does not alter the operator’s approved maintenance program for these rear mount struts.

Note 2: Transport Canada AD CF-2001-20 refers.

Compliance: Initially, within 1,000 hours time in service since new or within 250 hours time in service after 4 October 2001, whichever occurs later, unless already accomplished.

Subsequently, repeat at intervals not to exceed 250 hours time in service.

The installation of one new machined strut, part number 87110047-001, in a nacelle, increases the repeat inspection interval to 500 hours time in service for that nacelle only.

This Amendment becomes effective on 4 October 2001.

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

Background: There have been five reported failures of the engine rear mount strut. Investigation has determined that the fracture initiated at one of the rosette welds on the shank of the strut just above the bearing where full weld penetration was not achieved.

Amendment 1 is issued in response to a new Transport Canada AD which was prompted by reports that new and reworked struts required by the previous issue of this Directive, continued to fail. Failure of the engine rear mount strut would result in a degradation of the integrity of the engine/nacelle installation.

View image in the official sourceThe original issue of this Airworthiness Directive became effective on 23 July 1992.

View image in the official source

David Alan Villiers

Delegate of the Civil Aviation Safety Authority 20 August 2001

View image in the official source

The above AD is notified in the Commonwealth of Australia Gazette on 12 September 2001.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/DHC-8/21 Amdt 1 - Engine Rear Mount Strut

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AIRWORTHINESS DIRECTIVE

AD/DHC-8/21

Amdt 1

Engine Rear Mount Strut 10/2001

Replace cracked struts before further flight.

Note 1: Termination of the repetitive inspections as specified in this Directive does not alter the operator’s approved maintenance program for these rear mount struts.

Note 2: Transport Canada AD CF-2001-20 refers.

Compliance: Initially, within 1,000 hours time in service since new or within 250 hours time in service after 4 October 2001, whichever occurs later, unless already accomplished.

Subsequently, repeat at intervals not to exceed 250 hours time in service.

The installation of one new machined strut, part number 87110047-001, in a nacelle, increases the repeat inspection interval to 500 hours time in service for that nacelle only.

This Amendment becomes effective on 4 October 2001.

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY