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
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.
AD/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.
The original issue of this Airworthiness Directive became effective on 23 July 1992.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 20 August 2001
The above AD is notified in the Commonwealth of Australia Gazette on 12 September 2001.
Overview
The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA), include a comprehensive framework for maintaining the airworthiness of aircraft operating within Australia. One significant piece of legislation within this framework is the Airworthiness Directive (AD) DHC-8/21 Amendment 1 issued in 2001. This directive was enacted to address the identified risk of engine rear mount strut failures in Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes, which could potentially compromise the structural integrity of the engine/nacelle installation. The directive mandates detailed visual inspections and the replacement of affected struts to ensure the continued safety and airworthiness of the specified aircraft models. The policy objective behind this AD is to mitigate the risk of in-flight failures by ensuring that identified structural weaknesses are addressed promptly and effectively.
Scope and Application
The Airworthiness Directive (AD) issued under the Civil Aviation Regulations 1998, specifically pertains to Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes. It applies to DHC-8 aircraft, including Models 102, 103, 106, 201, 202, 301, 311, 314, and 315, with serial numbers ranging from 003 through 517, that are equipped with specific engine rear mount struts. The directive mandates a detailed visual inspection for cracks in the affected engine rear mount strut assemblies on both the left and right engine nacelles. In the event of discovering cracked struts, they must be replaced before any further flight. Additionally, replacing both engine rear mount struts in a nacelle with new machined struts terminates the repetitive inspection requirements for that nacelle. The AD applies within the jurisdictional reach of the Commonwealth of Australia and is enforced by the Civil Aviation Safety Authority (CASA). The AD becomes effective on 4 October 2001, and compliance is required initially within 1,000 hours of time in service since new or within 250 hours time in service after 4 October 2001, whichever occurs later, and subsequently, at intervals not exceeding 250 hours time in service.
Key Provisions
This Airworthiness Directive (AD) applies to certain models of Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes with specific serial numbers and engine rear mount struts, as detailed in the applicability section. The AD mandates a detailed visual inspection for cracks in the engine rear mount strut assemblies on both the left and right engine nacelles. If any cracks are found, the struts must be replaced before further flight. Additionally, if both engine rear mount struts in a nacelle are replaced with new machined struts, part number 87110047-001, the repetitive inspection requirements for that nacelle will cease. This cessation of repetitive inspections does not affect the operator’s approved maintenance program for these struts.
The AD imposes specific obligations on the operators of the affected aircraft. They must conduct the initial inspection within 1,000 hours of time in service since new or within 250 hours after 4 October 2001, whichever is later, unless already performed. Subsequent inspections must be carried out at intervals not exceeding 250 hours. The installation of one new machined strut in a nacelle extends the inspection interval to 500 hours for that nacelle. These requirements are designed to ensure the safety and airworthiness of the aircraft by preventing failures of the engine rear mount struts.
Failure to comply with this AD can have serious consequences. The AD does not explicitly state penalties for non-compliance, but non-compliance with airworthiness directives can lead to severe civil or criminal penalties under the Civil Aviation Act 1988 and the Civil Aviation Regulations 1998. Such penalties may include fines and potential grounding of the aircraft, which can significantly impact the operations of the airline. The exact penalties would depend on the specific circumstances of the non-compliance and the determination of the Civil Aviation Safety Authority (CASA).