COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Fokker F27 Series Aeroplanes
AD/F27/141 Main Landing Gear - Drag Stay Tubes 6/95
Applicability: All F27 aircraft with Dowty Aerospace Main Landing Gear Drag Stay assemblies P/N 200684001, 200261001, 200485001, 200684002, 200261002, 200485002,
200684003, 200261003 and 200485003 installed.
Requirement: 1. Ultrasonically inspect applicable assemblies to determine whether a straight or a stepped bore tube is installed. Inspect in accordance with Appendix A, paragraph 3 of Dowty Aerospace SB 32-82W or SB 32-169B as applicable.
Re-identify assemblies with a tube having:-
- a straight bore as P/N 200684004, 200261004 or 200485004 as appropriate,
b. a correctly blended radius as P/N 200684003, 200261003 or 200485003 as appropriate,
c. an incorrectly blended radius as P/N 200684002, 200261002 or 200485002 as appropriate.
Assemblies identified as P/N 200684004, 200261004 or 200485004 do not require further inspection.
2. Inspect Main Landing Gear Drag Stay assemblies re-identified as P/N 200684002, 200261002, 200485002, 200684003, 200261003 and 200485003 for cracking in accordance with Appendix A, paragraph 4 of Dowty Aerospace SB 32-82W or SB 32-169B.
Assemblies identified as P/N 200684003, 200261003 or 200485003 which have no crack indications do not require further inspection.
Re-identify assemblies identified as P/N 200684003, 200261003 or 200485003 with signal indications of less than 80% Full Screen Height (FSH) as 200684002, 200261002 or 200485002, as appropriate. Scrap assemblies with signal indications of 80% FSH or more.
3. Re-work assemblies 200684002, 200261002 and 200485002 in accordance with Appendix B of Dowty SB 32-82W Revision 1 or SB 32-169B Revision 1 as applicable. Inspect in accordance with Appendix A, paragraph 4 of Dowty Aerospace SB 32-82W or SB 32-169B as appropriate.
Re-worked assemblies P/N 200684002, 200261002 and 200485002 which have no crack indications shall be re-identified as P/N 200684003, 200261003, and 200485003 as appropriate; these assemblies do not require further inspection.
Scrap assemblies with any crack indications.
Note: RLD AD 93-169(A) refers.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Compliance: 1. Initially inspect and re-identify in accordance with Requirement 1 before 22 June 1995.
2. Initially inspect in accordance with Requirement 2 before 22 June 1995.
Re-inspect assemblies identified as P/N 200684002, 200261002 and 200485002 for cracking at intervals not to exceed 1500 flights until reworked in accordance with Requirement 3.
3. Re-work in accordance with Requirement 3 at, or before, the next scheduled Main Landing Gear overhaul after 25 May 1995, or before installation on an aircraft, whichever occurs later.
Background: One instance of a failed drag stay tube has been reported. Failure caused the landing gear to collapse and was attributed to a crack originating at an incorrectly machined step on the tube interior. This AD will ensure that all such tubes are identified and, if possible, reworked to an acceptable configuration.
Overview
The Civil Aviation Regulations 1998, enacted by the Australian Parliament, establish the legal framework for the regulation of civil aviation safety, including the issuance of airworthiness directives. One such directive, AD/F27/141, was introduced to address the problem of potential failure in the drag stay tubes of Fokker F27 Series aeroplanes with specific Dowty Aerospace Main Landing Gear Drag Stay assemblies. The directive was issued by the Civil Aviation Safety Authority to ensure that all such tubes are identified and, if possible, reworked to an acceptable configuration, following a reported instance of a failed drag stay tube that caused the landing gear to collapse. The policy objective is to enhance the safety of civil aviation by mitigating the risk of failure in these critical components.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all Fokker F27 series aeroplanes equipped with Dowty Aerospace Main Landing Gear Drag Stay assemblies bearing specific part numbers. This directive is mandated by the Commonwealth of Australia and applies nationally across all states and territories. It is pertinent to operators of the Fokker F27 aircraft within Australia, ensuring that the specified assemblies meet airworthiness standards to prevent failures such as the collapse of the landing gear. The directive mandates specific inspections and rework procedures to identify and address potential defects in the drag stay tubes, ensuring safety and compliance with aviation standards. There are no stated exclusions or exemptions in the directive, and compliance must be strictly adhered to by all affected aircraft operators. Further specifications and detailed procedures are provided in the Dowty Aerospace Service Bulletins referenced in the directive.
Key Provisions
The Civil Aviation Regulations 1998, specifically in Part 39 - 105, includes an airworthiness directive (AD/F27/141) concerning Fokker F27 Series Aeroplanes and their main landing gear drag stay tubes. The directive applies to all F27 aircraft equipped with specified Dowty Aerospace Main Landing Gear Drag Stay assemblies (section 6/95). The key requirement outlined in the directive is the ultrasonic inspection of the assemblies to determine the bore configuration (straight or stepped) and subsequent re-identification based on the findings (section 1). Depending on the results, assemblies are re-identified with new part numbers. Additionally, assemblies identified as having an incorrectly blended radius must be inspected for cracks (section 2). Those with no crack indications are re-identified, while those with significant crack indications must be scrapped. Any assemblies identified as needing rework must be re-worked and inspected again, with those showing no cracks being re-identified, and those with any crack indications being scrapped (section 3).
The AD imposes specific obligations on the parties involved, primarily those operating Fokker F27 aircraft with the specified drag stay assemblies. These obligations include conducting the initial inspection and re-identification of the assemblies before a specified date, performing periodic inspections at intervals not exceeding 1500 flights for certain assemblies, and ensuring that any necessary rework is carried out at the next scheduled main landing gear overhaul or before installation on an aircraft (section Compliance). Failure to comply with these obligations can result in serious safety risks, given the potential for landing gear failure and associated hazards.
The directive does not explicitly state penalties for non-compliance, but given its nature and the critical safety implications, non-compliance could lead to severe consequences. These may include grounding of the aircraft, enforcement actions by the Civil Aviation Safety Authority, and potentially, civil or criminal liability for any accidents or incidents resulting from non-compliance. The potential penalties could encompass fines, operational restrictions, or other regulatory sanctions as deemed appropriate by the relevant authorities.