{"id":"F2006B03439","name":"AD/B767/85 Amdt 4 - MLG Outer Cylinder Aft Trunnion","slug":"ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42993,"registerId":"commonwealth-F2006B03439-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B767/85 Amdt 4 - MLG Outer Cylinder Aft Trunnion","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B767/85 Amdt 3 and issues the following 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.\n\n![](image.001.png)\n\nBoeing 767 Series Aeroplanes\n\nAD/B767/85\n\nAmdt 4\n\n  \nMLG Outer Cylinder Aft Trunnion 4/2002\n\nApplicability: Model 767 series aircraft with line numbers 001 through 605, on which the terminating action required by paragraph (e) of the Requirement 3 document has not been accomplished.\n\nRequirement: 1. Action in accordance with the technical requirements of FAA AD T95-20-51.\n\n    2. Action in accordance with the technical requirements of FAA AD 95-19-10 Amdt 39-9372.\n\n    3. Action in accordance with the technical requirements of FAA AD 2002-01-13 Amdt 39-12607.\n\nNote 1: Compliance with the requirements of Boeing Service Bulletin 767-32A0148 Revision 2, dated 30 November 2000, constitutes terminating action for the inspection requirements of this Directive.\n\nNote 2: Compliance in accordance with “Part 4-Terminating Action” of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-32A0192, dated 31 May 2001, constitutes terminating action for the inspection requirements of this Directive.\n\nCompliance: For Requirement 1: As specified in the Requirement Document with the initial inspection to be performed before 30 September 1995; until commencement of compliance with Requirement 3.\n\nFor Requirement 2: As specified in the Requirement Document; until commencement of compliance with Requirement 3.\n\nFor Requirement 3: As specified in the Requirement Document, with a revised effective date of 18 April 2002.\n\nThe compliance times remain unchanged for Requirements 1 and 2\\. This Airworthiness Directive becomes effective on 18 April 2002.\n\nBoeing 767 Series Aeroplanes\n\nAD/B767/85 Amdt 4 (continued)\n\nBackground: The FAA issued an AD in response to several reports of fractures of the outer cylinder aft trunnion due to stress corrosion cracking. Subsequent to the above reports, the FAA received an additional report of the collapse of the main landing gear on a Model 767-300 series aircraft. Investigation revealed that this latest fracture differed from those reported previously in that it initiated at the crossbolt hole, and additional inspections in an expanded area are now required.\n\nAmendment 1 required inspections to detect cracking and corrosion of the aft trunnion of the outer cylinder of the main landing gear, and various follow-on actions. It also provided for termination of the inspections by repairing the outer cylinder and installing new aft trunnion bushes.\n\nAmendment 2 clarified an inspection requirement of FAA AD 96-03-02 R1. Amendment 3 required implementation of the previously optional terminating action.\n\nAmendment 4 is issued in response to a new FAA AD which prohibits the use of a particular corrosion inhibiting compound during accomplishment of the terminating action.\n\nAmendment 3 of this Airworthiness Directive became effective on 30 January 1997\\. Amendment 2 of this Airworthiness Directive became effective on 20 June 1996.\n\nThe original issue of this Airworthiness Directive became effective on 30 September 1995.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 8 March 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 27 March 2002.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original 1995 directive addressed stress corrosion cracking in the main landing gear outer cylinder aft trunnion. Over four amendments (1995–2002), the scope expanded significantly: Amendment 1 added terminating action options; Amendment 2 clarified inspection requirements; Amendment 3 made previously optional terminating actions mandatory; and Amendment 4 (this version) added prohibitions on specific materials/chemicals used in repairs. The directive evolved from simple inspection requirements to a complex regime of phased inspections, mandatory terminating actions, and material prohibitions."},"complexity_factors":["Multiple nested compliance pathways: Requirements 1 and 2 remain active until Requirement 3 is commenced, creating overlapping compliance periods","Cross-references to three separate FAA Airworthiness Directives (T95-20-51, 95-19-10, and 2002-01-13) without reproducing their technical content","Conditional applicability based on serial number range (line numbers 001–605) AND exclusion of aircraft where terminating action already completed","Two different terminating action pathways referenced (Boeing Service Bulletin 767-32A0148 Rev 2 and Boeing Alert Service Bulletin 767-32A0192)","Amendment history spanning 7 years (1995–2002) with four amendments, requiring readers to understand cumulative changes","Technical aviation terminology requiring specialised knowledge (e.g., \"outer cylinder aft trunnion,\" \"crossbolt hole,\" \"corrosion inhibiting compound\")"],"plain_english_summary":"This AD mandates inspections and repairs on Boeing 767 main landing gear outer cylinder aft trunnions (line numbers 001–605) because stress-corrosion cracking has led to a gear collapse. It requires operators to follow the referenced FAA directives until a Boeing service-bulletin repair (terminating action) is completed. Effective 18 April 2002, the amendment also prohibits use of a specific corrosion-prevention chemical found to be problematic. This protects against catastrophic landing-gear failure."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Yes. Compared with the original AD (effective 30 September 1995) the scope was broadened and constrained: investigations required inspections over an expanded area after a new fracture initiation point was discovered (Background), and Amendment 4 adds a prohibition on using a specified corrosion‑inhibiting compound during the terminating action, altering acceptable repair methods and compliance choices (Amendment 4; Notes 1–2)."},"complexity_factors":["Cross‑reference to multiple FAA ADs (Requirement 1–3) rather than fully contained obligations, increasing dependence on external regulatory texts.","Termination options specified via Boeing Service Bulletins (Notes 1–2) create alternative compliance paths and require reading manufacturer instructions.","Applicability limited to specific aircraft line numbers 001–605 (Applicability) which requires operators to verify serial/line status.","Staggered and revised compliance timelines, including an initial inspection date (Requirement 1) and a revised effective date of 18 April 2002 (Compliance).","Amendment 4 adds a procedural prohibition (prohibits use of a particular corrosion inhibiting compound) which changes allowed repair methods (Background/Amendment 4).","Technical inspections target an expanded area after a later failure mode (crossbolt hole initiation), increasing inspection scope and technical judgement (Background).","Administrative layering from prior amendments (Amendments 1–3) and revocation of the prior AD creates tracking and record‑keeping burdens for operators and regulators.","Compliance depends on coordinating regulatory (FAA) and manufacturer (Boeing) materials, raising implementation and interpretation risks."],"plain_english_summary":"This Airworthiness Directive, issued by the CASA delegate, requires operators of Boeing 767 aeroplanes (line numbers 001–605) that have not completed the earlier terminating action to carry out inspections, follow‑on actions and the specified terminating repair or installation for the main landing gear outer cylinder aft trunnion, by following referenced FAA ADs and Boeing service bulletins. The AD is effective 18 April 2002. Operators pay for inspections, repairs and downtime; Amendment 4 also prohibits using a particular corrosion‑inhibiting compound during the terminating action in response to stress‑corrosion cracking and a crossbolt‑hole failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion","history":"/api/acts/ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion/history","analysis":"/api/acts/ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion/analysis","conflicts":"/api/acts/ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion/conflicts","importantCases":"/api/acts/ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion/important-cases","documents":"/api/acts/ad-b767-85-amdt-4-mlg-outer-cylinder-aft-trunnion/documents"}}