{"id":"F2006B08490","name":"AD/CF6/52 - Thrust Reverser - Inspection","slug":"ad-cf6-52-thrust-reverser-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51182,"registerId":"commonwealth-F2006B08490-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor 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 CASR 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\nGeneral Electric Turbine Engines \\- CF6 Series","sortOrder":0},{"sectionNumber":"AD/CF6/52 Thrust Reverser - Inspection 8","sectionType":"part","heading":"AD/CF6/52 Thrust Reverser - Inspection 8/2003","content":"# AD/CF6/52 Thrust Reverser \\- Inspection 8/2003\n\nApplicability: General Electric Company (GE) CF6-80E1 series turbofan engines installed on, but not limited to, Airbus Industrie A330 series aeroplanes.\n\nRequirement: 1. For engines that do not have improved double P-seal configuration introduced by Middle River Aircraft Systems (MRAS) service bulletin (SB) 78-5037, original issue or Revision 1, inspect and check each fan thrust reverser half in accordance with 2.B., 2.C., and 2.D. of the Accomplishment Instructions of MRAS alert service bulletin (ASB) 78A5043, Revision 1, dated 22 January 2002.\n\n    2. Repeat Requirement 1 inspection and check.\n\n    3. For engines that do have improved double P-seal configuration introduced by MRAS SB 78-5037, original issue or Revision 1:\n\n    inspect and check each fan thrust reverser half in accordance with 2.B., and\n\n2.C. of the Accomplishment Instructions of MRAS ASB 78A5043, Revision 1, dated 22 January 2002.\n\n    b. check each fan thrust reverser half in accordance with 2.D. of the Accomplishment Instructions of MRAS ASB 78A5043, Revisio n 1, dated 22 January 2002.\n\n    4. Repeat Requirement 3(a) inspection and check.\n    5. Repeat Requirement 3(b) inspection and check.\n\nNote: FAA AD 2002-10-08 Amdt 39-12754 refers.\n\nCompliance: For Requirement 1: Before exceeding 7,000 flight hours time-since-new (TSN) or 1,000 flight hours time- in-service (TIS) whichever occurs later after the effective date of this Directive.\n\nFor Requirement 2: At intervals not to exceed 7,000 flight hours TIS since last inspection or check.\n\nFor Requirement 3(a): Before exceeding 25,000 flight hours TSN or 1,000 flight hours TIS whichever occurs later after the effective date of this Directive.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard single-issue Airworthiness Directive focused specifically on thrust reverser inspections for one engine series. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Multiple conditional branches based on engine modification status (improved double P-seal configuration vs. original configuration)","Cross-references to external technical documents (MRAS service bulletins ASB 78A5043 and SB 78-5037) without reproducing their content","Nested compliance timelines with 'whichever occurs later' conditional logic","Five separate numbered requirements with interdependent repeat intervals","Technical aviation terminology requiring specialised knowledge (TSN/TIS flight hour calculations, P-seal configurations, thrust reverser halves)","Reference to foreign regulatory instrument (FAA AD 2002-10-08) for additional context"],"plain_english_summary":"This safety order requires airlines and maintenance organizations operating Airbus A330s with General Electric CF6‑80E1 engines to inspect thrust reversers to prevent failures that could jeopardize safe landings. It mandates periodic inspections, with different inspection timing and methods depending on whether engines have the improved seal design, and ties to an FAA action—part of coordinated international aviation safety oversight."},"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD addresses a narrowly defined airworthiness issue (inspection of thrust reverser P‑seals on GE CF6‑80E1 engines) and prescribes corrective inspections and checks using MRAS service documents. There is no evident expansion beyond that technical safety purpose in this text: it does not broaden to other engine models, nor create unrelated regulatory obligations. The AD incentivises a retrofit (MRAS SB 78‑5037) by reducing initial inspection frequency for engines with the modification, but that is a targeted technical trade‑off rather than a scope expansion. Note: the AD's wording leaves some procedural timing ambiguous (see Complexity Factors), but this is an implementation detail rather than an enlargement of policy scope."},"complexity_factors":["Two mutually exclusive configuration branches (engines with and without the MRAS improved double P‑seal) with different actions and timing","Multiple requirements (Requirements 1–5) with repeat inspections","Dependence on three external documents (MRAS ASB 78A5043 Rev 1; MRAS SB 78‑5037; FAA AD 2002‑10‑08) for procedural and technical detail","Use of time metrics requiring record‑keeping (TSN = time‑since‑new; TIS = time‑in‑service) and \"whichever occurs later\" timing logic","Incomplete/ambiguous compliance text: the AD sets explicit timing for Requirement 1, 2 and 3(a) but omits clear repeat intervals or timing for Requirement 3(b) and for Requirements 4 and 5 in the Compliance paragraph","Short instrument length but technical dependence on specialised maintenance procedures (adds practical complexity)","Ambiguous scope phrase 'installed on, but not limited to, Airbus A330 series' which requires operators to determine applicability to other aircraft types"],"plain_english_summary":"**What this instrument does (mechanics)\n\n- Requires inspections of the fan thrust reverser halves on General Electric CF6-80E1 turbofan engines. The inspections must be carried out exactly as set out in the Middle River Aircraft Systems (MRAS) Alert Service Bulletin (ASB) 78A5043 Revision 1 (22 January 2002).  \n- Distinguishes two engine configurations: (A) engines that do NOT have the \"improved double P‑seal\" introduced by MRAS Service Bulletin (SB) 78‑5037, and (B) engines that DO have that improved P‑seal. Different inspection timing and procedures apply to the two groups (see below).  \n- Requires repeat (periodic) inspections after the initial check. The AD also cross‑refers FAA AD 2002‑10‑08.\n\nWho must act and who pays\n\n- Aircraft operators and maintenance organisations responsible for aeroplanes fitted with GE CF6‑80E1 engines must perform the inspections and any corrective work that the MRAS ASB requires.  \n- The cost of inspections, downtime, and any repairs or parts (including retrofits such as the improved double P‑seal) is borne by the operator or aircraft owner.\n\nWhy the regulator issued it (claimed purpose)\n\n- The AD states it corrects an identified \"unsafe condition\" in the thrust reverser P‑seal area. The explicit purpose (as stated in the AD) is to detect and correct defects that could lead to thrust reverser malfunction. That claim should be read against the concrete requirements below.\n\nWhat the AD requires (operational detail)\n\n- For engines without the MRAS improved double P‑seal (SB 78‑5037 not embodied):  \n  - Perform the inspection/check required by paragraphs 2.B, 2.C and 2.D of MRAS ASB 78A5043 Rev 1. (See Requirement 1.)  \n  - Initial timing: complete the inspection before exceeding 7,000 flight hours time‑since‑new (TSN) or 1,000 flight hours time‑in‑service (TIS), whichever occurs later, measured from the AD's effective date.  \n  - Repeat interval: at intervals not to exceed 7,000 flight hours TIS since the last inspection. (See Requirement 2 and the Compliance section.)\n\n- For engines with the MRAS improved double P‑seal (SB 78‑5037 embodied):  \n  - Perform the inspections/checks required by paragraphs 2.B and 2.C of MRAS ASB 78A5043 Rev 1 (Requirement 3(a)).  \n  - Perform the check required by paragraph 2.D of the same ASB (Requirement 3(b)).  \n  - Initial timing (for Requirement 3(a)): before exceeding 25,000 flight hours TSN or 1,000 flight hours TIS, whichever occurs later, after the AD's effective date.  \n  - The AD text lists separate \"repeat\" items (Requirements 4 and 5) for each sub‑check, but the Compliance paragraph does not explicitly state the repeat intervals for 3(a) and 3(b); operators must therefore follow the MRAS ASB and CASA/FAA guidance to confirm periodicity.\n\nHow this changes behaviour and incentives\n\n- Operators are required to inspect and, where necessary, repair or replace thrust reverser components to meet airworthiness standards.  \n- There is a clear retrofit incentive: installing the improved double P‑seal (MRAS SB 78‑5037) pushes back the first required inspection from 7,000 TSN to 25,000 TSN (for at least part of the inspection regime), which reduces inspection frequency/cost for operators who fit the modification.  \n- The AD increases maintenance workload and scheduling constraints for operators of affected engines; it places the compliance and cost burden on them (not on the regulator or manufacturer).\n\nImplementation, compliance and risk considerations\n\n- The AD relies on prescriptive external documents (MRAS ASB 78A5043 Rev 1 and MRAS SB 78‑5037) for detailed steps. Operators must have access to and follow those service documents.  \n- The Compliance section omits explicit repeat intervals for Requirement 3(b) and does not restate repeat intervals for Requirements 4 and 5. That gap creates an implementation risk: maintenance planners must consult the MRAS ASB and the FAA AD referenced to confirm the correct periodicity.  \n- The AD uses standard flight‑time metrics (TSN and TIS). Proper maintenance records are required to determine compliance timing.  \n- There may be parts, shop capability and scheduling costs if inspections reveal wear or damage that requires repair or replacement. Lead times for parts or shop visits may affect aircraft availability.\n\nAdministrative actors and discretion\n\n- The CASA delegate issues and enforces the Directive; operators must plan and record compliance. The AD prescribes mandatory actions (inspections and checks) rather than discretionary guidance. Discretion lies mainly in scheduling within the stated intervals and in deciding to adopt the MRAS SB modification (which changes inspection timing).\n\nConcrete trade‑offs and opportunity costs\n\n- Installing the MRAS improved P‑seal imposes retrofit cost and downtime but reduces inspection frequency; operators will weigh retrofit cost against recurring inspection and repair costs.  \n- Failure to comply risks regulatory action and continued operations with an identified potential unsafe condition; complying imposes direct maintenance costs and possible operational disruption.\n\nSources the AD relies on (operator must consult these)\n\n- MRAS Alert Service Bulletin 78A5043 Rev 1 (22 January 2002) — contains the step‑by‑step inspection and check instructions.  \n- MRAS Service Bulletin 78‑5037 (original or Revision 1) — describes the improved double P‑seal modification.  \n- FAA AD 2002‑10‑08 (referenced) — for related or corroborating mandatory actions.\n\nPractical note for operators\n\n- Before scheduling work, obtain MRAS ASB 78A5043 Rev 1 and MRAS SB 78‑5037, confirm which inspections apply to each engine based on whether the improved P‑seal is fitted, and consult the FAA AD for any clarifying compliance intervals. Keep accurate TSN/TIS records to demonstrate compliance.\n\n"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-52-thrust-reverser-inspection","history":"/api/acts/ad-cf6-52-thrust-reverser-inspection/history","analysis":"/api/acts/ad-cf6-52-thrust-reverser-inspection/analysis","conflicts":"/api/acts/ad-cf6-52-thrust-reverser-inspection/conflicts","importantCases":"/api/acts/ad-cf6-52-thrust-reverser-inspection/important-cases","documents":"/api/acts/ad-cf6-52-thrust-reverser-inspection/documents"}}