{"id":"F2006B09761","name":"AD/F28/24C - Cargo Doors - Door Lock Mechanism - Inspection and Modification","slug":"ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54634,"registerId":"commonwealth-F2006B09761-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/24C - Cargo Doors - Door Lock Mechanism - Inspection and Modification","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nFokker F28 Series Aeroplanes\n\nAD/F28/24C Cargo Doors - Door Lock NK Mechanism - Inspection and Modification\n\nApplicability: All models with S/Nos. 11003 to 11993.\n\nRequirement: 1. Inspect door locking mechanism as per Part 2 of SB F28/52-53 by aircraft S/No. as referenced in applicable SB.\n\n    2. Modify door locking mechanism by fitting a reinforced safety catch and stop assembly, detailed in SB F28/52-51 on aircraft with S/nos. referenced in that service bulletin.\n\n    3. Further modify door locking mechanism by fitting a revised switch operating mechanism as detailed in SB F28/52-49 on aircraft with S/No. referenced in that service bulletin.\n\n    4. Further modify the cargo door locking mechanism by reinforcing the door locking handle access panel as detailed in SB F28/52-81 on aircraft with S/Nos. and cargo door configurations referenced in that SB. RLD AD A118/77 also refers.\n\nCompliance: For Para. 1 \\- Before 1 September 1974.\n\nFor Para. 2 \\- Before 1 January 1975.\n\nFor Para. 3 \\- Before 1 January 1975.\n\nFor Para. 4 \\- Before 15 July 1978.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"The directive consolidates an initial inspection requirement with subsequent mandatory hardware modifications. Requirements now include staged inspection (Para. 1) plus three distinct modification actions (Paras. 2–4) with separate deadlines, expanding the operational and maintenance obligations compared with a single inspection-only measure (see Requirement Paras. 1–4 and corresponding Compliance dates)."},"complexity_factors":["Serial-number limited applicability creates per-aircraft variation in required work (Applicability: All models with S/Nos. 11003 to 11993).","Multiple, staged mandatory actions referencing different service bulletins increase administrative and technical coordination (Requirement Paras. 1–4 reference SB F28/52-53, SB F28/52-51, SB F28/52-49, SB F28/52-81).","Different compliance deadlines for each action impose scheduling and operational constraints (Compliance: separate dates for Para. 1, Paras. 2–3, and Para. 4).","Requirement 4 conditions work on particular cargo door configurations, creating variable scope across the fleet (Requirement Para. 4 references S/Nos. and cargo door configurations in SB F28/52-81).","Cross-reference to a prior AD introduces legacy compliance history to reconcile (Requirement Para. 4: RLD AD A118/77 also refers).","Operators must source and follow specific service bulletin detail to perform mandated modifications, creating technical dependency on SB content (Requirement Paras. 1–4 reference specific SBs)."],"plain_english_summary":"This airworthiness directive requires owners/operators of Fokker F28 aeroplanes (S/Nos. 11003–11993) to inspect the cargo door lock mechanism and carry out a sequence of mandated hardware modifications. Operators must complete specified inspections and fit reinforced catches, a revised switch-operating mechanism and a strengthened access panel by set deadlines to correct identified door-lock safety issues."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a straightforward, targeted safety directive focused specifically on Fokker F28 cargo door mechanisms. It has not expanded beyond its original purpose of addressing a known airworthiness issue with door locks on this specific aircraft type."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 specific technical requirements, each referencing external Service Bulletins (SBs) rather than detailing procedures in the text itself","No defined terms section — relies on standard aviation terminology","Simple conditional structure: if your aircraft is in the serial number range, you must do these four things by these four dates","No nested exceptions or complex cross-referencing within the instrument itself","Single applicability criterion (serial number range)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of Fokker F28 aircraft (serials 11003–11993) to inspect and modify cargo door locking systems to ensure doors secure and switches/reporting function correctly. It affects airlines and charters flying these jets and is mandatory: aircraft cannot legally fly until compliance.\n\nIt matters because faulty cargo locks can cause in‑flight door opening, rapid decompression, or loss of the door, posing serious safety risks."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification","history":"/api/acts/ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification/history","analysis":"/api/acts/ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification/analysis","conflicts":"/api/acts/ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification/important-cases","documents":"/api/acts/ad-f28-24c-cargo-doors-door-lock-mechanism-inspection-and-modification/documents"}}