{"id":"F2006B02989","name":"AD/B737/89 - Main Deck Cargo Door - Existing Frame to Lower Sill Tie-Down","slug":"ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42348,"registerId":"commonwealth-F2006B02989-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/89 - Main Deck Cargo Door - Existing Frame to Lower Sill Tie-Down","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)  \nBoeing 737 Series Aeroplanes\n\nAD/B737/89 Main Deck Cargo Door \\- Existing Frame to Lower Sill Tie-Down\n\n  \n8/95\n\nApplicability: All B737-200, \\-300 equipped with a main deck cargo door installed in accordance with Pemco Supplemental Type Certificate SA969SO.\n\nRequirement: Do a close visual inspection for cracking of the fuselage frames below the lower jamb sill between stringers 20L and 21L at fuselage stations 380, 400, 420, 440, 460 and\n\n480.\n\nNote: FAA AD 95-06-05 and Pemco Alert Service Letter (ASL)737-53-0004 refer.\n\nCompliance: Initially inspect within 50 flights after 20 July 1995.\n\nRe-inspect at intervals not to exceed 450 flights until repaired in accordance with either of the schemes described in Pemco ASL 737-53-0004, Appendix I or II.\n\nBackground: Two operators have reported finding cracks in the upper ends of the Boeing installed frames which are fastened to the lower jamb structure. Cracking of these frames could result in loss of the cargo door.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains focused on B737-200 and -300 aeroplanes with the Pemco main-deck cargo door STC and on specified frame locations; the instrument sets inspection timing and repair pathways without expanding the class of affected aircraft or adding unrelated obligations (see Applicability, Requirement, Compliance, Note, Background)."},"complexity_factors":["Applicability limited to B737-200 and -300 aircraft with Pemco STC SA969SO — narrow scope reduces systemic complexity (Applicability).","Inspections target specific fuselage stations (380, 400, 420, 440, 460, 480) and the lower jamb sill between stringers 20L and 21L — requires technical competence to locate and assess (Requirement).","Short initial compliance window (within 50 flights) and recurring interval (≤450 flights) impose operational scheduling and monitoring burdens on operators (Compliance).","Repairs must follow one of two schemes in Pemco ASL Appendix I or II — reliance on an external manufacturer service document increases coordination and potential interpretation questions (Requirement, Note).","References to FAA AD 95-06-05 and Pemco Alert Service Letter introduce cross-jurisdictional/documentary dependencies that can complicate compliance verification (Note).","Safety-critical consequence (possible loss of cargo door) raises enforcement priority but does not itself add procedural complexity (Background)."],"plain_english_summary":"This directive requires operators of Boeing B737-200 and -300 aeroplanes fitted with a Pemco main-deck cargo door (Applicability) to do close visual inspections for cracking in fuselage frames below the lower jamb sill at specified stations, because cracking could cause loss of the cargo door (Background). An initial inspection is due within 50 flights of 20 July 1995 and re-inspections every ≤450 flights until repaired under Pemco ASL Appendix I or II (Requirement, Compliance). Operators pay for and arrange inspections/repairs and must follow the referenced Pemco ASL and FAA AD (Note)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural defect in a limited fleet subset. It has not expanded beyond its original purpose of mandating inspections for cargo door frame cracking."},"complexity_factors":["Single, specific technical requirement (visual inspection at defined locations)","Only 6 defined inspection points with clear spatial coordinates (fuselage stations and stringers)","Simple compliance timeline: initial inspection + recurring intervals until repair","No nested exceptions or conditional logic — applies to all listed aircraft uniformly","Short document (approximately 150 words of substantive content)","Single cross-reference to FAA AD and manufacturer service letter for technical details"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of Boeing 737-200/300s modified with the Pemco STC main-deck cargo conversion to inspect for cracks around the left-side fuselage frames by the main deck cargo door. A close visual check must be done within 50 flights (from 20 July 1995) and repeated every 450 flights until permanent repair. It addresses frame cracking that could lead to cargo-door failure, depressurization, or structural damage."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down","history":"/api/acts/ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down/history","analysis":"/api/acts/ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down/analysis","conflicts":"/api/acts/ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down/conflicts","importantCases":"/api/acts/ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down/important-cases","documents":"/api/acts/ad-b737-89-main-deck-cargo-door-existing-frame-to-lower-sill-tie-down/documents"}}