{"id":"F2006B02817","name":"AD/B737/115 - Horizontal Stabiliser","slug":"ad-b737-115-horizontal-stabiliser","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42159,"registerId":"commonwealth-F2006B02817-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/115 - Horizontal Stabiliser","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/B737/115 Horizontal Stabiliser 3/98 TX\n\nApplicability: Model 737-300, \\-400, and \\-500 series aircraft having line positions 2765 through\n\n2977.\n\nRequirement: Perform the following inspections of the left and right hand sides of the horizontal stabiliser:\n\n    Perform a general visual inspection to determine if any fasteners are missing on the top and bottom of the leading edge skin where it is attached to the front spar.\n\n    2. Perform a detailed visual inspection to detect loose or missing fasteners of the attachment of the elevator hinge plates to the left and right hand sides of the horizontal stabiliser rear spar fittings. Ensure torque sealant has not been broken on the fasteners.\n\n    If no discrepancies are found, no further inspections are required by this Directive.\n\n    b. If any fastener is loose or missing, or if the torque sealant has been broken on any fastener, install a new or serviceable fastener.\n\nNote: FAA Telegraphic AD T98-02-51 refers.\n\nCompliance: Within 5 flight cycles or within 24 clock hours after receipt of this Directive, whichever occurs later.\n\nThis airworthiness directive becomes effective on 9 January 1998.\n\nBackground: Preliminary reports from a Boeing Model 737 on-site accident investigation indicate that the horizontal stabiliser may have separated from the aircraft prior to impact with terrain. On-site investigation revealed that approximately 26 fasteners were missing from certain leading edge structure on the right hand horizontal stabiliser.\n\nAdditionally, early reports indicated that at least one fastener may have been missing from an elevator attachment fitting in an outboard section of the right hand horizontal stabiliser.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope is limited to specified 737‑300/‑400/‑500 line positions and to immediate inspections and repairs of horizontal stabiliser fasteners. The text shows the measure addresses the specific missing‑fastener reports and sets a short compliance window; it does not indicate an expansion or narrowing beyond that stated objective."},"complexity_factors":["Narrow applicability by serial/line positions (Applicability) — reduces universe but requires fleet filtering.","Two inspection levels: general visual of leading edge and detailed visual of elevator‑hinge fasteners (Requirement ¶1–2) — different skill/access requirements.","Short compliance deadline (within 5 flight cycles or 24 hours) (Compliance) — creates scheduling, access and parts‑availability pressure.","Simple remedial action (install new/serviceable fastener) but may require parts/close access to stabiliser structure (Requirement ¶2b).","Need to check torque sealant integrity (Requirement ¶2) — adds a qualitative check beyond presence/absence.","Reference to FAA telex AD (Note) — cross‑jurisdictional coordination for technical detail and parts/serviceability criteria.","Background safety incident (Background) explains urgency but implies potential for broader inspections if more defects found."],"plain_english_summary":"This directive requires operators of Boeing 737‑300/‑400/‑500 aircraft (line positions 2765–2977) to inspect both sides of the horizontal stabiliser for missing or loose leading‑edge and elevator‑hinge fasteners, and to install serviceable fasteners where defects are found. It was issued after reports the stabiliser may have separated and missing fasteners were found; compliance is required within five flight cycles or 24 hours, so operators carry the inspection and repair costs and must prioritise immediate access, parts and labour."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive issued in response to a specific accident investigation. It addresses exactly one safety issue (horizontal stabiliser fastener integrity) on a defined subset of aircraft. There is no indication of scope creep; the directive is precisely calibrated to the safety risk identified in the accident report."},"complexity_factors":["Single, specific mechanical issue addressed (missing/loose fasteners)","Only two inspection types required with clear pass/fail criteria","Narrow applicability (specific Boeing 737 models, specific production line numbers)","Simple conditional logic: if discrepancies found → replace fasteners; if not → done","No defined terms section, no cross-references to other legislation beyond a note about the corresponding FAA directive","Clear, single compliance deadline (5 flight cycles or 24 hours)","Background section provides straightforward factual context without legal complexity"],"plain_english_summary":"Australia's Civil Aviation Safety Authority has issued an urgent Airworthiness Directive requiring immediate inspection of the horizontal stabiliser on certain Boeing 737-300/-400/-500 airframes (line positions ~2765–2977). Operators and maintenance crews must check for missing or loose bolts and replace any unserviceable hardware within 5 flights or 24 hours.\n\nThis emergency order follows a crash investigation that found 26 missing stabiliser bolts and aims to prevent catastrophic stabiliser separation."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-115-horizontal-stabiliser","history":"/api/acts/ad-b737-115-horizontal-stabiliser/history","analysis":"/api/acts/ad-b737-115-horizontal-stabiliser/analysis","conflicts":"/api/acts/ad-b737-115-horizontal-stabiliser/conflicts","importantCases":"/api/acts/ad-b737-115-horizontal-stabiliser/important-cases","documents":"/api/acts/ad-b737-115-horizontal-stabiliser/documents"}}