{"id":"F2006B10549","name":"AD/HS 748/15 - Nose Landing Gear Jack Support Beam","slug":"ad-hs-748-15-nose-landing-gear-jack-support-beam","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116361,"registerId":"commonwealth-F2006B10549-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 748/15 - Nose Landing Gear Jack Support Beam","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)  \nBritish Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes\n\nAD/HS 748/15 Nose Landing Gear Jack Support Beam 5/95\n\nApplicability: All HS748 aircraft pre modification 1472.\n\nRequirement: Retire from service Main Landing Gear Jack Support Beam P/N 48 D 11498.\n\nNote: CAA(UK) AD 004-02-89 and British Aerospace Mandatory Service Bulletin 53/55 refer.\n\nCompliance: Retire before:\n\n    900 landings, if pre modification 684; or\n\n    b. 3000 landings, if post modification 684.\n\nNote: Embodiment of Modification 1472 (SB 53/28) cancels the requirement of this AD.\n\nBackground: Cracks have been reported in the subject nose landing gear jack support beam. Failure of this beam could result in an inability to extend or retract the nose landing gear.\n\nCAA(UK) compliance was 31 May 1989, this AD is issued to ensure aircraft recently imported into Australia meet this requirement.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements the same mechanical requirement described in the referenced UK AD and British Aerospace service bulletin: retire the specific nose landing gear jack support beam unless Modification 1472 is embodied. It does not broaden the set of affected parts or aircraft beyond the original safety measure; rather, it applies the existing requirement to HS 748 aircraft within Australia, including recently imported examples. (Background; Note)"},"complexity_factors":["Narrow applicability limited to HS 748 aircraft pre-modification 1472 (Applicability)","Simple prescriptive action: retire a single part by part number (Requirement)","Two different retirement thresholds based on embodiment of earlier modification 684 (Compliance)","Cancellation of the requirement if Modification 1472 is embodied, creating a binary compliance path (Note)","Need for operators to track landing counts accurately to determine compliance timing (Compliance)","Cross-references to external UK AD and manufacturer service bulletin for technical detail (Note)"],"plain_english_summary":"This Civil Aviation Safety Authority airworthiness directive requires retiring a specific nose-landing-gear jack support beam (P/N 48 D 11498) from service on Hawker Siddeley HS 748s still in the pre-modification 1472 configuration, because cracks could prevent nose-gear extension or retraction.  \n\nRetirement must follow landing-count thresholds (retire before 900 landings if pre‑mod 684, or before 3000 if post‑mod 684); embodying Modification 1472 cancels the retirement requirement for that aircraft."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a specific airworthiness directive with a narrow, targeted scope from inception. It addresses a known safety defect in a specific aircraft type and has not expanded beyond its original purpose of mandating replacement of the defective nose landing gear component."},"complexity_factors":["Very short document (under 200 words)","Only 2 conditional compliance paths based on modification status","Single defined technical term (P/N 48 D 11498 - part number)","No cross-references to other legislation sections","Simple binary applicability test (pre/post modification 684)","Clear cancellation condition (modification 1472 embodiment)"],"plain_english_summary":"This is a **safety directive** (called an \"Airworthiness Directive\") issued by Australia's Civil Aviation Safety Authority. It applies to a specific type of older British aircraft — the **HS 748 series** — that were brought into Australia.\n\n**What it does:**\n- **Orders the replacement** of a specific part on the nose landing gear (the \"jack support beam\") before it reaches a certain number of landings.\n- **Sets two deadlines:**\n  - If the aircraft hasn't had \"modification 684\" done: replace the part before **900 landings**\n  - If the aircraft has had \"modification 684\" done: replace the part before **3,000 landings**\n\n**Who it affects:**\n- Owners and operators of HS 748 aircraft in Australia that haven't had \"modification 1472\" installed.\n\n**Why it matters:**\n- Cracks have been found in this support beam. If the beam breaks, the nose landing gear might not extend or retract properly — meaning the plane couldn't land safely or might collapse on the ground. This directive prevents accidents by forcing replacement of the faulty part before it fails.\n\n**Key note:** If operators install \"modification 1472\" (a design fix), they don't need to follow this directive anymore."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-748-15-nose-landing-gear-jack-support-beam","history":"/api/acts/ad-hs-748-15-nose-landing-gear-jack-support-beam/history","analysis":"/api/acts/ad-hs-748-15-nose-landing-gear-jack-support-beam/analysis","conflicts":"/api/acts/ad-hs-748-15-nose-landing-gear-jack-support-beam/conflicts","importantCases":"/api/acts/ad-hs-748-15-nose-landing-gear-jack-support-beam/important-cases","documents":"/api/acts/ad-hs-748-15-nose-landing-gear-jack-support-beam/documents"}}