{"id":"F2006B10895","name":"AD/JETSTREAM/27 Amdt 1 - Shear Angles at Wing Rib 36","slug":"ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56430,"registerId":"commonwealth-F2006B10895-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/27 Amdt 1 - Shear Angles at Wing Rib 36","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 BAe 3100 (Jetstream) Series Aeroplanes\n\nAD/JETSTREAM/27\n\nAmdt 1\n\n  \nShear Angles at Wing Rib 36 11/96\n\nApplicability: Jetstream Series 3100 series aircraft, that do not have modification JM5303 embodied.\n\nRequirement: Action in accordance with Jetstream Aircraft Alert Service Bulletin 57-A-JA 880144 Revision 2.\n\nCompliance: As specified in the requirement document.\n\nThe compliance of the initial issue of this directive remains unchanged for the inspection intervals. This amendment is effective from 10 October 1996.\n\nBackground: The cracking of shear angles was reported, and also detected by Jetstream fatigue testing.\n\nAmendment 1 is raised in response to the latest revision of the requirement document which is issued because the Accomplishment Instructions at the previous issue standard are potentially misleading.\n\nThe original issue of this airworthiness directive became effective on 6 October 1988.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original purpose: addressing shear angle cracking at Wing Rib 36 on Jetstream 3100 aircraft. The amendment only updates the incorporated technical instructions to fix ambiguity; it does not expand applicability, add new inspection types, or extend to other aircraft models or structural components."},"complexity_factors":["Very short document (under 200 words)","Only one defined applicability criterion (modification JM5303)","Single cross-reference to external technical document (Service Bulletin 57-A-JA 880144 Rev 2)","No nested conditions or exceptions — straightforward compliance requirement","Minimal legislative machinery — essentially a notice incorporating by reference a manufacturer bulletin"],"plain_english_summary":"This is a **safety notice for specific aircraft** — the British Aerospace Jetstream 3100 series.\n\n**What it does:**\n- Requires owners and operators of these planes to inspect and fix a structural problem at **Wing Rib 36** — specifically, metal brackets called \"shear angles\" that help transfer loads through the wing structure.\n- These brackets were found to crack, both in real aircraft and in fatigue testing.\n\n**Who must act:**\n- Anyone operating a Jetstream 3100 that **hasn't already been modified** with a specific factory fix (modification JM5303).\n\n**What they must do:**\n- Follow the instructions in **Jetstream Aircraft Alert Service Bulletin 57-A-JA 880144 Revision 2** — a technical document from the manufacturer detailing inspections and repairs.\n\n**Why this amendment exists:**\n- The original safety notice came out in 1988. This 1996 update (Amendment 1) doesn't change how often inspections must happen, but fixes the **instructions themselves** — the previous version was confusing and could lead mechanics to do the work incorrectly.\n\n**Bottom line:** If you fly or maintain one of these aircraft, check whether this applies to your plane, and make sure you're following the corrected technical instructions to prevent wing structural failures."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment does not expand or narrow the population of aircraft subject to the directive (still Jetstream Series 3100 aircraft without modification JM5303) and explicitly leaves the original inspection intervals unchanged. The only primary mechanical change is to require compliance with the updated Jetstream Aircraft Alert Service Bulletin 57-A-JA 880144 Revision 2 because earlier accomplishment instructions were potentially misleading; the AD therefore clarifies the required document rather than altering scope or inspection timing (Applicability; Requirement; Compliance; Amendment 1)."},"complexity_factors":["Reference to an external technical document (Jetstream Aircraft Alert Service Bulletin 57-A-JA 880144 Revision 2) for the substantive actions","Limited applicability conditional on embodiment of modification JM5303 (requires checking aircraft modification status)","Technical subject-matter (shear angles at wing rib 36) which requires specialist maintenance skills to implement","Potential prior ambiguity in earlier service instructions (Amendment 1 notes previous Accomplishment Instructions were potentially misleading)","Legal text is short and procedural; substantive operational detail is in the service bulletin rather than in the AD itself"],"plain_english_summary":"What this instrument does (mechanics)\n\n- Updates an existing airworthiness directive (AD) for British Aerospace BAe 3100 (Jetstream) Series 3100 aeroplanes by requiring operators to carry out the actions set out in Jetstream Aircraft Alert Service Bulletin 57-A-JA 880144 Revision 2. (Requirement)\n- Applies only to Jetstream Series 3100 aeroplanes that do not have modification JM5303 embodied; aircraft with JM5303 are excluded. (Applicability)\n- Leaves the previously stated inspection intervals unchanged — the timing of inspections required by the original AD remains as before. (Compliance)\n- Becomes effective on 10 October 1996. (Amendment 1)\n\nWho is affected\n\n- The direct financial and operational responsibility falls on operators/owners of Jetstream Series 3100 aeroplanes that have not incorporated modification JM5303. Those operators must follow the procedures and any inspections, repairs or modifications specified in the referenced service bulletin. (Applicability; Requirement; Compliance)\n\nWhy it was changed (stated purpose) and how that interacts with costs and incentives\n\n- The AD records that cracking of shear angles at wing rib 36 had been reported and observed during fatigue testing; the stated purpose of the required actions is to address that cracking. (Background)\n- The amendment updates the required service document to Revision 2 because the previous issue's Accomplishment Instructions were potentially misleading. The AD explicitly says the amendment responds to that revised requirement document. (Amendment 1; Requirement)\n\nPractical implications, trade-offs and implementation notes\n\n- Who pays: operators/owners of the affected aircraft bear the cost of complying with the service bulletin (inspection, repair or modification actions). (Applicability; Requirement)\n- What changes in behaviour: affected operators must follow the Revision 2 instructions in the named Jetstream Aircraft Alert Service Bulletin instead of the earlier issue. If an operator has already embodied JM5303, they are outside the AD and need not carry out these actions. (Applicability; Requirement)\n- Compliance burden: the AD delegates technical detail (inspection and remedial action content and timing) to the external service bulletin; the AD itself requires compliance “as specified in the requirement document”, so operational staff must obtain and follow that external document. (Requirement; Compliance)\n- Implementation risk and administrative discretion: the AD indicates the prior service instructions were potentially misleading and the latest revision corrects that; consistent compliance therefore depends on operators using the current (Revision 2) bulletin. The AD does not add alternate discretionary paths — it mandates following the named bulletin. (Amendment 1; Requirement)\n- Scope and timing: the AD does not change inspection intervals established by the original directive; it only updates the referenced service bulletin to clarify the accomplishment instructions. (Compliance; Amendment 1)\n\nSource citations (headings in the AD): Applicability; Requirement; Compliance; Amendment 1; Background."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36","history":"/api/acts/ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36/history","analysis":"/api/acts/ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36/analysis","conflicts":"/api/acts/ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36/conflicts","importantCases":"/api/acts/ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36/important-cases","documents":"/api/acts/ad-jetstream-27-amdt-1-shear-angles-at-wing-rib-36/documents"}}