{"id":"F2006B10929","name":"AD/JETSTREAM/59 - Main Wing Lower Skin and Lower Front Spar Structure","slug":"ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56473,"registerId":"commonwealth-F2006B10929-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/59 - Main Wing Lower Skin and Lower Front Spar Structure","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  British Aerospace BAe 3100 (Jetstream) Series Aeroplanes\n\n \n\n# AD/JETSTREAM/59  Main Wing Lower Skin and Lower Front Spar Structure\n\nApplicability: All Jetstream Series 3100 aircraft.\n\n# 9/93\n\n \n\nRequirement: Action in accordance with British Aerospace Jetstream Mandatory Service Bulletin 57-JA 921203.\n\n \n\nNote: UK CAA AD 014-05-93 refers.\n\n \n\nCompliance: As specified in the Requirement Document, with a completion date of 19 February 1994 for Accomplishment Instructions Parts 1 and 2 of the Requirement Document.\n\n \n\nBackground: Reports of exfoliation corrosion damage of the lower main skin at bolts which attach the skin to the front spar structure between Stations 36 and 40, LH and RH.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue safety directive focused on a specific structural defect in a specific aircraft type. It has not expanded beyond its original purpose of addressing exfoliation corrosion in the wing structure."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined applicability criterion (aircraft model)","Single requirement referencing an external document (the service bulletin)","No nested conditions or exceptions","Simple linear structure: applicability → requirement → compliance deadline → background","No cross-references to other legislation beyond a single note about a UK equivalent directive"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific maintenance action on certain aircraft.\n\n**What it does:**\n- **Targets:** All British Aerospace BAe 3100 (Jetstream) series aircraft\n- **Requires:** Operators must follow a specific service bulletin (British Aerospace Jetstream Mandatory Service Bulletin 57-JA 921203) to inspect and fix a structural problem\n- **The problem:** Corrosion damage (called \"exfoliation corrosion\") was found on the lower wing skin where it bolts to the front spar structure — basically, the metal was deteriorating at critical connection points on both left and right wings\n\n**Why it matters:**\n- **Safety critical:** Wing structure failures can be catastrophic\n- **Mandatory:** Aircraft cannot legally fly unless this is done by the deadline (19 February 1994 for the main inspection and repair steps)\n- **Time-sensitive:** The compliance date was fixed — no extensions without specific approval\n\n**Who needs to act:** Airlines, charter operators, or private owners flying Jetstream 3100 aircraft in Australia (or Australian-registered aircraft overseas)."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD as presented applies to all Jetstream Series 3100 aircraft and mandates work per British Aerospace Jetstream Mandatory Service Bulletin 57-JA 921203, with a specified completion date for certain instructions. The text does not indicate any expansion or narrowing of scope from an earlier or original intent; it sets a clear technical requirement and deadline without amendments or caveats in the provided text (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow technical scope: targets a specific structural area (lower main skin to lower front spar) between Stations 36 and 40 (Background).","External dependency: substantive work required is contained in an external manufacturer document (Mandatory Service Bulletin 57-JA 921203) rather than fully set out in the AD (Requirement).","Fixed compliance deadline for parts of the instructions (Completion date: 19 February 1994) creates scheduling urgency (Compliance).","Universal applicability within a single aircraft type (all Jetstream Series 3100) simplifies applicability but concentrates impact on that operator group (Applicability).","Cross-jurisdiction reference to UK CAA AD indicates aligned regulatory action but requires operators to track related foreign directives (Note)."],"plain_english_summary":"This AD requires all British Aerospace Jetstream Series 3100 operators to carry out the corrective inspections/repairs set out in Mandatory Service Bulletin 57-JA 921203 to address reported exfoliation corrosion at the lower main skin/forward spar (Stations 36–40).  \n\nWork specified in Parts 1 and 2 must have been completed by 19 February 1994; operators bear responsibility and cost for arranging compliance per the manufacturer’s instructions."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure","history":"/api/acts/ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure/history","analysis":"/api/acts/ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure/analysis","conflicts":"/api/acts/ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure/conflicts","importantCases":"/api/acts/ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure/important-cases","documents":"/api/acts/ad-jetstream-59-main-wing-lower-skin-and-lower-front-spar-structure/documents"}}