{"id":"F2006B04267","name":"AD/BEECH 90/83 - Aft Fuselage Drainage","slug":"ad-beech-90-83-aft-fuselage-drainage","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44070,"registerId":"commonwealth-F2006B04267-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 90/83 - Aft Fuselage Drainage","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)  Beechcraft 90 and 65-90 (King Air) Series Aeroplanes\n\n \n\nAD/BEECH 90/83 Aft Fuselage Drainage 8/90\n\nApplicability: Models 65-90, 65-A90, B90, C90 and C90A with S/Nos LJ-1 through LJ-1222.\n\n \n\nModels E90, F90, H90 all S/Nos.\n\n \n\nRequirement: Action in accordance with Beechcraft Mandatory SB 2312.\n\n \n\nNote: FAA AD 90-08-17 refers.\n\n \n\nCompliance: Unless already accomplished, prior to exceeding 100 hours’ time in service after 9 August 1990, or at the next scheduled inspection for issue of Maintenance Release after 9 August 1990, whichever occurs later.\n\n \n\nBackground: Country of origin AD. A blocked drainage system may allow water to accumulate, freeze and restrict movement of the flight controls.\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 airworthiness directive focused specifically on aft fuselage drainage in particular Beechcraft models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, discrete safety requirement with no conditional branches or exceptions","Only 5 defined applicability criteria (aircraft models and serial number ranges)","Simple compliance timeline with two alternative triggers (hours flown or next inspection)","No cross-references to other legislation beyond a single FAA AD reference and one Beechcraft service bulletin","Background explanation provided in plain language","Total length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nRequires owners and operators of certain Beechcraft King Air aeroplanes (models 65-90, 65-A90, B90, C90, C90A, E90, F90, and H90) to inspect and fix the aft (rear) fuselage drainage system following a specific Beechcraft service bulletin.\n\n**Why it matters:**\nA blocked drainage system can trap water in the rear fuselage. If that water freezes, it can jam the flight controls — potentially causing loss of control of the aircraft. This directive prevents that dangerous scenario.\n\n**Who must comply:**\n- Owners/operators of affected Beechcraft 90-series King Air aircraft with specific serial numbers\n- Must be done before the aircraft reaches 100 flight hours after 9 August 1990, or at the next scheduled maintenance inspection after that date — whichever comes later\n\n**Key point:** This is a **retrospective safety fix** — it applies to aircraft already in service, not just new ones."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's stated scope matches its stated purpose: it targets specified Beechcraft 90-series aeroplanes and requires corrective action to address aft fuselage drainage to prevent water accumulation and freezing that could restrict flight controls. The instrument limits applicability by model and serial number and prescribes compliance by following Beechcraft Mandatory SB 2312 within a defined time window; there is no indication in the text supplied that the scope was expanded beyond this technical, model-specific safety correction. (See: \"Applicability...\", \"Requirement...\", \"Compliance...\", \"Background...\")"},"complexity_factors":["Clear, single technical requirement: follow Beechcraft Mandatory SB 2312 (low internal legal complexity). (See: \"Requirement: Action in accordance with Beechcraft Mandatory SB 2312.\")","Fixed, simple compliance window tied to flight hours or the next Maintenance Release (straightforward but operationally binding). (See: \"Compliance: ... prior to exceeding 100 hours’ time in service ... or at the next scheduled inspection for issue of Maintenance Release ...\")","Applicability limited to specific models and serial-number ranges (requires checking tail number records). (See: \"Applicability: Models 65-90... with S/Nos LJ-1 through LJ-1222. Models E90, F90, H90 all S/Nos.\")","Dependence on an external technical document (SB 2312) and a referenced FAA AD increases practical complexity for compliance because operators must obtain and apply another document. (See: \"Requirement: Action in accordance with Beechcraft Mandatory SB 2312.\" and \"Note: FAA AD 90-08-17 refers.\")","Technical subject-matter (airframe drainage and potential freezing affecting controls) requires qualified maintenance personnel, but the AD itself does not specify technical steps — that is delegated to the SB. (See: \"Background: ... blocked drainage system may allow water to accumulate, freeze and restrict movement of the flight controls.\")"],"plain_english_summary":"This AD requires owners/operators of specified Beechcraft 65-90/90 series aeroplanes (models 65-90, 65‑A90, B90, C90, C90A with S/N LJ‑1–LJ‑1222, and models E90, F90, H90) to perform the maintenance action in Beechcraft Mandatory SB 2312. \n\nWork must be done within 100 flight hours after 9 Aug 1990 or at the next Maintenance Release inspection. It was issued because blocked drainage can let water freeze and restrict flight‑control movement; compliance costs and scheduling are the owner/operator’s responsibility."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-90-83-aft-fuselage-drainage","history":"/api/acts/ad-beech-90-83-aft-fuselage-drainage/history","analysis":"/api/acts/ad-beech-90-83-aft-fuselage-drainage/analysis","conflicts":"/api/acts/ad-beech-90-83-aft-fuselage-drainage/conflicts","importantCases":"/api/acts/ad-beech-90-83-aft-fuselage-drainage/important-cases","documents":"/api/acts/ad-beech-90-83-aft-fuselage-drainage/documents"}}