{"id":"F2006B04261","name":"AD/BEECH 90/76 Amdt 2 - Elevator Trim Tab System","slug":"ad-beech-90-76-amdt-2-elevator-trim-tab-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44059,"registerId":"commonwealth-F2006B04261-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 90/76 Amdt 2 - Elevator Trim Tab System","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)  \nBeechcraft 90 and 65-90 (King Air) Series Aeroplanes\n\nAD/BEECH 90/76\n\nAmdt 2\n\n  \nElevator Trim Tab System 13/88\n\nApplicability: All models listed in the Requirement Document.\n\nRequirement: a. Action in accordance with Beech SB 2028 R IV Parts I, II, III, IV, V, VI, VII, VIII as applicable.\n\nb. Verify the operation of the elevator trim system in accordance with the Interim Addendum to the FAA approved Flight Manual and Pilots Operating Handbook, (attached to the Requirement Document).\n\nc. Action in accordance with Beech SB 2028 R IV Parts IV, V, VI as applicable.\n\nNote: FAA AD’s 86-20-03 and 87-04-24 refer.\n\nCompliance: a. Part I \\- Within 25 hours’ time in service after 20 November 1986.\n\nPart II \\- At the next scheduled inspection for Maintenance Release after 20 November 1986.\n\nPart III, IV, V, VI \\- as applicable prior to 15 May 1987.\n\nPart VIII \\- At the next scheduled inspection for Maintenance Release after 30 January 1989.\n\nb. Prior to each flight after compliance with Part I or Part II until modified.\n\nNote: This inspection may be accomplished by the pilot in command, in which case the precise A.D. reference shall be entered in a certification made on the Maintenance Release coincident with the Daily Inspection.\n\nc. Aircraft modified to Part III of SB 2028 R II; prior to 24 March 1987.\n\nBackground: The manufacturer reports cases of disengagement of the elevator trim cable from the cable drum. This has inhibited movement of the trim tab and increased elevator control forces excessively, thereby resulting in an unsafe condition. Amendment 1 references R III of the Requirement Document. R III requires additional modification to prevent water in the cable drum from freezing and immobilizing the trim system. The compliance period for modification is extended. Those aircraft already modified to Part III require additional work due to an unsafe condition. Amendment 2 references Rev IV of the Requirement Document which adds Part VIII, requiring additional work on trim actuator.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The directive has expanded significantly from its original scope. Initially addressing cable disengagement from the drum, Amendment 1 added freeze-protection modifications, and Amendment 2 added Part VIII requiring additional work on the trim actuator. The compliance structure also grew more complex — originally focused on Parts I–VI, it now spans eight parts with staggered deadlines extending from 1986 to 1989. What began as a single unsafe condition (cable slippage) now addresses three distinct failure modes (disengagement, freezing, actuator defects)."},"complexity_factors":["Multiple amendment layers (Amendment 2 references Revision IV of underlying Service Bulletin, which itself supersedes earlier revisions R II and R III)","Eight distinct parts (I–VIII) with different compliance deadlines and applicability","Conditional applicability ('as applicable') requiring cross-referencing with aircraft modification status","Dual compliance pathways — some deadlines based on flight hours, others on calendar dates or scheduled maintenance events","Pilot-permissible inspection creates documentation burden (specific AD reference required on Maintenance Release)","External document dependency — full requirements contained in referenced Beech Service Bulletin 2028 R IV and FAA Flight Manual Addendum, not reproduced in the AD itself","Nested background explaining evolution through Amendments 0, 1, and 2 with changing unsafe conditions"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection and modification of the elevator trim tab system on Beechcraft King Air 90/65‑90 series aircraft to address trim cable slippage, water freezing in the cable drum, and trim actuator problems. It applies to aircraft owners/operators, licensed maintenance engineers, and pilots (for pre‑flight checks).\n\nThe issue can jam the trim, forcing excessive control forces and creating a serious safety risk. Compliance is mandatory — an aircraft cannot legally fly until the required inspections/modifications are completed and recorded."},"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"},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"The AD's scope broadened beyond initial inspections to require progressively more modifications: Amendment 1 added work to prevent water ingress/freezing in the cable drum and extended compliance timing; Amendment 2 (Rev IV) adds Part VIII requiring additional trim actuator work and further modification of aircraft previously altered under Part III."},"complexity_factors":["Cross‑references to multiple external documents: Beech SB 2028 Rev IV and an Interim FAA Flight Manual/Pilot's Operating Handbook addendum (Requirement and Requirement Document).","Multiple Parts (I–VIII) with different applicability and staggered compliance deadlines (e.g. Part I: within 25 hours; other parts: next scheduled inspection; specified dates prior to 15 May 1987 and 24 March 1987).","Allows pilot to perform recurring pre‑flight inspection but requires a precise AD reference entry on the Maintenance Release, creating mixed‑competency compliance paths and recordkeeping obligations.","Some aircraft already modified to earlier revisions require additional corrective work (aircraft modified to Part III require additional work), increasing tracking burden for operators.","Amendment history adds new mandated work (Part VIII: trim actuator) and extends or adjusts compliance windows, increasing implementation and planning complexity for maintenance organisations.","Safety‑critical system (elevator trim) heightens enforcement and operational risk if compliance is incomplete."],"plain_english_summary":"This AD requires operators of Beechcraft 90 and 65‑90 (King Air) aircraft to inspect and modify the elevator trim tab system using Beech Service Bulletin 2028 Rev IV and an FAA interim flight‑manual check. The measure addresses trim‑cable disengagement and frozen cable drums that can immobilise the trim and raise elevator control forces. The AD sets staggered deadlines for inspections, modifications and recurring pre‑flight checks, so operators meet specified work and record‑keeping obligations and bear the cost of inspections and fittings."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-90-76-amdt-2-elevator-trim-tab-system","history":"/api/acts/ad-beech-90-76-amdt-2-elevator-trim-tab-system/history","analysis":"/api/acts/ad-beech-90-76-amdt-2-elevator-trim-tab-system/analysis","conflicts":"/api/acts/ad-beech-90-76-amdt-2-elevator-trim-tab-system/conflicts","importantCases":"/api/acts/ad-beech-90-76-amdt-2-elevator-trim-tab-system/important-cases","documents":"/api/acts/ad-beech-90-76-amdt-2-elevator-trim-tab-system/documents"}}