{"id":"F2006B04022","name":"AD/BEECH 55/77 - Engine Controls Support Structure","slug":"ad-beech-55-77-engine-controls-support-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43631,"registerId":"commonwealth-F2006B04022-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 55/77 - Engine Controls Support Structure","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 55, 58 and 95-55 (Baron) Series Aeroplanes\n\nAD/BEECH 55/77 Engine Controls Support Structure 2/93\n\nApplicability: Models Serial Numbers\n\n58 and 58A TH-1389 and TH-1396 through TH-1662\n\n58TC and 58TCA TK-147 and TK-151\n\n58P and 58PA TJ-436 and TJ-444 through TJ-497 Requirement: Modify the engine controls support structure in accordance with the instructions to\n\nBeech Kit No. 58-5016-1 S as referenced in Beech Service Bulletin 2439.\n\nNote: FAA AD 92-23-04 Amdt 39-8404.\n\nCompliance: Within 100 hours’ time in service after 4 February 1993.\n\nBackground: The FAA has received several reports of cracked angle attachment clips that support the engine controls inside the pedestal on the affected aircraft. The actions specified by this Directive are intended to prevent the loss of engine throttle control caused by failure of the attachment clips.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific mechanical defect in specific aircraft models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words)","Only 3 defined applicability categories (model groups with serial number ranges)","Single straightforward requirement with reference to external technical document (Beech Service Bulletin 2439)","No nested exceptions or conditional logic","Simple compliance deadline (100 hours time in service after fixed date)","Minimal cross-referencing (only to FAA AD 92-23-04 for background context)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Beechcraft Baron aircraft models.\n\n**What it does:**\n- Requires owners/operators of certain Beechcraft 58 and 95-55 series aeroplanes to modify the engine controls support structure\n- The modification must follow specific instructions using Beech Kit No. 58-5016-1 S, as detailed in Beech Service Bulletin 2439\n\n**Who it affects:**\n- Owners and operators of specific Beechcraft Baron models with particular serial numbers:\n  - Models 58 and 58A with serial numbers TH-1389 and TH-1396 through TH-1662\n  - Models 58TC and 58TCA with serial numbers TK-147 and TK-151\n  - Models 58P and 58PA with serial numbers TJ-436 and TJ-444 through TJ-497\n\n**Why it matters:**\n- The FAA (US aviation authority) received reports of cracked angle attachment clips that hold the engine controls inside the aircraft pedestal\n- If these clips fail, pilots could lose throttle control — a serious flight safety risk\n- This directive prevents potential accidents by mandating a structural fix before the components fail\n\n**Compliance deadline:**\n- Aircraft must be modified within 100 hours of flight time after 4 February 1993"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive retains a narrow, remedial scope: it targets a specific structural support issue on identified serial numbers and prescribes a particular manufacturer kit and procedure to prevent loss of throttle control (Applicability; Requirement; Background). There is no indication in the text that the scope has been broadened beyond that original remedial purpose."},"complexity_factors":["Narrow technical scope: applies only to specific Beechcraft models and serial numbers (Applicability).","Prescriptive remedy: requires installation of a specific manufacturer kit and references a service bulletin (Requirement).","Time-bound compliance: one clear deadline measured in hours’ time in service after a calendar date (Compliance).","Technical execution: requires skilled maintenance work and parts supply, creating operational downtime and administrative tracking.","Regulatory formality: is an airworthiness directive, so non‑compliance has regulatory consequences (document header and Schedule of Airworthiness Directives)."],"plain_english_summary":"Owners/operators of specified Beechcraft Baron 58-series aeroplanes must install Beech Kit No. 58-5016-1 S per Service Bulletin 2439 to modify the engine‑control support structure within 100 hours’ time‑in‑service after 4 Feb 1993. The work, required to prevent loss of throttle control from cracked attachment clips, imposes a one‑off parts, labour and downtime cost on operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-55-77-engine-controls-support-structure","history":"/api/acts/ad-beech-55-77-engine-controls-support-structure/history","analysis":"/api/acts/ad-beech-55-77-engine-controls-support-structure/analysis","conflicts":"/api/acts/ad-beech-55-77-engine-controls-support-structure/conflicts","importantCases":"/api/acts/ad-beech-55-77-engine-controls-support-structure/important-cases","documents":"/api/acts/ad-beech-55-77-engine-controls-support-structure/documents"}}