{"id":"F2006B04240","name":"AD/BEECH 90/51 - Elevator Control System - Inspection and Modification","slug":"ad-beech-90-51-elevator-control-system-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44005,"registerId":"commonwealth-F2006B04240-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 90/51 - Elevator Control System - Inspection and Modification","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 90/51 Elevator Control System \\- Inspection\n\nand Modification\n\n  \n6/78\n\nApplicability: All models with s/Nos. LJ-114 to LJ-705 and LW-1 to LW-141 with Beechcraft H-14 autopilot installations except those which have incorporated Beech Mod. Kit. No. 90- 9067-15 or later approved revisions.\n\nRequirement: 1. To prevent chafing of the elevator cable and possible failure perform the following inspection:\n\n    (a) Open the aft fuselage belly access door and locate the autopilot elevator servo bellcrank at FS 319.00.\n\n    (b) Measure the bellcrank and if it measures 10 inches or less no further action is required.\n\n    (c) If the bellcrank measures 13.5 inches or larger, visually inspect the primary elevator control cable, the pulley bracket at FS 340.00, the autopilot servo cable, and autopilot bellcrank for cable rubbing and condition.\n\n    2. If rubbing of the elevator cable is noted, but no damage has occurred:\n\n    (a) Disconnect and remove the autopilot servo cable.\n\n    (b) Install a locally fabricated placard in plain view of the pilot indicating “Autopilot inoperative”.\n\n    3. If fraying of the elevator cable or other damage is noted:\n\n    (a) Replace the elevator cable and repair or replace any other damaged parts.\n\n    (b) Accomplish paragraph 2.\n\n    4. If not previously accomplished, modify the servo mount of any H-14 elevator autopilot servo having a 13.5 inch diameter or larger bellcrank in accordance with Beech Modification Kit No. 90-9067-15 or later approved revision and remove “Autopilot inoperative” placard.\n\nNote: Beechcraft Service Instruction No. 0988 refers.\n\nCompliance: 1. Before further flight.\n\n2. Before 1 September 1978.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive sets a targeted scope limited to aircraft listed in the Applicability and to H‑14 autopilot installations, excluding aircraft already modified with the specified Mod Kit. The instrument itself does not expand beyond those stated limits or change applicability within the text."},"complexity_factors":["Targeted applicability limited to specified serial-number ranges and H‑14 autopilot installations; exclusion where Mod Kit 90‑9067‑15 (or later) already installed (Applicability).","Conditional measurement thresholds drive diverging actions: bellcrank ≤10 in = no action; ≥13.5 in = detailed inspection and potential modification (Requirement 1(b)-(c)).","Tiered remedial steps: visual inspection, temporary removal of autopilot servo cable plus placard if rubbing, and mandatory cable replacement/repair when fraying is found (Requirement 1–3).","Temporary operational restriction (pilot placard “Autopilot inoperative”) until modification is completed, requiring local fabrication and cockpit marking (Requirement 2(a)-(b), 3(b)).","Mandatory modification uses a specific manufacturer modification kit (Beech Mod Kit No. 90‑9067‑15 or later), creating dependency on parts/approved revisions and maintenance capability (Requirement 4).","Dual compliance timing: immediate action ‘before further flight’ for inspections/repairs and a separate deadline (‘before 1 September 1978’) for placard/related compliance, imposing scheduling constraints.","Reference to additional manufacturer material (Beechcraft Service Instruction No. 0988) increases procedural detail that operators must consult.","Technical tasks (cable replacement, servo‑mount modification) require qualified maintenance resources and parts availability, imposing direct cost on aircraft owners/operators."],"plain_english_summary":"This airworthiness directive requires certain Beechcraft 90 and 65‑90 (King Air) aeroplanes with H‑14 autopilot installations (specific serial-number ranges) to have the elevator control/autopilot servo bellcrank inspected and, where necessary, cables repaired or replaced. If rubbing is found the autopilot servo cable must be removed and an “Autopilot inoperative” placard fitted until the servo mount is modified per Beech Mod Kit 90‑9067‑15. Compliance is immediate (before further flight) or by 1 September 1978."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect in a defined aircraft population. It has not expanded beyond its original purpose of mandating inspection and modification to prevent elevator cable failure."},"complexity_factors":["Short, single-purpose directive with clear sequential steps","Only 4 defined applicability criteria (model range, serial numbers, autopilot type, modification kit exemption)","Simple conditional logic (if bellcrank size X, then action Y)","No cross-references to other legislation or regulations beyond a single note referring to a service instruction","Plain language procedural requirements with minimal aviation jargon"],"plain_english_summary":"CASA orders owners/operators of certain Beechcraft King Air 90/65-90s with H-14 autopilots to inspect the tail autopilot bellcrank and elevator control cables for chafing that could lead to cable failure and loss of pitch control. Aircraft with Mod Kit 90-9067-15 are exempt.\n\nIf rubbing or damage is found, the autopilot cable must be disconnected (and a warning placard installed); damaged parts must be replaced before flight. Install the approved modification kit as a permanent fix; all actions by 1 Sept 1978."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-90-51-elevator-control-system-inspection-and-modification","history":"/api/acts/ad-beech-90-51-elevator-control-system-inspection-and-modification/history","analysis":"/api/acts/ad-beech-90-51-elevator-control-system-inspection-and-modification/analysis","conflicts":"/api/acts/ad-beech-90-51-elevator-control-system-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-beech-90-51-elevator-control-system-inspection-and-modification/important-cases","documents":"/api/acts/ad-beech-90-51-elevator-control-system-inspection-and-modification/documents"}}