{"id":"F2006B08444","name":"AD/CESSNA 650/1 - Elevator Balance","slug":"ad-cessna-650-1-elevator-balance","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115940,"registerId":"commonwealth-F2006B08444-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 650/1 - Elevator Balance","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)  \nCessna 650 (Citation III) Series Aeroplanes\n\nAD/CESSNA 650/1 Elevator Balance 1/89 DM\n\nApplicability: All models S/No. 650-0094, 650-0096, 650-0100 to 650-0103, 650-0105 to 650-0107,\n\n650-0117, 650-0120, 650-0123, 650-0125 to 650-0129, 650-0131 to 650-0159,\n\n650-0161 and 650-0162.\n\nRequirement: Remove both elevators and re-balance in accordance with Cessna Alert Service Letter SLA 650-27-20.\n\nNote 1: This Directive restores “Enroute Operational Altitude Limit” to the original Approved Flight Manual limit. (Temporary Flight Manual Amdt A/C650/1 refers).\n\nNote2: FAA AD 88-23-04 refers.\n\nCompliance: Within 100 hours or 60 days time in service after 7 December 1988. Background: Some aircraft may have been manufactured with incorrectly balanced elevators.\n\nAnalysis has shown that the incorrect balance may result in a structural dynamic\n\ninstability above 45 000 ft.","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 manufacturing defect in specific aircraft. It has not expanded beyond its original purpose of correcting elevator balance issues in the identified Cessna 650 serial numbers."},"complexity_factors":["Single, specific technical requirement (remove and re-balance elevators)","Limited applicability (42 specific serial numbers listed explicitly)","Clear compliance deadline (100 hours or 60 days)","No nested exceptions or conditional logic","Only 2 brief notes providing cross-references","Total length: approximately 150 words","No defined terms section or interpretation provisions"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for specific Cessna 650 Citation III business jets.\n\n**What it does:**\n- Orders owners/operators of affected aircraft to **remove and re-balance both elevators** (the control surfaces on the tail that make the plane pitch up and down)\n- The work must follow Cessna's specific technical instructions (Alert Service Letter SLA 650-27-20)\n\n**Who it affects:**\n- Owners and operators of 42 specific Cessna 650 aircraft (listed by serial numbers)\n\n**Why it matters:**\n- Some planes were built with **incorrectly balanced elevators**\n- This creates a risk of **structural dynamic instability** (dangerous vibration/flutter) when flying above 45,000 feet\n- The fix restores the aircraft's original approved maximum operating altitude\n\n**Deadline:**\n- Must be completed within **100 flight hours or 60 days** after 7 December 1988\n\n**Key point:** This is a **retroactive safety fix** — it applies to planes already in service, not just new manufacturing."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The Directive not only mandates a technical corrective action (removal and re-balancing of both elevators) but explicitly restores the \"Enroute Operational Altitude Limit\" to the original Approved Flight Manual limit (Note 1). That restoration alters the operational scope of the affected aircraft until compliance and corrects a temporary flight manual amendment referenced in the AD (Note 1)."},"complexity_factors":["Narrow applicability limited to a specific list of serial numbers (Applicability).","Single prescriptive technical action: remove and re-balance both elevators per a named Cessna Alert Service Letter (Requirement).","Fixed, short compliance window (100 hours or 60 days after 7 December 1988) creates scheduling pressure (Compliance).","Dependence on an external technical document (Cessna SLA 650-27-20) for the detailed procedure (Requirement).","Safety-critical technical rationale tied to structural dynamic instability above a specific altitude (45,000 ft) (Background).","Reference to a parallel FAA AD, indicating cross-jurisdictional alignment but not extra procedural complexity (Note 2)."],"plain_english_summary":"The Civil Aviation Safety Authority requires specific serial-numbered Cessna 650 (Citation III) aeroplanes to have both elevators removed and re‑balanced per Cessna Alert Service Letter SLA 650‑27‑20 within 100 flight hours or 60 days after 7 December 1988. It targets listed owners/operators to fix incorrectly balanced elevators that could cause structural dynamic instability above 45,000 ft and restores the original enroute altitude limit."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-650-1-elevator-balance","history":"/api/acts/ad-cessna-650-1-elevator-balance/history","analysis":"/api/acts/ad-cessna-650-1-elevator-balance/analysis","conflicts":"/api/acts/ad-cessna-650-1-elevator-balance/conflicts","importantCases":"/api/acts/ad-cessna-650-1-elevator-balance/important-cases","documents":"/api/acts/ad-cessna-650-1-elevator-balance/documents"}}