{"id":"F2006B08424","name":"AD/CESSNA 550/19 - Freon Air Conditioner/Elevator Control Cable","slug":"ad-cessna-550-19-freon-air-conditioner-elevator-control-cable","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115898,"registerId":"commonwealth-F2006B08424-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 550/19 - Freon Air Conditioner/Elevator Control Cable","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 550 (Citation II) Series Aeroplanes\n\nAD/CESSNA 550/19 Freon Air Conditioner/Elevator\n\nControl Cable\n\n  \n7/90\n\nTX\n\nApplicability: Model 550, 551 and S550 series fitted with STC SA 2698SW freon air conditioning systems.\n\nRequirement: 1. Deactivate the air conditioning system by pulling the airconditioner circuit breakers on the main junction box and install tie wraps to preclude inadvertent re- setting.\n\n    2. Visually inspect the elevator control cables under and in the vicinity of the aft baggage compartment floor for evidence of damage caused by either arcing or chafe.\n\n    3. Replace mounting hardware on the inboard mounting rail and replace existing earth wire in accordance with Kieth Service Bulletin 108.\n\nNote: FAA Emergency AD 90-07-10 refers.\n\nCompliance: 1. Prior to further flight after 18 April 1990.\n\n    2. Within 10 hours time in service after 18 April 1990.\n\n    3. Prior to reactivating the airconditioning system.\n\nBackground: There has been a report of arcing from the freon airconditioning unit that has burned through an elevator control cable. A defect, if uncorrected, could lead to loss of control.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's scope is confined to aircraft fitted with the specified STC and targets the reported freon air‑conditioner arcing hazard to elevator control cables. It implements corrective actions (deactivate, inspect, replace hardware/earth wire) and sets short compliance deadlines; this aligns with the original hazard‑mitigation intent and does not expand beyond that narrowly defined applicability."},"complexity_factors":["Limited applicability: only Model 550/551/S550 with STC SA 2698SW freon AC.","Safety‑critical systems: involves elevator control cables and potential loss of control.","Multiple discrete actions required: deactivation, visual inspection, hardware and earth‑wire replacement.","Dependency on external document: replacement work specified by Kieth Service Bulletin 108.","Short compliance windows: immediate grounding or inspection within 10 hours increases operational impact.","Maintenance and parts cost burden lies with operators/maintenance organisations.","Reference to FAA Emergency AD increases cross‑jurisdictional coordination need."],"plain_english_summary":"This AD requires operators of Cessna 550/551/S550 aeroplanes fitted with STC SA 2698SW freon air‑conditioning to deactivate the freon unit and ensure inspection and replacement of affected elevator‑control hardware and earth wiring to prevent arcing that burned a control cable. It obliges aircraft operators and maintenance providers to stop flights until rectified, bearing the compliance and parts costs and deciding when the aircraft may resume service."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of preventing elevator cable damage from arcing air conditioning units."},"complexity_factors":["Very short document (under 300 words)","Only 3 defined applicability criteria (specific aircraft models and STC number)","Simple sequential compliance requirements (1, 2, 3) with clear deadlines","No cross-references to other legislation sections (only mentions FAA AD as background)","No conditional logic or exceptions — straightforward 'do this by this date' structure","Single background scenario driving all requirements"],"plain_english_summary":"This Airworthiness Directive mandates immediate action for certain Cessna 550 (Citation II) jets with the specified freon air‑conditioning unit: disable the A/C before the next flight (after 18 Apr 1990), have the elevator control cables under the aft baggage floor visually inspected within 10 flight hours for burning or wear, and complete required hardware/grounding replacements per the manufacturer’s service bulletin before re‑enabling the system. It responds to reported electrical arcing that burned a control cable, risking loss of pitch control and a possible crash."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-550-19-freon-air-conditioner-elevator-control-cable","history":"/api/acts/ad-cessna-550-19-freon-air-conditioner-elevator-control-cable/history","analysis":"/api/acts/ad-cessna-550-19-freon-air-conditioner-elevator-control-cable/analysis","conflicts":"/api/acts/ad-cessna-550-19-freon-air-conditioner-elevator-control-cable/conflicts","importantCases":"/api/acts/ad-cessna-550-19-freon-air-conditioner-elevator-control-cable/important-cases","documents":"/api/acts/ad-cessna-550-19-freon-air-conditioner-elevator-control-cable/documents"}}