{"id":"F2006B04827","name":"AD/CA21/8 - Throttle Control Grub Screw","slug":"ad-ca21-8-throttle-control-grub-screw","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44628,"registerId":"commonwealth-F2006B04827-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CA21/8 - Throttle Control Grub Screw","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)  \nSkyfox Aviation (Calair/Hedaro) CA21 and CA22A Series Aeroplanes\n\nAD/CA21/8 Throttle Control Grub Screw 12/98\n\nApplicability: All Skyfox CA22A aircraft\n\n| Requirement: | 1.  | Inspect throttle control locking grub screw for security in accordance with Part A of Skyfox SB No.12 dated 18 March 1996. |\n| ------------ | --- | -------------------------------------------------------------------------------------------------------------------------- |\n|              | 2.  | Modify the throttle control in accordance with Part B of Skyfox SB No.12 dated 18 March 1996.                              |\n| Compliance:  | 1.  | Before next flight and thereafter every 25 flight hours until Requirement 2 is accomplished.                               |\n\n    2.a. Before next flight if inspection at Requirement 1 reveals a loose throttle control grub screw.\n\n    2.b. Within 100 flight hours of the effective date of this directive. This Airworthiness Directive becomes effective on 5 November 1998.\n\nNote: Previous compliance with all the requirements of Skyfox SB No.12 dated 18 March 1996 is considered to meet all the requirements of this Directive.\n\nBackground: In service experience and several in flight incidents has shown that the throttle control retaining grub screw can come loose if not engaged in a small recess in the cable slide and secured with Loctite. This Directive introduces a regular inspection to check the throttle control for security and a modification to ensure positive locking of the throttle control retaining grub screw. This Directive was issued against Skyfox CA25N aircraft in May 96 and should have been issued against CA22 aircraft at the same time.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating inspection and modification of the throttle control grub screw."},"complexity_factors":["Single, specific aircraft type (Skyfox CA22A)","Only 2 substantive requirements with clear sequential logic","Minimal defined terms (only standard aviation terminology like 'flight hours' and 'Service Bulletin')","Simple conditional compliance: immediate if unsafe, otherwise within 100 hours","No cross-references to other legislation beyond the parent Civil Aviation Regulations","Single background narrative explaining the safety rationale","Note provision for prior compliance (simple grandfathering clause)"],"plain_english_summary":"This Airworthiness Directive for Skyfox CA22A aircraft orders immediate and repeated inspections of the throttle cable grub screw (every 25 flight hours) and a mandatory permanent locking modification within 100 flight hours (or immediately if the screw is found loose), per Service Bulletin No. 12. \n\nIt affects all owners/operators/maintainers of Skyfox CA22A and addresses prior in‑flight incidents where the screw loosened and caused loss of engine power control."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"Originally issued against Skyfox CA25N aircraft in May 1996; this Directive applies the same inspection and modification requirements to CA22A aircraft and notes it should have been issued for CA22 earlier. The AD also accepts prior compliance with Skyfox SB No.12 as meeting its requirements."},"complexity_factors":["Narrow applicability: applies only to Skyfox CA22A aircraft (straightforward target population).","Clear, limited actions: one inspection requirement and one modification requirement (simple compliance actions).","Defined timelines: immediate inspection before next flight, recurring 25 flight‑hour checks until modification, and a 100 flight‑hour deadline for modification.","Reference to an external document (Skyfox SB No.12) for technical steps, creating dependency on that service bulletin for implementation.","Provision recognising prior compliance with Skyfox SB No.12 as satisfying the AD (allows alternative compliance pathway).","Operational implication: recurring inspection burden until modification increases maintenance scheduling needs for operators."],"plain_english_summary":"Requires operators of Skyfox CA22A aircraft to inspect the throttle-control retaining grub screw for security before the next flight and every 25 flight hours until a modification is fitted, and to apply the modification within 100 flight hours (or immediately if the screw is loose). The directive aims to prevent in‑flight incidents from a loose grub screw; it imposes inspection and modification costs on aircraft operators and tasks maintenance providers with carrying out the work."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-ca21-8-throttle-control-grub-screw","history":"/api/acts/ad-ca21-8-throttle-control-grub-screw/history","analysis":"/api/acts/ad-ca21-8-throttle-control-grub-screw/analysis","conflicts":"/api/acts/ad-ca21-8-throttle-control-grub-screw/conflicts","importantCases":"/api/acts/ad-ca21-8-throttle-control-grub-screw/important-cases","documents":"/api/acts/ad-ca21-8-throttle-control-grub-screw/documents"}}