{"id":"F2006B04818","name":"AD/CA21/10 Amdt 1 - Ailerons","slug":"ad-ca21-10-amdt-1-ailerons","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44616,"registerId":"commonwealth-F2006B04818-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CA21/10 Amdt 1 - Ailerons","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)  \n![](image.002.png)  \nSkyfox Aviation (Calair/Hedaro) CA21 and CA22A Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/CA21/10 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nAD/CA21/10\n\nAmdt 1\n\n  \nAilerons 10/2000 TX\n\nApplicability: All CA21, CA22 and CA22A series aircraft.\n\nRequirement: 1. Following instructions approved by a CAR 35 Authorised Person, inspect both the left and right ailerons for:\n\n    Balance;\n\n    b. Rigging;\n\n    c. Corrosion, internal and external; and\n\n    d. Cracks in the joint between the aileron’s torque tube and its spar.\n\nNote 1: The reason the Authority is not able to rely on the above inspections being done as part of normal maintenance is that none of the above inspections are included in the maintenance manual. That is the reason for this AD.\n\n    2. Following instructions approved by a CAR 35 Authorised Person, improve the sealing and drainage of both left and right ailerons.\n\n    3. Following instructions approved by a CAR 35 Authorised Person, inspect both the left and right ailerons for conformity with the type design of the joint between the aileron’s torque tube and its spar.\n\nNote 2: In other words, check that the joint was built to drawing.\n\nCompliance: For Requirement 1:\n\n    Inspect before further flight after 24 August 2000.\n    Reinspect at the times specified in the instructions approved by the CAR 35 Authorised Person.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nNote 3: Inspection for corrosion and cracks is not required before further flight if the ailerons have been inspected since 7 July 2000 by a method approved by either the Authority or a CAR 35 Authorised Person. However, ailerons must be reinspected later at the times specified in instructions approved for Amendment 1 to this Airworthiness Directive by a CAR 35 Authorised Person.\n\nNote 4: CAR 35 Authorised Persons may include in their instructions an option to modify the ailerons to avoid the need for further inspections for corrosion and cracks (Requirements 1c and 1d).\n\nFor Requirements 2 and 3: Before further flight after 7 September 2000.\n\nNote 5: The Requirement 3 inspection is not necessary if the joint has been modified to a design approved under CAR 35. See Note 4.\n\nThis amendment becomes effective on 24 August 2000.\n\nBackground: The Civil Aviation Safety Authority received a report of the in-flight separation of the right hand aileron from a Skyfox CA25N aircraft. Investigation revealed that a failure occurred where the aileron’s torque tube attaches to its spar.\n\nFurther investigation has not been able to conclusively determine the cause of the failure. However it has revealed several potentially unsafe conditions that were not covered by the original issue of this AD. Therefore Amendment 1 expands the set of potentially unsafe conditions that must be checked before further flight. Also, in the absence of an active Type Certificate holder, Amendment 1 allows technically competent industry representatives to develop and approve their own safety solutions.\n\nThe original issue of this Airworthiness Directive became effective on 7 July 2000.\n\n![](image.003.png)  \n\nNeville James Probert\n\nDelegate of the Civil Aviation Safety Authority 24 August 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 24 August 2000.","sortOrder":0}],"analysis":{"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original AD (effective 7 July 2000) was issued in response to a specific in-flight aileron separation incident. Amendment 1 significantly expands the scope beyond the original failure mode to cover: (1) additional potential unsafe conditions not originally identified (balance, rigging, corrosion, drainage issues); (2) conformity with type design verification; and (3) introduces a delegated approval mechanism via CAR 35 Authorised Persons due to the absence of an active Type Certificate holder. The amendment transforms a targeted reactive directive into a broader preventive safety regime."},"complexity_factors":["Single regulatory instrument type (Airworthiness Directive) with standardised structure","Only 3 substantive requirements, though with sub-elements (1a-d)","5 explanatory notes providing context and exceptions","Cross-references to CAR 1998 (Civil Aviation Regulations) and CAR 35 (design approval framework)","Conditional compliance provisions (e.g., Note 3 exemption for recent inspections, Note 4 modification options, Note 5 exemption for modified joints)","Moderate technical aviation terminology requiring domain knowledge (aileron, torque tube, spar, type design, CAR 35 Authorised Person)","Temporal complexity with multiple effective dates and compliance deadlines (24 August 2000, 7 September 2000, 7 July 2000 reference date)"],"plain_english_summary":"This CASA safety order, replacing a prior 2000 order, requires urgent inspections and corrective work on the ailerons of Skyfox CA21/CA22/CA22A aeroplanes after an in-flight aileron separation. Owners/operators must check balance, rigging, corrosion, torque-tube-to-spar joints, improve sealing/drainage, and confirm conformity with type design.\n\nWith the manufacturer defunct, CAR 35 Authorised Persons may develop and approve methods. Initial inspections due before flight after 24 Aug 2000; further work before flight after 7 Sep 2000."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the original AD’s scope: it adds additional inspection items (balance, rigging, internal/external corrosion and specific torque‑tube/spar joint crack checks), requires improvement of sealing/drainage, and adds a conformity check against type design. It also broadens approval authority by allowing CAR 35 Authorised Persons (including technically competent industry representatives where no Type Certificate holder is active) to develop and approve corrective instructions or modifications (Background; Requirements; Notes 1–5)."},"complexity_factors":["Multiple distinct inspection requirements (balance, rigging, corrosion internal/external, cracks) increasing inspection scope and technical diversity.","Different compliance timings and exceptions (inspect before further flight after 24 Aug 2000; certain inspections excepted if done since 7 Jul 2000; other requirements before 7 Sep 2000).","Reliance on instructions approved by a CAR 35 Authorised Person rather than fixed maintenance manual procedures (discretion and heterogeneity of approved methods).","Option to modify ailerons to remove need for ongoing inspections if approved (introduces alternative compliance paths and approval decisions).","Conformity check against type design/drawings for the torque-tube/spar joint (requires access to design documentation and interpretation).","Background uncertainty about root cause (investigation inconclusive) leading to broader, precautionary requirements rather than a single targeted fix.","Interaction with absence of an active Type Certificate holder — shifts approval authority to industry representatives, changing governance and potential for inconsistent solutions.","Notes and cross-references (Notes 1–5) create conditional rules that require careful reading to determine when inspections are immediately required versus deferred."],"plain_english_summary":"This amendment requires owners/operators of Skyfox CA21/CA22/CA22A aeroplanes to have a CAR 35 Authorised Person inspect both ailerons for balance, rigging, internal/external corrosion and cracks at the torque-tube/spar joint, and to improve aileron sealing and drainage. Inspections and any approved modifications must be carried out before further flight according to the AD’s dates and reinspection schedule. The AD says these measures respond to an in‑flight aileron separation and allows CAR 35 persons to develop and approve fixes where no Type Certificate holder is active."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ca21-10-amdt-1-ailerons","history":"/api/acts/ad-ca21-10-amdt-1-ailerons/history","analysis":"/api/acts/ad-ca21-10-amdt-1-ailerons/analysis","conflicts":"/api/acts/ad-ca21-10-amdt-1-ailerons/conflicts","importantCases":"/api/acts/ad-ca21-10-amdt-1-ailerons/important-cases","documents":"/api/acts/ad-ca21-10-amdt-1-ailerons/documents"}}