{"id":"F2006B02569","name":"AD/AUS/18 - Fabric Covering","slug":"ad-aus-18-fabric-covering","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41825,"registerId":"commonwealth-F2006B02569-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AUS/18 - Fabric Covering","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)  \nAuster/Beagle A.61 Series Aeroplanes\n\nAD/AUS/18 Fabric Covering 3/64\n\nApplicability: Mk. III with wings not covered to Dwg. EEH-48.\n\nMk. IV and V with wings not covered to Dwg. EGH-37. J1 with wings not covered to Dwg. EJH-72.\n\nJ1B, J1N with wings not covered to Dwg. EJH-72. J2 and J4 with wings not covered to Dwg. EJH-52. J5 with wings not covered to Dwg. EJH-72.\n\nOther J5 series with wings not covered to Dwg. EJH-437.\n\nRequirement: 1. Modify the wing rib stringing by introducing additional stringing in the leading edge area - Beagle Drawing No. CSK 3483 refers.\n\n2. When it becomes necessary to recover the wing it shall be recovered to the appropriate scheme called up in paragraph 1 or a scheme approved by the Secretary.\n\nNote: Beagle Service Bulletin (Auster Series) No. 53 contains all relevant information.\n\nCompliance: Forthwith.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument applies to a defined set of Auster/Beagle A.61 variants whose wings are not built to specified drawings, and it prescribes a particular structural modification and covering scheme or a Secretary-approved alternative (Applicability; Requirement 1; Requirement 2). The text does not indicate an expansion beyond those listed aircraft or beyond the stated modification and recovery requirements, so there is no evident change of scope from what the instrument itself sets out."},"complexity_factors":["Targeted applicability to specific marks/subtypes tied to particular manufacturer drawing numbers (Applicability).","Single, narrowly framed technical requirement (addition of leading-edge stringing) with a single referenced drawing (Requirement 1).","Relies on an external manufacturer service bulletin for detailed instructions (Note).","Allows an alternate scheme but only with Secretary approval, introducing limited regulatory discretion (Requirement 2).","Immediate compliance phrasing (\"Forthwith\") raises scheduling urgency though the substantive change is narrow (Compliance).","Interpretative point over timing: the phrase \"when it becomes necessary to recover the wing\" links action to maintenance events rather than a uniform timetable (Requirement 2)."],"plain_english_summary":"What this instrument does (mechanical change)\n\n- It requires certain Auster/Beagle A.61 series aeroplanes with wings that are not built to specific manufacturer drawings to have additional fabric/wing structure added to the wing leading edge (Requirement 1). The specific change is \"additional stringing in the leading edge area\" and is referenced to Beagle Drawing No. CSK 3483 (Requirement 1).\n\n- It also requires that when a wing is re-covered (i.e. recovering the fabric covering), the covering must follow the scheme called up in Requirement 1 (the CSK 3483 scheme) or a different scheme that has been approved by the Secretary (Requirement 2).\n\nWhich aircraft are affected\n\n- The applicability list names specific marks and subtypes of the Auster/Beagle A.61 family whose wings are not built to particular drawings. The affected types are: Mk. III (wings not to Dwg. EEH-48); Mk. IV and V (not to Dwg. EGH-37); J1 (not to Dwg. EJH-72); J1B and J1N (not to Dwg. EJH-72); J2 and J4 (not to Dwg. EJH-52); J5 (not to Dwg. EJH-72); and other J5 series with wings not to Dwg. EJH-437 (Applicability).\n\nWho pays and who decides\n\n- Owners/operators of the listed aeroplanes must carry out the modification and any required re-covering. They will therefore incur the direct cost and bear the operational burden of doing the work (Requirement 1; Requirement 2; Compliance).\n\n- The Secretary (an administrative regulator named in the instrument) has the discretion to approve an alternative recovery scheme if an alternative is proposed (Requirement 2). The instrument also points to Beagle Service Bulletin (Auster Series) No. 53 for the detailed technical information (Note).\n\nTiming and compliance burden\n\n- Compliance is required immediately: the instrument states \"Forthwith\" (Compliance). That creates an immediate obligation to modify affected aircraft and to adopt the specified recovery scheme at the next re-covering.\n\nInformation and implementation\n\n- The AD cites Beagle Drawing No. CSK 3483 as the specified modification drawing (Requirement 1) and directs readers to Beagle Service Bulletin No. 53 for the relevant detailed information (Note). That means operators must obtain and follow those manufacturer materials or seek Secretary approval for an alternate scheme (Requirement 2; Note).\n\nStated purpose and practical trade-offs (source-grounded)\n\n- The instrument’s title and requirements identify fabric covering/wing construction as the target of the directive (title: \"Fabric Covering\"; Requirement 1 and 2). Taken at face value, the AD changes the wing rib stringing and controls how wings are re-covered.\n\n- Costs and incentives: operators pay for the modification and for any re-covering carried out under the mandated scheme (Requirement 1; Requirement 2). The Secretary’s approval power creates a route for alternatives but also a regulatory discretion that operators must engage with if they seek a different method (Requirement 2).\n\n- Compliance burden and implementation risk: the requirement to follow a particular drawing and the referral to a specific service bulletin concentrates technical compliance on those documents (Requirement 1; Note). The word \"Forthwith\" makes the timing immediate, which can raise scheduling and cost pressures for operators (Compliance). The provision \"when it becomes necessary to recover the wing\" creates a timing link to maintenance cycles for re-covering (Requirement 2), which affects when costs are incurred.\n\n- Behavioural effect: operators of affected aeroplanes must either modify existing wing rib stringing immediately and thereafter ensure re-covering follows the required scheme, or obtain Secretary approval for an alternative scheme (Requirement 1; Requirement 2). Beagle Service Bulletin No. 53 is the technical source for carrying out the work (Note).\n\nSource citations: Applicability; Requirement 1 and 2; Note; Compliance."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural weakness in a narrow category of vintage aircraft. It has not expanded beyond its original purpose of mandating wing reinforcement for fabric-covered Auster/Beagle aircraft."},"complexity_factors":["Very short document (under 200 words)","Only 3 defined elements: the drawing references (CSK 3483, plus the E-series drawings in the applicability section)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional logic: applies IF wing not covered to specific drawing, THEN modify","Single compliance deadline ('Forthwith' = immediate)","No nested exceptions or subordinate clauses"],"plain_english_summary":"This is a **safety directive** (called an \"Airworthiness Directive\") issued by Australia's Civil Aviation Safety Authority. It applies to specific models of **Auster/Beagle A.61 series aeroplanes**—small, older aircraft with fabric-covered wings.\n\n**What it does:**\n- **Targets specific aircraft** with wings that weren't built to certain original design drawings (the \"Dwg.\" references in the Applicability section).\n- **Requires two safety modifications:**\n  1. **Immediate modification:** Add extra support \"stringing\" (reinforcement strips) to the leading edge of the wings, following Beagle Drawing CSK 3483.\n  2. **Future requirement:** Whenever the wing fabric needs replacing, it must be recovered using either the new reinforced scheme or an alternative approved by the Secretary (the government official responsible for aviation safety at the time).\n\n**Who it affects:**\n- Owners and operators of specific Auster/Beagle aircraft models (Mk. III, IV, V, J1, J1B, J1N, J2, J4, and various J5 series).\n- Only applies if the wings weren't originally built to the stronger design drawings listed.\n\n**Why it matters:**\nFabric-covered wings on older aircraft can weaken over time. This directive prevents potential structural failures by strengthening the wing's leading edge—critical for maintaining lift and preventing accidents. The \"Forthwith\" compliance means **do it immediately**, not when convenient.\n\n**Historical note:** This directive dates from March 1964 (the \"3/64\" in the reference), showing how aviation safety authorities have long issued mandatory fixes for discovered design weaknesses."}},"importantCases":[],"_links":{"self":"/api/acts/ad-aus-18-fabric-covering","history":"/api/acts/ad-aus-18-fabric-covering/history","analysis":"/api/acts/ad-aus-18-fabric-covering/analysis","conflicts":"/api/acts/ad-aus-18-fabric-covering/conflicts","importantCases":"/api/acts/ad-aus-18-fabric-covering/important-cases","documents":"/api/acts/ad-aus-18-fabric-covering/documents"}}