{"id":"F2022L00609","name":"AD/YA-1/1 Main Landing Gear Top Attachment Bolts - Replacement","slug":"ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":102417,"registerId":"commonwealth-F2022L00609-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Yeoman Aircraft YA-1 Series Aeroplanes","sectionType":"part","heading":"Yeoman Aircraft YA-1 Series Aeroplanes","content":"# Yeoman Aircraft YA-1 Series Aeroplanes\n\n| AD/YA-1/1 | Main Landing Gear TopAttachment Bolts - Replacement | 8/2022 |\n| --------- | --------------------------------------------------- | ------ |\n\n| Applicability: | All models of Yeoman Aircraft YA-1 series aircraft.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Replace the original main landing gear top attachment bolts.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| Compliance:    | 1. Aircraft not modified in accordance with Yeoman Aircraft Service Bulletin (SB) YA1-SB002 dated 25 February 1963, as in force on the commencement date of this AD:Within 90 days after the commencement date of this AD, unless previously accomplished, and then at intervals not exceeding 100 hours’ time in service.2. Aircraft modified in accordance with Yeoman Aircraft SB YA1-SB002, dated 25 February 1963, as in force on the commencement date of this AD:Within 90 days after the commencement date of this AD, unless previously accomplished, and then at intervals not exceeding 750 hours’ time in service. |\n|                | This AD commences on 29 April 2022.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| Background:    | This AD is being re-made under Part 39 of the Civil Aviation Safety Regulations 1998 (CASR) because an example of the aircraft type, for which Australia is the State of Design, has returned to the Australian aircraft register and the AD had previously lapsed due to the Legislation Act 2003.                                                                                                                                                                                                                                                                                                                            |\n\n![Text\nDescription automatically generated](image.001.jpeg)\n\nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n14 April 2022","sortOrder":0},{"sectionNumber":"AD/YA-1/1","sectionType":"part","heading":"AD/YA-1/1","content":"## AD/YA-1/1","sortOrder":1},{"sectionNumber":"Main Landing Gear TopAttachment Bolts - ","sectionType":"part","heading":"Main Landing Gear TopAttachment Bolts - Replacement","content":"## Main Landing Gear Top  \nAttachment Bolts - Replacement","sortOrder":2},{"sectionNumber":"8/2022","sectionType":"part","heading":"8/2022","content":"## 8/2022","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a straightforward re-making of an existing Airworthiness Directive to prevent it from lapsing. The scope remains exactly as originally intended: mandatory bolt replacement for Yeoman YA-1 aircraft. The background explicitly states this is an administrative reissue under Part 39 of CASR, not an expansion of regulatory scope."},"complexity_factors":["Very short document (approximately 300 words)","Only 2 defined compliance pathways based on a single historical modification status","No nested exceptions or conditional logic beyond the binary modified/unmodified distinction","Single substantive requirement (bolt replacement) with straightforward time intervals","Minimal cross-referencing (only references one Service Bulletin and the Civil Aviation Safety Regulations)"],"plain_english_summary":"This AD requires owners/operators of Yeoman Aircraft YA‑1 aeroplanes in Australia to replace the bolts attaching the main landing gear on a mandated schedule to prevent structural failure. \n\nCompliance timing differs by modification status: unmodified aircraft require bolt replacement within 90 days and every 100 flight hours thereafter; aircraft modified per the 1963 service bulletin require replacement within 90 days and every 750 flight hours. The AD was reissued in 2022 to restore an expired safety requirement."},"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The re‑made AD restates the original technical requirement to replace the main landing gear top attachment bolts and applies to the same population (\"All models of Yeoman Aircraft YA-1 series aircraft\"). The Background explains the AD was reissued because the prior AD lapsed under the Legislation Act 2003 after a YA‑1 returned to the Australian register; there is no indication in the text that the substantive scope or compliance obligations were changed."},"complexity_factors":["Broad applicability: covers \"All models of Yeoman Aircraft YA-1 series aircraft\" (Applicability).","Conditional compliance regimes: two different recurrent intervals depending on whether the aircraft was modified per \"Yeoman Aircraft Service Bulletin (SB) YA1-SB002 dated 25 February 1963\" (Compliance).","Mixed time constraints: an initial fixed calendar deadline (\"Within 90 days after the commencement date of this AD\") plus ongoing requirements tied to aircraft hours in service (100 or 750 hours) (Compliance).","Normative reference and proof burden: compliance depends on records or evidence that the SB modification was installed as \"in force on the commencement date of this AD,\" creating a documentary/inspection task for operators (Compliance).","Regulatory provenance and restart: AD was re‑made under Part 39 of CASR because the prior AD had lapsed when an example returned to the Australian register, which affects legal force but not the substantive technical requirement (Background).","Operational impact: requirement imposes maintenance actions, parts procurement and aircraft downtime on operators (Requirement; Compliance).","Single administrative start date: AD \"commences on 29 April 2022,\" fixing the trigger for the 90‑day window and record assessments (Compliance)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of all Yeoman Aircraft YA‑1 series aeroplanes to replace the original main landing gear top attachment bolts. It sets a 90‑day initial compliance deadline and recurring work measured in hours‑in‑service, with shorter intervals for aircraft that have not been modified in accordance with Yeoman Service Bulletin YA1‑SB002. The AD was reissued because a YA‑1 returned to the Australian register after the prior AD lapsed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement","history":"/api/acts/ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement/history","analysis":"/api/acts/ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement/analysis","conflicts":"/api/acts/ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement/conflicts","importantCases":"/api/acts/ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement/important-cases","documents":"/api/acts/ad-ya-1-1-main-landing-gear-top-attachment-bolts-replacement/documents"}}