{"id":"F2007L02195","name":"AD/ATR 42/5 - Main Landing Gear Side Brace Assembly","slug":"ad-atr-42-5-main-landing-gear-side-brace-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":67441,"registerId":"commonwealth-F2007L02195-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Avions de Transport Regional ATR 42 Seri","sectionType":"division","heading":"Avions de Transport Regional ATR 42 Series Aeroplanes","content":"### Avions de Transport Regional ATR 42 Series Aeroplanes\n\n| AD/ATR 42/5 | Main Landing Gear Side Brace Assembly | 8/2007 |\n| ----------- | ------------------------------------- | ------ |\n\n| Applicability: | Model ATR 42-200, -300, and -320 aircraft, all serial numbers, with main landing gear fitted with side brace assemblies part number D22710000 not incorporating suffix -8 (ATR modification 8346 - MESSIER DOWTY Service Bulletin631-32-176); and equipped with upper arm part number D56778-10.                                                          |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the requirements of DGAC AD F-2005-106.Note: MESSIER DOWTY Service Bulletin 631-32-181 Revision 2, or later EASA approved revision, refers.                                                                                                                                                                                     |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of2 August 2007.                                                                                                                                                                                                                                                                  |\n|                | This Airworthiness Directive becomes effective on 2 August 2007.                                                                                                                                                                                                                                                                                          |\n| Background:    | A report was received of a MLG unlock warning indication on an ATR aircraft during taxi operation. Inspection found that the upper MLG side brace assembly was cracked. Investigation revealed that crack propagation occurred at a corrosion pit on the surface under the part identification plate. This Directive requires visual and NDT inspections. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n22 June 2007","sortOrder":0},{"sectionNumber":"AD/ATR 42/5","sectionType":"part","heading":"AD/ATR 42/5","content":"## AD/ATR 42/5","sortOrder":1},{"sectionNumber":"Main Landing Gear Side Brace Assembly","sectionType":"part","heading":"Main Landing Gear Side Brace Assembly","content":"## Main Landing Gear Side Brace Assembly","sortOrder":2},{"sectionNumber":"8/2007","sectionType":"part","heading":"8/2007","content":"## 8/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The technical scope of the directive is consistent with the referenced DGAC AD F-2005-106 and the Messier Dowty service bulletin: it mandates inspections of specified parts on specified ATR 42 variants. The only explicit administrative change noted in the text is a revised effective date of 2 August 2007; no expansion or narrowing of the described applicability or inspection requirement is stated."},"complexity_factors":["Narrow, parts‑specific applicability: applies only to ATR 42-200/-300/-320 aircraft with side brace P/N D22710000 (not incorporating suffix -8) and upper arm P/N D56778-10 — requires accurate fleet records to determine applicability.","Requires non‑destructive testing (NDT) in addition to visual inspection — creates need for specialist skills, equipment and scheduling.","Cross‑referenced mandatory materials: compliance is to be \"in accordance with the requirements of DGAC AD F-2005-106\" and refers to MESSIER DOWTY Service Bulletin 631-32-181 Revision 2 (or later EASA approved revision) — operators must obtain and follow external documents.","Potential direct costs to operators for inspections, possible repair or part replacement following findings — financial and operational impact on airlines and maintenance organisations.","Timing/administration: Compliance statement includes a revised effective date of 2 August 2007, affecting implementation planning.","Regulatory decision and enforcement are by the Civil Aviation Safety Authority (document signed by the CASA Delegate) — central regulator imposes the compliance requirement.","Detection difficulty: root cause identified as crack propagation from a corrosion pit under the part identification plate, implying inspections must address hidden corrosion risks and ensure adequate inspection coverage and techniques.","Recordkeeping and continuing airworthiness obligations follow from the AD structure — operators must document inspections and any corrective actions."],"plain_english_summary":"This directive requires operators of ATR 42-200, -300 and -320 aeroplanes fitted with main landing gear side brace assembly P/N D22710000 (without suffix -8) and upper arm P/N D56778-10 to perform visual and non‑destructive inspections for cracking and corrosion. It follows a report of a crack originating at a corrosion pit and mandates compliance with DGAC AD F-2005-106 and MESSIER DOWTY Service Bulletin 631-32-181 Revision 2 (or later EASA‑approved revision). The directive took effect on 2 August 2007."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical defect in a defined aircraft population. The scope remains precisely focused on the original safety issue — cracked main landing gear side brace assemblies — without expansion into unrelated systems or broader operational requirements."},"complexity_factors":["Highly specific applicability criteria requiring cross-referencing of multiple part numbers (D22710000 without suffix -8, D56778-10)","References to external documents (DGAC AD F-2005-106, Messier Dowty Service Bulletin 631-32-181) without reproducing their content","Technical aviation terminology (NDT, MLG, side brace assembly, modification suffixes)","Nested conditions: applicability depends on aircraft model AND specific part numbers AND absence of specific modification","Short length (under 500 words) but dense with conditional logic"],"plain_english_summary":"This AD mandates inspections (visual and NDT) of the main landing gear side‑brace assembly on certain ATR 42‑200/300/320 aircraft fitted with side brace P/N D22710000 (no “‑8”) and upper arm P/N D56778‑10, after a corrosion‑hidden crack was found. It affects operators of those ATR 42s, references DGAC and Messier‑Dowty guidance, and aims to prevent landing‑gear failure; compliance was required by 2 August 2007."},"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-atr-42-5-main-landing-gear-side-brace-assembly","history":"/api/acts/ad-atr-42-5-main-landing-gear-side-brace-assembly/history","analysis":"/api/acts/ad-atr-42-5-main-landing-gear-side-brace-assembly/analysis","conflicts":"/api/acts/ad-atr-42-5-main-landing-gear-side-brace-assembly/conflicts","importantCases":"/api/acts/ad-atr-42-5-main-landing-gear-side-brace-assembly/important-cases","documents":"/api/acts/ad-atr-42-5-main-landing-gear-side-brace-assembly/documents"}}