{"id":"F2006B01817","name":"AD/A109/31 - Main Rotor Blade NDI","slug":"ad-a109-31-main-rotor-blade-ndi","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41015,"registerId":"commonwealth-F2006B01817-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/A109/31 - Main Rotor Blade NDI","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)  \nAgusta A109 Series Helicopters\n\nAD/A109/31 Main Rotor Blade NDI 13/99\n\nApplicability: Model A109A and 109AII with Main Rotor Blades P/N109-0103-01-(all), excepting\n\n\\-115 blades.\n\nRequirement: Carry out NDI inspections in accordance with Bollettino Technico No.109-111 dated 14 October 1999.\n\nNote: RAI AD No. 99-413 refers.\n\nCompliance: For Part 1 Radiographic, before 30 May 2000 then at intervals no greater than 2 years.\n\nFor Part 2 \\- which is indicated by the results of Part 1; for the specified :\n\n    Eddy Current inspection, at intervals not exceeding 25 hours time in service, or\n\n    b. Liquid Penetrant inspection, at intervals not exceeding 10 hours time in service.\n\nThis Airworthiness Directive becomes effective on 30 December 1999.\n\nBackground: Destructive inspection of life expired MR Blades removed from service revealed corrosion in the area adjacent to the balancing inertia weight (STA 1354 and STA 2825). This Directive prescribes an inspection utilising the radiographic method to determine the serviceability of blades and if necessary a continuing regime of either eddy current or dye penetrant inspections.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The directive's scope is confined to specified A109 models and blade part numbers (Applicability) and prescribes inspections targeted at corrosion adjacent to the balancing inertia weights (Background). The measures align with that stated purpose and do not expand applicability beyond those blades or introduce unrelated obligations."},"complexity_factors":["Applicability specificity: limited to Models A109A/109AII with blades P/N109-0103-01, excluding -115 (Applicability) — requires accurate fleet parts tracking.","Layered inspection regime: initial radiographic inspection plus conditional continuing inspections (Requirement; Compliance) — creates decision points and follow-up logistics.","Divergent repetition rates: radiography every 2 years vs. eddy current every 25 hours TIS or penetrant every 10 hours TIS (Compliance) — operational and scheduling complexity for operators.","External normative reference: compliance mandated to Bollettino Technico No.109-111 dated 14 Oct 1999 (Requirement) — reliance on a separate technical document for procedures.","Short lead/compliance dates: initial radiography due before 30 May 2000 and AD effective 30 Dec 1999 (Compliance; Effective date) — compressed implementation window.","Technical inspection methods: radiography, eddy current and dye penetrant require specialised equipment and qualified technicians (Requirement; Compliance) — increases maintenance cost and supply reliance.","Conditionality based on inspection results: Part 2 inspections only if Part 1 indicates (Compliance) — adds monitoring and record-keeping burden.","Cross-references: Note to RAI AD No. 99-413 (Note) — administrative cross-checking may be required."],"plain_english_summary":"Requires operators of Agusta A109A and 109AII helicopters fitted with main rotor blades P/N 109-0103-01 (except -115) to carry out non‑destructive inspections under Bollettino Technico No.109-111 (14 Oct 1999). A radiographic check must be done before 30 May 2000 and then no more than every two years; if indications appear, a continuing regime of either eddy‑current (≤25 hrs TIS) or liquid‑penetrant (≤10 hrs TIS) inspections is required. The directive follows discovery of corrosion near the balancing inertia weights."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete Airworthiness Directive with a single, focused safety purpose. It has not expanded beyond its original intent — to mandate specific corrosion inspections on specific helicopter rotor blades following the discovery of a safety defect."},"complexity_factors":["Short, single-purpose document (1 page)","Only 4 defined elements: applicability (model/part numbers), two-part inspection requirement, compliance intervals, and effective date","Simple conditional logic: Part 2 inspections only triggered if Part 1 results indicate need","No cross-references to other legislation (only a note referencing related Italian aviation authority document)","Clear, technical but straightforward language aimed at aircraft maintenance engineers"],"plain_english_summary":"Owners/operators of Agusta A109A and A109AII helicopters with affected main rotor blades must perform mandatory non‑destructive inspections for hidden corrosion. A radiographic (X‑ray) inspection is required by 30 May 2000 and every two years thereafter; if corrosion is found, follow‑up checks using eddy current (every 25 flight hours) or liquid penetrant (every 10 flight hours) are required. This AD addresses corrosion near balancing weights that could cause catastrophic blade failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a109-31-main-rotor-blade-ndi","history":"/api/acts/ad-a109-31-main-rotor-blade-ndi/history","analysis":"/api/acts/ad-a109-31-main-rotor-blade-ndi/analysis","conflicts":"/api/acts/ad-a109-31-main-rotor-blade-ndi/conflicts","importantCases":"/api/acts/ad-a109-31-main-rotor-blade-ndi/important-cases","documents":"/api/acts/ad-a109-31-main-rotor-blade-ndi/documents"}}