{"id":"F2007L02268","name":"AD/A109/58 - Lower Semichannel Assemblies of the Forward Firewall","slug":"ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":67530,"registerId":"commonwealth-F2007L02268-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Agusta A109 Series Helicopters","sectionType":"division","heading":"Agusta A109 Series Helicopters","content":"### Agusta A109 Series Helicopters\n\n| AD/A109/58 | Lower Semichannel Assembliesof the Forward Firewall | 9/2007 DM |\n| ---------- | --------------------------------------------------- | --------- |\n\n| Applicability: | Model A109E helicopters, with serial numbers up to and including 11694, except serial numbers 11633 and 11634.Model A109S helicopters, with serial numbers up to and including 22034, except 22026 and 22033.                                                                                                                              |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Action in accordance with Agusta Alert Technical Bulletin (BT) No. 109EP-79 or BT No. 109S-15, as applicable.Note: EASA Emergency AD 2007-0192-E refers.                                                                                                                                                                                   |\n| Compliance:    | Within 20 flight hours after 18 July 2007, but not later than 30 September 2007; unless already accomplished.                                                                                                                                                                                                                              |\n|                | This Airworthiness Directive becomes effective on 18 July 2007.                                                                                                                                                                                                                                                                            |\n| Background:    | Interference between the forward firewall metallic spacer part number109-0642-01-195 and the main drive shaft part number 109-0415-06-103 has been detected on Model 109LUH helicopters. Damage to the main drive shaft, unless detected and corrected, could result in failure of the drive shaft and consequent loss of controllability. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n16 July 2007","sortOrder":0},{"sectionNumber":"AD/A109/58","sectionType":"part","heading":"AD/A109/58","content":"## AD/A109/58","sortOrder":1},{"sectionNumber":"Lower Semichannel Assembliesof the Forwa","sectionType":"part","heading":"Lower Semichannel Assembliesof the Forward Firewall","content":"## Lower Semichannel Assemblies  \nof the Forward Firewall","sortOrder":2},{"sectionNumber":"9/2007 DM","sectionType":"part","heading":"9/2007 DM","content":"## 9/2007 DM","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text contains no indication that the directive amends or narrows a prior measure. It sets a clear, single‑issue scope—specified A109E/A109S serial numbers (with listed exceptions) and a corrective action per Agusta technical bulletins—to address detected interference between a firewall spacer and the main drive shaft (Applicability; Requirement; Background)."},"complexity_factors":["Narrow, serial-number-based applicability with explicit exceptions (Applicability)","Mandatory compliance tied to external manufacturer technical bulletins (Requirement)","Short, two-tier compliance window (within 20 flight hours after 18 July 2007; no later than 30 Sep 2007) creating scheduling pressures (Compliance)","Safety-critical mechanical interaction requiring technical inspection/repair (Background)","Cross-reference to an external regulator's Emergency AD (EASA Emergency AD 2007-0192-E) increases regulatory interdependence (Requirement/Background)","Effective date specified, so non‑compliance has immediate operational impact (Compliance/Effective date)"],"plain_english_summary":"Mandates inspection and corrective action per Agusta Alert Technical Bulletin BT No. 109EP‑79 or 109S‑15 for specified Agusta A109E and A109S helicopters to address interference between a forward firewall spacer and the main drive shaft. Operators of the listed serial-numbered aircraft must complete the work within 20 flight hours after 18 July 2007 and by 30 September 2007 (Applicability; Requirement; Compliance). The measure aims to prevent drive‑shaft damage that could lead to loss of control (Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 250 words)","Only 2 defined applicability criteria (serial number ranges for two helicopter models)","Single, unambiguous compliance requirement referencing external technical bulletins","No nested exceptions or conditional logic beyond basic serial number exclusions","Clear, single deadline with simple alternative (already accomplished)","No cross-references to other legislation beyond noting related EASA directive"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection and repair of a forward‑firewall spacer (P/N 109‑0642‑01‑195) that is rubbing the main drive shaft (P/N 109‑0415‑06‑103) on certain Agusta A109E and A109S helicopters. It affects A109E serials up to 11694 (except 11633, 11634) and A109S serials up to 22034 (except 22026, 22033). Operators must follow Agusta technical bulletins (BT 109EP‑79 / BT 109S‑15) within 20 flight hours after 18 Jul 2007 or by 30 Sep 2007."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall","history":"/api/acts/ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall/history","analysis":"/api/acts/ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall/analysis","conflicts":"/api/acts/ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall/conflicts","importantCases":"/api/acts/ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall/important-cases","documents":"/api/acts/ad-a109-58-lower-semichannel-assemblies-of-the-forward-firewall/documents"}}