{"id":"F2007L01446","name":"AD/AS 355/95 - Fuselage Centre Cross-Member under Cabin Floor","slug":"ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":65848,"registerId":"commonwealth-F2007L01446-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Eurocopter AS 355 (Twin Ecureuil) Series","sectionType":"division","heading":"Eurocopter AS 355 (Twin Ecureuil) Series Helicopters","content":"### Eurocopter AS 355 (Twin Ecureuil) Series Helicopters\n\n| AD/AS 355/95 | Fuselage Centre Cross-Memberunder Cabin Floor | 7/2007 TX |\n| ------------ | --------------------------------------------- | --------- |\n\n| Applicability: | Model AS355 E, F, F1, F2 and N helicopters, all serial numbers, delivered before1 January 2007, and equipped with collective-to-yaw control coupling with or without an Automatic Flight Control System.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Confirm installation of the cross-member at station X 2165 and of the doublers at stations X 2325 and Y 269 as detailed in the Accomplishment Instructions paragraph of Eurocopter Alert Service Bulletin (ASB) 53.00.23 original issue, or later EASA approved revision.If the cross-member and the doublers are installed, no further action is required.2. If the cross-member and/or doublers are not installed, check for cracks by a visual or a dye penetrant inspection, the centre cross-member at station X 2325, in the area around the attachment point of the tail rotor directional ball-type control as detailed in the Accomplishment Instructions paragraph of ASB 53.00.23 original issue, or later EASA approved revision.If no cracking is detected:Before further flight, check the tail rotor control rigging in accordance with the Accomplishment Instructions paragraph of ASB 53.00.23 original issue, or later EASA approved revision.Repeat the Requirement 2 inspection until Requirement 3 is accomplished.If any crack is detected:Flight is prohibited.3. Install the cross-member at station X 2165 and the doublers at stations X 2325 and Y 269, in accordance with the Appendix paragraph of ASB 53.00.23 original issue, or later EASA approved revision.Note: EASA Emergency AD 2007-0139-E refers. |\n\n| Compliance: | For Requirements 1 and 2: Within 10 flight hours or 1 month after 18 May 2007, whichever occurs first. Repeat the Requirement 2 inspection at intervals not to exceed 55 flight hours; until accomplishment of Requirement 3.Requirement 3: Within 12 months after 18 May 2007.                                                                                                                                                                                                                                                                                                                                  |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Airworthiness Directive becomes effective on 18 May 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n| Background: | The EASA received a report of a crack in the area of the centre cross-member at station X 2325, at the attachment point of the yaw channel ball-type control sheath stop of a Model AS 355 N helicopter fitted with the collective-to-yaw control coupling. Investigation revealed that the helicopter was not equipped with the structure doublers, which are combined with the collective-to-yaw control coupling installation. Repetitive overloads on the non-modified cross member will cause it to crack, and result in reduction of yaw control travel with consequent reduced yaw control for the pilot. |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n16 May 2007","sortOrder":0},{"sectionNumber":"AD/AS 355/95","sectionType":"part","heading":"AD/AS 355/95","content":"## AD/AS 355/95","sortOrder":1},{"sectionNumber":"Fuselage Centre Cross-Memberunder Cabin ","sectionType":"part","heading":"Fuselage Centre Cross-Memberunder Cabin Floor","content":"## Fuselage Centre Cross-Member  \nunder Cabin Floor","sortOrder":2},{"sectionNumber":"7/2007 TX","sectionType":"part","heading":"7/2007 TX","content":"## 7/2007 TX","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":4,"scope_assessment":{"changed":false,"description":"The instrument targets a specific safety risk (cracking at the centre cross‑member where the yaw control attaches) for a defined subset of AS355 helicopters and prescribes inspections and a retrofit. The text does not indicate an expansion or narrowing of that original safety focus; it implements corrective inspections and mandatory installation per Eurocopter ASB and refers to the related EASA Emergency AD."},"complexity_factors":["Conditional workflow: different actions depending on presence/absence of the cross‑member and doublers (Requirement 1–3).","Cross‑references to external technical material (Eurocopter ASB 53.00.23 original issue or later EASA‑approved revisions) for inspection and installation procedures.","Repetitive inspection regime with a specified maximum interval (repeat Requirement 2 at intervals not to exceed 55 flight hours) until modification is completed.","Hard safety control: discovery of any crack mandates immediate flight prohibition (Requirement 2).","Multiple compliance timeframes: short‑term checks (10 flight hours or 1 month) and longer‑term mandatory installation (12 months).","Applicability limits: specific helicopter models/serials delivered before 1 Jan 2007 and only those equipped with collective‑to‑yaw control coupling.","Technical specificity: inspections tied to precise fuselage stations (X 2165, X 2325, Y 269) and attachment points, increasing reliance on calibrated maintenance resources.","Regulatory layering: references both CASA effective date and an EASA Emergency AD (2007‑0139‑E), creating parallel oversight and approval dependencies."],"plain_english_summary":"This Airworthiness Directive requires operators of Eurocopter AS355 E/F/F1/F2/N helicopters delivered before 1 January 2007 with collective‑to‑yaw coupling to check whether a fuselage centre cross‑member and reinforcing doublers are fitted. If they are missing, operators must inspect the cross‑member for cracks repeatedly (until modification), check tail‑rotor control rigging, ground any helicopter with a detected crack, and install the cross‑member and doublers within 12 months following the Eurocopter service instructions approved by EASA/CASA. The aircraft operator bears inspection and modification costs; CASA/EASA enforce conformity."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a focused, single-purpose scope: addressing a specific structural defect in a defined helicopter fleet. The scope remains tightly constrained to the fuselage centre cross-member issue and does not expand beyond the original safety concern."},"complexity_factors":["Multiple conditional pathways (if installed → stop; if not installed → inspect; if cracked → ground aircraft; if not cracked → repeat inspection)","Cross-references to external technical document (Eurocopter Alert Service Bulletin 53.00.23) for detailed instructions","Dual compliance timelines (flight hours OR calendar time for initial action; flight hours for repeats; calendar time for final action)","Specific technical terminology requiring aviation engineering knowledge (station X 2165, station X 2325, station Y 269, doublers, dye penetrant inspection)","Applicability criteria combining model variants, serial numbers, delivery dates, and equipment configurations"],"plain_english_summary":"This AD targets Eurocopter AS355 (E, F, F1, F2, N) helicopters delivered before 1 Jan 2007 with collective-to-yaw coupling. Owners/operators must verify whether a fuselage cross‑member reinforcement is installed, inspect for cracking (grounding aircraft if cracks are found), and install the reinforcement within 12 months, with short‑interval inspections until the permanent fix is completed."}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor","history":"/api/acts/ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor/history","analysis":"/api/acts/ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor/analysis","conflicts":"/api/acts/ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor/conflicts","importantCases":"/api/acts/ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor/important-cases","documents":"/api/acts/ad-as-355-95-fuselage-centre-cross-member-under-cabin-floor/documents"}}