{"id":"F2006B02517","name":"AD/AS 355/68 - \"TRW-SAMM\" Main Servocontrols","slug":"ad-as-355-68-trw-samm-main-servocontrols","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41773,"registerId":"commonwealth-F2006B02517-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nEurocopter AS 355 (Twin Ecureuil) Series Helicopters","sortOrder":0},{"sectionNumber":"AD/AS 355/68 “TRW-SAMM” Main Servocontro","sectionType":"part","heading":"AD/AS 355/68 “TRW-SAMM” Main Servocontrols 10/2002","content":"# AD/AS 355/68 “TRW-SAMM” Main Servocontrols 10/2002\n\nApplicability: AS 355 helicopters version F, F1, F2, and N equipped with “TRW-SAMM’ main servocontrols Part Number (P/N) SC 8042 or SC 8043 which underwent their last complete overhaul or repair since overhaul at “HAWKER PACIFIC AEROSPACE’, USA before March 1 2002.\n\nRequirement: Remove the servocontrols and return them to “HAWKER PACIFIC AEROSPACE” for a check of the thread condition and application torque as required in Eurocopter AS 355 Alert Telex No. 67.00.23.\n\nNote: DGAC 2002-315-069(A).\n\nCompliance: 1. For servocontrols held as spares; prior to fitment to an aircraft.\n\n    2. For servocontrols that have been in service for less than 1000 flight hours since overhaul; within 550 flight hours or 3 October 2003, whichever comes first.\n\n    3. For servocontrols that have been in service between 1000 and 1300 flight hours since overhaul; prior to 1550 flight hours or 3 July 2003, whichever comes first.\n    4. For servocontrols that have been in service for more than 1300 flight hours since overhaul; within 250 flight hours or 3 March 2003 whichever comes first.\n\nThis Airworthiness Directive becomes effective on 3 October 2002.\n\nBackground: An incorrect torque loading was found to have been applied to the end fitting that attaches the servocontrol cylinder to the upper ball end fitting. The incorrect torque may lead to failure of the threads on the fitting, leading to separation of the upper-end fitting and result in loss of control of the helicopter.\n\n![](image.002.png)  \n\nJames Coyne\n\n![](image.001.png)  \nDelegate of the Civil Aviation Safety Authority 23 August 2002\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 September 2002.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The directive is corrective and narrowly targeted to servocontrols meeting the specified part numbers and overhaul/repair history; it does not expand beyond that original corrective objective. It prescribes inspections/returns and staged compliance timings rather than broadening applicability or adding unrelated obligations."},"complexity_factors":["Technical subject-matter: inspection of thread condition and application torque on helicopter servocontrol end fittings.","Narrow, technical applicability: limited to AS 355 F/F1/F2/N with specific part numbers and a cutoff date for last overhaul/repair.","Multiple staged compliance windows based on flight hours since overhaul and separate rule for spares, increasing tracking burden.","Requirement to return units to a named overseas organisation (Hawker Pacific Aerospace, USA) for checks, creating logistical and cost implications.","Cross-reference to external manufacturer guidance (Eurocopter Alert Telex No. 67.00.23) and foreign authority note (DGAC 2002-315-069(A)).","Safety-critical consequence (possible loss of control) raising urgency and limiting discretionary deviation from requirements."],"plain_english_summary":"This Airworthiness Directive orders removal and return of specific TRW‑SAMM main servocontrols (P/N SC 8042 or SC 8043) fitted to Eurocopter AS 355 F/F1/F2/N helicopters if those units were last overhauled or repaired at Hawker Pacific (USA) before 1 March 2002. Operators and maintenance organisations must send affected units to Hawker Pacific for thread-condition and torque checks within staged deadlines tied to hours since overhaul or before fitment.\n\nThe measure addresses an identified incorrect torque on the end fitting that can cause thread failure and separation of the upper‑end fitting, risking loss of control; compliance imposes inspection, removal, and logistical costs on operators and maintenance providers."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It targets a specific unsafe condition in specific helicopter models with specific parts from a specific maintenance provider during a specific timeframe. There is no evidence of scope creep; the directive remains tightly focused on the identified torque defect."},"complexity_factors":["Multiple conditional compliance deadlines based on flight hours since overhaul (4 separate categories)","Specific part number identification required (P/N SC 8042 or SC 8043)","Reference to external technical document (Eurocopter AS 355 Alert Telex No. 67.00.23) without reproducing its contents","Cross-reference to French aviation authority notice (DGAC 2002-315-069(A))","Specific applicability criteria combining aircraft model, version, component type, manufacturer, and date threshold"],"plain_english_summary":"This safety order requires owners/operators of Eurocopter AS 355 Twin Ecureuil helicopters fitted with certain servocontrols last overhauled by Hawker Pacific Aerospace before 1 March 2002 to remove and return those units for thread inspection and correct torquing. \n\nA manufacturing/overhaul error (incorrectly tightened bolt) can cause servocontrol failure and loss of control, so the order imposes mandatory inspections and corrective action within specified timeframes based on hours since overhaul."}},"importantCases":[],"_links":{"self":"/api/acts/ad-as-355-68-trw-samm-main-servocontrols","history":"/api/acts/ad-as-355-68-trw-samm-main-servocontrols/history","analysis":"/api/acts/ad-as-355-68-trw-samm-main-servocontrols/analysis","conflicts":"/api/acts/ad-as-355-68-trw-samm-main-servocontrols/conflicts","importantCases":"/api/acts/ad-as-355-68-trw-samm-main-servocontrols/important-cases","documents":"/api/acts/ad-as-355-68-trw-samm-main-servocontrols/documents"}}