{"id":"F2006B09856","name":"AD/F50/3 Amdt 1 - Wing Structure - Skin Splice WS 7915","slug":"ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54934,"registerId":"commonwealth-F2006B09856-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/3 Amdt 1 - Wing Structure - Skin Splice WS 7915","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)  \nFokker F50 (F27 Mk 50) Series Aeroplanes\n\nAD/F50/3\n\nAmdt 1\n\n  \nWing Structure \\- Skin Splice WS 7915 4/89\n\nApplicability: F27-050 S/Nos 20103 to 20108 and 20110 to 20127.\n\nRequirement: 1. Restrict Vmo in accordance with Fokker Telefax ME 88.5877 dated 29 June 1988 until modified in accordance with Fokker S.B. F50/57-001.\n\nNote: Speed restriction may be achieved by placing placards adjacent to ASIs and including the Fokker Temporary Change in the Flight Manual.\n\n2. Action in accordance with Fokker S B F50-57-001 Rev 1.\n\nNote: RLD BLA 88-54 part 3 refers.\n\nCompliance: 1. Before further flight after 1 July 1988.\n\n2. Prior to 31 December 1989.\n\nBackground: The manufacturer has determined that due to faulty heat treatment the strength of the skin splice at WS 7900 is less than specified. Amdt 1 includes terminating modification action.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 modifies the original directive by adding a terminating modification action and specifying the Service Bulletin revision as the means of termination. The AD requires an immediate speed restriction (telefax) until the structural modification described in Fokker S.B. F50-57-001 Rev 1 is completed, and sets a final compliance date for that modification (Requirement 1; Requirement 2; Background; Compliance 1–2)."},"complexity_factors":["Narrow applicability limited to specific serial numbers (reduces scope complexity) (Applicability).","Two-step compliance: immediate operational restriction and later structural modification (Requirement 1–2; Compliance 1–2).","Dependence on external manufacturer documents (Fokker Telefax and Service Bulletin Rev 1) for technical detail (Requirement notes; Requirement 2).","Explicit short-term and medium-term compliance deadlines (Compliance 1 and Compliance 2).","Multiple ways allowed to achieve the speed restriction (placards and Flight Manual change) which require operational and administrative coordination (Note to Requirement 1)."],"plain_english_summary":"This directive imposes an immediate reduced maximum operating speed on specified Fokker F50 (F27 Mk 50) serials because a wing skin splice was found understrength. Operators must placard and insert a temporary Flight Manual change now, and complete a manufacturer’s structural modification by 31 Dec 1989. The Civil Aviation Safety Authority enforces the rule; operators bear the compliance costs, downtime and maintenance required to remove the restriction."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific manufacturing defect on a limited batch of aircraft. It has not expanded beyond its original safety purpose. Amendment 1 merely adds the terminating action (the permanent fix) to the original directive, which is a natural completion of the regulatory response rather than scope creep."},"complexity_factors":["Very short document (under 300 words)","Only 4 defined elements: applicability (specific serial numbers), requirement (2 numbered actions), compliance dates, and background","No cross-references to other legislation — only references to manufacturer documents (Fokker telefax and service bulletin)","Simple conditional logic: speed restriction applies 'until modified', with clear termination condition","Single purpose: address one specific manufacturing defect on one aircraft type"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Fokker F50 aeroplanes to fix a dangerous manufacturing defect in the wing structure. The skin splice (a joint where two pieces of the aircraft's outer wing skin are joined together) at a specific location called \"WS 7915\" was improperly heat-treated during manufacturing, making it weaker than it should be.\n\n**Who it affects:**\nOnly specific Fokker F50 aircraft with serial numbers 20103 to 20108 and 20110 to 20127 — a limited batch of planes.\n\n**What must be done:**\n- **Immediately:** Reduce the maximum operating speed (Vmo) of the aircraft until repairs are made. This is done by placing warning labels next to the airspeed indicators and updating the flight manual.\n- **By end of 1989:** Carry out permanent structural modifications according to the manufacturer's service bulletin (Fokker S.B. F50/57-001).\n\n**Why it matters:**\nA weak wing skin splice could lead to structural failure in flight. This directive ensures the aircraft remain safe to fly while forcing a permanent fix within a set timeframe. Amendment 1 (Amdt 1) specifically adds the requirement for the terminating modification — meaning once the repair is done, the speed restriction can be lifted."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915","history":"/api/acts/ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915/history","analysis":"/api/acts/ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915/analysis","conflicts":"/api/acts/ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915/conflicts","importantCases":"/api/acts/ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915/important-cases","documents":"/api/acts/ad-f50-3-amdt-1-wing-structure-skin-splice-ws-7915/documents"}}