{"id":"F2006B05322","name":"AD/P166/29 - Flap Hinge Attachment At Rib No. 13","slug":"ad-p166-29-flap-hinge-attachment-at-rib-no-13","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":45775,"registerId":"commonwealth-F2006B05322-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/P166/29 - Flap Hinge Attachment At Rib No. 13","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)  \nPiaggio P166 Series Aeroplanes\n\nAD/P166/29 Flap Hinge Attachment At Rib No. 13 5/64\n\nApplicability: All models prior to S/No. 410.\n\nRequirement: 1. Inspect the flap hinge attachment at rib number 13 for cracking at the following components: The attaching plate of the hinge bracket, the web of the dummy spar, the flanges of the joint plate and the dummy spar post. Piaggio SL 166-9 refers. If cracking is found modify in accordance with para. 2 before further flight.\n\n    2. Modify in accordance with Piaggio SB No. P166.38.\n\n    3. RAI AD 64-26, P166-23, Rev. 1 also refers.\n\nCompliance: Para. 1 \\- Within the next 100 hours time in service and thereafter at intervals not exceeding 100 hours time in service until modified.\n\nPara. 2 \\- For aircraft that have exceeded 2,000 hours time in service \\- by 1 November 1964; For aircraft not exceeding 2,000 hours time in service - at the first routine inspection following the aircraft reaching 2,500 hours time in service.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a narrow, targeted safety directive addressing a specific known defect in a specific aircraft model. The scope remains tightly focused on the original safety issue without expansion into broader operational or regulatory matters."},"complexity_factors":["Single, specific mechanical component addressed (flap hinge at rib 13)","Only 3 main requirements with clear sequential logic (inspect → modify if cracked → permanent modification)","4 specific inspection locations explicitly listed","Simple compliance timeline based on flight hours and calendar date","References to external technical documents (Piaggio Service Bulletins) rather than internal cross-references","No defined terms section, no nested exceptions, no conditional sub-clauses"],"plain_english_summary":"This is an **Airworthiness Directive** — 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 **Piaggio P166 series aeroplanes** (specifically those built before serial number 410) to inspect and potentially repair a critical part of the wing flap system.\n\n**The safety problem:**\nThe **flap hinge attachment at rib number 13** can develop cracks in several connected metal parts. Flaps are the moveable surfaces on the back of wings that help aircraft slow down for landing. If this hinge fails, the pilot could lose control of the flaps — a serious safety risk.\n\n**What must be done:**\n- **Inspection:** Check the hinge attachment for cracks in four specific areas (the attaching plate, web, flanges, and dummy spar post). This must happen within the next 100 hours of flying time, then repeated every 100 hours until repairs are done.\n- **Repair:** If cracks are found, the aircraft cannot fly again until modified according to Piaggio Service Bulletin P166.38.\n- **Permanent fix:** All high-time aircraft (over 2,000 flight hours) must be modified by 1 November 1964. Lower-time aircraft must be modified when they reach 2,500 flight hours.\n\n**Who it affects:**\nAnyone who owns, operates, or maintains early-model Piaggio P166 aircraft in Australia.\n\n**Why it matters:**\nThis directive prevents potential structural failure that could lead to loss of aircraft control. Compliance is legally mandatory — flying without completing these requirements violates civil aviation law."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive stays within the original safety scope: inspect and, if necessary, modify the flap hinge attachment on Piaggio P166 aircraft prior to S/No. 410. It does not broaden to other parts or aircraft types; it prescribes inspection cadence and modification deadlines tied to airframe hours, consistent with the stated airworthiness aim."},"complexity_factors":["Safety‑critical structural inspection of multiple, specific components (attaching plate, dummy spar web, joint plate flanges, dummy spar post)","Repeated 100‑hour inspection interval continuing until modification — ongoing operational burden","Tiered mandatory modification deadlines tied to different hours‑in‑service thresholds (2,000 vs 2,500 hours)","Applicability limited by serial-number cutoff (pre S/No. 410), requiring fleet tracking","Cross‑references to a manufacturer Service Bulletin (Piaggio SB P166.38) and other ADs (RAI AD 64‑26, P166‑23 Rev.1) — dependency on external documents for compliance details","Potential immediate grounding risk if cracking is found (modification required before further flight), creating logistical and cost consequences"],"plain_english_summary":"Requires owners/operators of Piaggio P166 aeroplanes (serial numbers before 410) to inspect the flap hinge attachment at rib No.13 for cracking and to modify the structure if cracks are found. Inspections must occur every 100 flight hours until the modification is completed, and mandatory modification deadlines are set by total hours-in-service. It affects aircraft operators who must carry out periodic inspections and pay for any required structural modification to keep the aircraft airworthy."}},"importantCases":[],"_links":{"self":"/api/acts/ad-p166-29-flap-hinge-attachment-at-rib-no-13","history":"/api/acts/ad-p166-29-flap-hinge-attachment-at-rib-no-13/history","analysis":"/api/acts/ad-p166-29-flap-hinge-attachment-at-rib-no-13/analysis","conflicts":"/api/acts/ad-p166-29-flap-hinge-attachment-at-rib-no-13/conflicts","importantCases":"/api/acts/ad-p166-29-flap-hinge-attachment-at-rib-no-13/important-cases","documents":"/api/acts/ad-p166-29-flap-hinge-attachment-at-rib-no-13/documents"}}