{"id":"F2006B05477","name":"AD/PA-23/50 Amdt 1 - Flap Control System and Bellcrank - Inspection","slug":"ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":46277,"registerId":"commonwealth-F2006B05477-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-23/50 Amdt 1 - Flap Control System and Bellcrank - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Piper PA-23 (Apache and Aztec) Series Aeroplanes\n\n \n\nAD/PA-23/50\n\nAmdt 1\n\n\nFlap Control System and Bellcrank - Inspection 4/81\n\n \n\nApplicability: All models PA-23/PA-23-160, PA-23-235, PA-23-250 and PA-23-250 (6 place) with S/Nos. prior to 27-8054060.\n\n \n\nDocument: Piper SB No. 671.\n\n \n\nNote: FAA AD 81-04-05 amendment 39-4040 also refers.\n\n \n\nCompliance:  Unless already accomplished, initially inspect within 100 hours time in service after achieving 1000 hours time in service since manufacture and thereafter at intervals not exceeding 500 hours time in service until modified in accordance with Piper SB 671.\n\n \n\nBackground:  Reports received by the manufacturer indicate that cracks may develop in the flap control system components after 1000 hours time in service.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive focused on a specific safety-critical mechanical defect in a particular aircraft type. The scope remains tightly constrained to flap system inspections for the identified Piper models, with no evidence of scope creep beyond the original safety purpose."},"complexity_factors":["Single, specific mechanical system addressed (flap control)","Clear applicability criteria (specific aircraft models and serial number cutoff)","Simple compliance timeline (initial inspection at 1,000 hours + 100 hours, then recurring every 500 hours)","Only one cross-reference (to FAA AD 81-04-05 for additional context)","No defined terms section or complex conditional logic","Straightforward termination condition (compliance with Piper SB 671)"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires owners and operators of specific Piper aircraft to inspect their flap control systems for dangerous cracks.\n\n**What it does:**\n- Requires visual inspections of the **flap control system and bellcrank** (the mechanical parts that move the wing flaps) on certain Piper Apache and Aztec aeroplanes\n- Mandates these inspections after the aircraft reaches 1,000 flight hours, then every 500 flight hours thereafter\n- Continues until the aircraft is permanently modified according to manufacturer's Service Bulletin 671\n\n**Who it affects:**\n- Owners and operators of Piper PA-23 series aircraft (Apache and Aztec models) with serial numbers before 27-8054060\n- Specifically covers: PA-23, PA-23-160, PA-23-235, PA-23-250, and PA-23-250 (6 place) models\n\n**Why it matters:**\n- Cracks in flap control components can cause **loss of flap control** — meaning pilots might be unable to extend or retract flaps for takeoff and landing\n- This creates serious safety risks during critical flight phases\n- The directive is legally enforceable; non-compliance can ground an aircraft or result in penalties\n\n**Key compliance deadline:**\n- First inspection required within 100 flight hours after the aircraft hits 1,000 total flight hours, then every 500 hours until fixed"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This entry is labelled 'Amdt 1', indicating it amends a prior AD. The supplied text itself sets out the inspection intervals and the pathway to end recurring inspections (modification per Piper SB No. 671). The specific differences between this amendment and the original AD are not contained in the supplied text, so the exact nature of the change cannot be determined from this document alone. (Amdt 1; Compliance; Document)"},"complexity_factors":["Limited, well‑defined applicability by model and serial number (Applicability)","Simple, fixed inspection intervals tied to time‑in‑service milestones (Compliance)","Dependency on an external technical document (Piper SB No. 671) for the modification that removes recurring inspections (Document)","Need for accurate tracking of airframe hours and maintenance records to meet timing requirements (Compliance)","Reference to an FAA AD for related material, creating a small cross‑document compliance requirement (Note)"],"plain_english_summary":"Owners/operators of specified Piper PA‑23 (Apache/Aztec) aircraft (S/N before 27‑8054060) must begin inspections of the flap control system and bellcrank after the aeroplane reaches 1,000 hours TIS: an initial check within 100 hours thereafter and every 500 hours until the plane is modified per Piper SB No. 671. The rule responds to reported cracking, shifts inspection costs to owners, and gives an incentive to adopt the SB modification to eliminate recurring inspections."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection","history":"/api/acts/ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection/history","analysis":"/api/acts/ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection/analysis","conflicts":"/api/acts/ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection/conflicts","importantCases":"/api/acts/ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection/important-cases","documents":"/api/acts/ad-pa-23-50-amdt-1-flap-control-system-and-bellcrank-inspection/documents"}}