{"id":"F2006B05711","name":"AD/PA-31/123 - Wing Spar Splice Plate (Navajo)","slug":"ad-pa-31-123-wing-spar-splice-plate-navajo","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135510,"registerId":"commonwealth-F2006B05711-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-31/123 - Wing Spar Splice Plate (Navajo)","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)  \nPiper PA-31 Series Aeroplanes\n\nAD/PA-31/123 Wing Spar Splice Plate (Navajo) 13/94 DM\n\nApplicability: All Piper Navajo PA-31, PA-31/A1, PA-31-300 and PA-31-325.\n\nRequirement: Remove from service the splice plate which joins the wing main spar lower cap at the aircraft centre line, in accordance with the compliance detailed below.\n\nReport as a major defect any fretting, corrosion or crack found in the splice plate upon removal. Retain the defective splice plate for investigation.\n\nCompliance: 1. Subject to paragraphs 2. and 3. below, remove from service splice plates which have achieved 6000 hours time in service (TIS), or 1500 hours TIS after the splice plate was inspected as part of the Gippsland Aeronautics main spar modification (see AD/PA-31/37), whichever is the later.\n\n    2. For splice plates that have exceeded the above limit by less than 1000 hours, as at 31 October 1994, remove before 31 January 1995.\n\n    3. For splice plates that have exceeded the above limit by more than 1000 hours, as at 3 October 1994, remove before 30 November 1994.\n\nNote: On application to the Authority, a longer life may be approved for new splice plates installed in a manner that prevents fretting and corrosion.\n\nBackground: Fatigue cracks have been found in the splice plate which joins the lower caps of the wing main spars. In addition to flight loads, contributors to the cracking are residual tensile stresses, fretting and corrosion.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":3282},"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope addressing the specific fatigue cracking defect in wing spar splice plates of the specified Piper Navajo aircraft models. No expansion into unrelated aircraft systems or additional model variants is evident."},"complexity_factors":["Cross-reference to previous directive AD/PA-31/37 for calculating compliance hours","Conditional compliance using 'whichever is the later' logic between two hour thresholds","Tiered historical deadlines based on extent of hour limit breach (less than 1000 vs more than 1000 hours)","Technical aviation terminology and abbreviations (TIS, spar, splice plate, fretting)"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Piper Navajo PA-31 variants to remove and replace the metal splice plate that joins the wing main spars at the centerline, after 6,000 flight hours or 1,500 hours following the prior inspection—whichever is later—due to fatigue cracking from stress, corrosion, and fretting that can weaken the wing.\n\nIf cracks, corrosion, or fretting are found, they must be reported as major defects and the part retained; operators may seek CASA approval for an alternate longer‑life plate if it prevents fretting and corrosion."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-31-123-wing-spar-splice-plate-navajo","history":"/api/acts/ad-pa-31-123-wing-spar-splice-plate-navajo/history","analysis":"/api/acts/ad-pa-31-123-wing-spar-splice-plate-navajo/analysis","conflicts":"/api/acts/ad-pa-31-123-wing-spar-splice-plate-navajo/conflicts","importantCases":"/api/acts/ad-pa-31-123-wing-spar-splice-plate-navajo/important-cases","documents":"/api/acts/ad-pa-31-123-wing-spar-splice-plate-navajo/documents"}}