{"id":"F2006B06049","name":"AD/PAP/5 Amdt 2 - Propeller Fixed Spline - Inspection and Replacement","slug":"ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114447,"registerId":"commonwealth-F2006B06049-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PAP/5 Amdt 2 - Propeller Fixed Spline - Inspection and Replacement","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPropellers \\- Variable Pitch \\- Allison/Aeroproducts\n\nAD/PAP/5\n\nAmdt 2\n\n  \n\nPropeller Fixed Spline \\- Inspection and Replacement\n\n  \n10/67\n\nApplicability: All Allison/Aeroproducts propellers model A6441 FN-606 and A6441 FN-606A fitted with fixed splines P/No.653110, P/No. 6509978, P/No. 6508538 or P/No. 6522974 S/No. 1367 and subsequent.\n\nRequirement: 1. (a) Inspect propellers and mark in accordance with Allison telegram THO-641W- LOD dated 7.4.1967 and modified by Allison telegram THO-662W-LOD dated 10.4.1967.\n\n(b) Carry out a double static feather and static reverse check consisting of two complete consecutive cyles in accordance with the referenced Allison telegrams.\n\n2. Remove from service, all fixed splines P/nos. 6523110, 6509978 and 6508538, and fixed splines P/No. 6522974 S/No. 1367 and up which do meet the specification requirements for core hardness as specified in Allison Commercial SL 189 Page 7 Para. B4C.\n\nCompliance: For para. 1. (a) \\- Within 10 hours time in service after 1 November 1967.\n\nFor para. 1. (b) \\- Daily until the requirements of para. 2 have complied with. For para. 2 - Before 1st November, 1967.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing Airworthiness Directive (AD/PAP/5). The scope remains tightly focused on the original safety issue regarding fixed spline inspection and replacement for specific Allison/Aeroproducts propellers. There is no indication of scope creep; the amendment appears to update or clarify the existing requirements rather than expand them to new aircraft types or unrelated safety issues."},"complexity_factors":["Short, single-purpose directive with only 2 main requirements","Limited applicability — only 2 specific propeller models and 4 specific part numbers","References external documents (Allison telegrams and Service Letter 189) without reproducing their content","Simple conditional logic: daily testing required only until compliance with removal requirement is achieved","No nested definitions or extensive interpretation sections","Straightforward compliance dates with clear deadlines"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspection/marking of specific Allison/Aeroproducts propellers (A6441 FN-606/A) with listed fixed-spline part numbers, daily double-static feather and reverse checks, and removal of spline parts that fail core-hardness requirements. \n\nIt applies to operators of affected propellers and matters because soft or defective splines can cause propeller failure in flight, risking loss of control, engine damage, or a crash."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Marked as 'Amdt 2', this version establishes specific inspection, marking and repeated test requirements plus removal criteria tied to core‑hardness for listed spline part/serial numbers. Compared with the original AD identifier, it adds or clarifies concrete procedural steps and firm compliance dates (see title and Requirement/Compliance sections)."},"complexity_factors":["Technical references to external documents: two Allison telegrams (THO-641W-LOD, THO-662W-LOD) and Allison Commercial SL 189 Page 7 Para. B4C (Requirement paras 1(a), 1(b), 2).","Multiple specific part numbers and serial-number thresholding for applicability and removal (Applicability; Requirement para.2).","Procedural requirements include marking, and a specialised double static feather and static reverse check of two consecutive cycles (Requirement para.1(b)).","Staggered and tight compliance deadlines (within 10 hours after 1 Nov 1967; daily checks until replacement; removal before 1 Nov 1967) creating operational scheduling pressure (Compliance).","Ambiguous wording in the removal clause about core‑hardness ('which do meet the specification requirements') increases interpretation risk for maintainers and regulators (Requirement para.2).","Administrative burden on operators to track compliance status daily and to source and fit replacement splines where required."],"plain_english_summary":"This airworthiness directive requires operators of Allison/Aeroproducts propellers model A6441 FN-606 and A6441 FN-606A with the listed fixed spline part and serial numbers to mark and inspect the propellers, perform consecutive double static‑feather and static‑reverse checks, and remove specified spline parts from service depending on measured core hardness (per Allison Commercial SL 189). It matters because affected operators must carry out tests, apply markings and replace parts within short, specified timeframes (see Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement","history":"/api/acts/ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement/history","analysis":"/api/acts/ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement/important-cases","documents":"/api/acts/ad-pap-5-amdt-2-propeller-fixed-spline-inspection-and-replacement/documents"}}