{"id":"F2016L00157","name":"AD/PROP/2 Amdt 4 - Feathering Propellers - Functional Check","slug":"ad-prop-2-amdt-4-feathering-propellers-functional-check","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":94027,"registerId":"commonwealth-F2016L00157-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Propellers - General","sectionType":"division","heading":"Propellers - General","content":"### Propellers - General\n\n| AD/PROP/2 Amdt 4 | Feathering Propellers - Functional Check | 5/2016 |\n| ---------------- | ---------------------------------------- | ------ |\n\n| Applicability: | All feathering propellers fitted to piston engine aircraft to which Part 42 of CASR 1998 applies.                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Conduct a ground functional check to ensure the propellers will fully feather within the aircraft manufacturer's specified time limits.                                                                                                                                                                                                                                                                                                                                                                            |\n| Compliance:    | At intervals not exceeding 110 hours time in service or 12 calendar months, whichever occurs first.                                                                                                                                                                                                                                                                                                                                                                                                                |\n|                | The effective date of this AD is 26 February 2016.                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | To ensure propellers are capable of feathering when required, a ground functional check is introduced. Regular feathering of propellers will reduce the engine oil sludge build up in the propeller dome and aid in redistribution of grease in blade bearings.Amendment 1 incorporated manufacturers' time limits to the feathering check.Amendment 2 introduced an annual inspection requirement.Amendment 3 increased the hourly interval to 110 hours to align the interval with common maintenance intervals. |\n|                | Amendment 4 is issued to limit the applicability of the AD to Part 42 aircraft only. This AD will be repealed after the requirements are incorporated into a future amendment of the Part 42 Manual of Standards.                                                                                                                                                                                                                                                                                                  |\n\n![VAN DIJK_P](image.001.jpeg)\n\nPieter van Dijk  \nDelegate of the Civil Aviation Safety Authority\n\n22 February 2016","sortOrder":0},{"sectionNumber":"AD/PROP/2 Amdt 4","sectionType":"part","heading":"AD/PROP/2 Amdt 4","content":"## AD/PROP/2 Amdt 4","sortOrder":1},{"sectionNumber":"Feathering Propellers - Functional Check","sectionType":"part","heading":"Feathering Propellers - Functional Check","content":"## Feathering Propellers - Functional Check","sortOrder":2},{"sectionNumber":"5/2016","sectionType":"part","heading":"5/2016","content":"## 5/2016","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 4 narrowed the AD’s applicability to only aircraft certificated under CASR Part 42 (previous versions applied more broadly). The AD remains in force until its requirements are incorporated into a future amendment of the Part 42 Manual of Standards (Background)."},"complexity_factors":["Narrow applicability to Part 42 certificated piston‑engine aircraft (Applicability) — reduces stakeholder scope but requires cross‑checking aircraft certification.","Fixed compliance interval (110 hours or 12 months) (Compliance) — simple periodicity but may not align with every operator’s maintenance cycles.","Requirement to meet manufacturer feathering time limits (Requirement) — depends on varied OEM specifications rather than a single technical standard.","Regulatory lifecycle note (Background) — AD will be repealed after incorporation into Part 42 Manual of Standards, creating a transitional compliance/recording obligation.","Amendment history and prior changes (Background) — multiple past amendments incorporated different requirements, so operators must confirm the current text applies."],"plain_english_summary":"This Airworthiness Directive requires operators of piston‑engine aircraft certificated under CASR Part 42 to run a ground functional check of feathering propellers to confirm they fully feather within the aircraft manufacturer’s time limits, every 110 flight hours or 12 months (whichever comes first). The stated purpose is to reduce oil sludge and redistribute grease in the propeller dome. The recurring maintenance time and cost fall on aircraft owners/operators; the AD’s applicability has been narrowed to Part 42 aircraft and will be repealed once incorporated into the Part 42 Manual of Standards."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":true,"description":"The original directive applied broadly to feathering propellers on piston-engine aircraft. Amendment 4 significantly narrowed the scope to apply only to Part 42 aircraft — those operating under CASA's approved maintenance organisation system. This excludes private operators and smaller operations not under Part 42. The amendment also signals an intent to eventually repeal this standalone directive entirely and absorb its requirements into the Part 42 Manual of Standards, representing a shift from individual ADs to consolidated standards."},"complexity_factors":["Very short document (approximately 300 words)","Only 4 defined elements: applicability, requirement, compliance, and background","Single straightforward obligation with clear time-based trigger (110 hours/12 months)","No cross-references to other legislation beyond 'Part 42 of CASR 1998' and 'Part 42 Manual of Standards'","No conditional logic or exceptions — the requirement applies uniformly to all covered aircraft","Plain language background section explains rationale in accessible terms"],"plain_english_summary":"This AD mandates regular ground functional checks of feathering propellers on piston‑engine aircraft regulated under Part 42 to confirm blades can fully feather within manufacturer time limits. It targets aircraft with feathering props to ensure readiness in the event of an engine failure.\n\nChecks are required every 110 flight hours or 12 months, whichever comes first, to prevent oil/sludge build‑up and bearing issues. This fourth version narrows applicability to Part 42 aircraft and will be folded into the Part 42 Manual of Standards in future."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-prop-2-amdt-4-feathering-propellers-functional-check","history":"/api/acts/ad-prop-2-amdt-4-feathering-propellers-functional-check/history","analysis":"/api/acts/ad-prop-2-amdt-4-feathering-propellers-functional-check/analysis","conflicts":"/api/acts/ad-prop-2-amdt-4-feathering-propellers-functional-check/conflicts","importantCases":"/api/acts/ad-prop-2-amdt-4-feathering-propellers-functional-check/important-cases","documents":"/api/acts/ad-prop-2-amdt-4-feathering-propellers-functional-check/documents"}}