{"id":"F2006B06350","name":"AD/PROP/2 Amdt 2 - Feathering Propellers - Functional Check","slug":"ad-prop-2-amdt-2-feathering-propellers-functional-check","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47562,"registerId":"commonwealth-F2006B06350-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PROP/2 Amdt 2 - Feathering Propellers - Functional Check","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 \\- General\n\nAD/PROP/2\n\nAmdt 2\n\n  \nFeathering Propellers \\- Functional Check 11/94\n\nApplicability: All feathering propellers fitted to piston engine aircraft, except powered gliders.\n\nRequirement: Conduct a ground functional check to ensure the propellers will fully feather within the aircraft manufacturer's specified time limits.\n\nCompliance: At intervals not exceeding 100 hours time in service or 12 calendar months, whichever occurs first. This amendment becomes effective from 13 October 1994.\n\nNote: For further information on the requirement to check the feathering ability of propellers refer old series Airworthiness Advisory Circular No 117-3.\n\nBackground: 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. The previous amendment incorporates manufacturers' time limits to the feathering check while this amendment introduces an annual inspection requirement.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1646},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of ensuring feathering capability but adds a calendar-based inspection interval (12 months) to complement the existing flight hours interval (100 hours). The scope remains focused on functional checks of feathering propellers for piston aircraft."},"complexity_factors":["Short, single-purpose directive with clear applicability","Only one exemption category (powered gliders)","Simple dual-interval compliance calculation (flight hours vs calendar months)","No cross-references to other legislative instruments","Plain language background section explains technical rationale"],"plain_english_summary":"**What this is:** A safety rule requiring regular checks of aircraft propellers to ensure they can 'feather' properly.\n\n**What is 'feathering'?** When an aircraft engine fails, the propeller blades need to turn sideways (like a weather vane) to stop creating drag and allow the plane to glide safely. This is called 'feathering'.\n\n**Who it affects:** Owners and operators of piston-engine aircraft with feathering propellers. Powered gliders are exempt.\n\n**What must be done:** Every 12 months or every 100 flight hours (whichever comes first), a mechanic must perform a ground test to verify the propeller can fully feather within the time limit set by the manufacturer.\n\n**Why it matters:** If a propeller cannot feather during an engine failure, it creates significant drag that can make the aircraft difficult or impossible to control. Regular testing also helps prevent oil sludge buildup and keeps blade bearings lubricated."}},"importantCases":[],"_links":{"self":"/api/acts/ad-prop-2-amdt-2-feathering-propellers-functional-check","history":"/api/acts/ad-prop-2-amdt-2-feathering-propellers-functional-check/history","analysis":"/api/acts/ad-prop-2-amdt-2-feathering-propellers-functional-check/analysis","conflicts":"/api/acts/ad-prop-2-amdt-2-feathering-propellers-functional-check/conflicts","importantCases":"/api/acts/ad-prop-2-amdt-2-feathering-propellers-functional-check/important-cases","documents":"/api/acts/ad-prop-2-amdt-2-feathering-propellers-functional-check/documents"}}