{"id":"F2006B06328","name":"AD/PR/29 Amdt 5 - Operating Cylinder Retaining Bolts","slug":"ad-pr-29-amdt-5-operating-cylinder-retaining-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47489,"registerId":"commonwealth-F2006B06328-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PR/29 Amdt 5 - Operating Cylinder Retaining Bolts","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 \\- Dowty Rotol\n\nAD/PR/29\n\nAmdt 5\n\n  \nOperating Cylinder Retaining Bolts 2/94\n\nApplicability: R352/6-123-F/1 and R352/6-123-F/2 propellers bearing Serial Nos \"DRG\" or with Serial No prior to DAP 0064 fitted to Fokker F27 Mk 50 aircraft.\n\nRequirement: 1. Action in accordance with Dowty Aerospace Gloucester mandatory Service Bulletin No F50-61-93 Revision 1 or F50-61-67 Revision 2, as applicable.\n\n2. Unless previously carried out action in accordance with Dowty Aerospace Gloucester mandatory Service Bulletin F50-61-108.\n\nNote: RLD AD BLA 91-135/2 (A), RLD AD BLA 93-130 (A) and Fokker SB F50-61-\n\n016 refers.\n\nCompliance: 1. At intervals not exceeding 500 hours time in service until Dowty Aerospace Gloucester SB F50-61-108, modification VP3460, has been incorporated.\n\n2. By 31 December 1994.\n\nBackground: There has been reports of propeller operating cylinder retaining bolts, P/N A102-3J, P/N A212-3J or P/N A212-5J, losing torque during normal service with one reported incident of oil leakage from the hub to cylinder interface. This directive raised in sequence to provide terminating action for this directive and include R352/6-123-F/2 propellers.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 5 to an existing Airworthiness Directive. The amendment adds R352/6-123-F/2 propellers to the applicability and introduces a terminating action (modification VP3460) to end the repetitive inspection requirement. This represents a natural evolution of the safety measure rather than scope creep — the core purpose (addressing loose retaining bolts) remains unchanged."},"complexity_factors":["Single, specific mechanical issue addressed (loose retaining bolts)","Limited applicability: only two propeller models on one aircraft type","Clear two-part compliance structure (interim inspections + terminating action)","Only 3 part numbers referenced","No nested definitions or extensive cross-referencing to other legislation","Self-contained document with explicit deadlines and service bulletin references"],"plain_english_summary":"Australia’s Civil Aviation Safety Authority requires operators of Fokker F27 Mk 50 aircraft with certain Dowty Rotol propellers (models R352/6-123-F/1 and F/2, serials beginning “DRG” or older than DAP 0064) to inspect and replace operating cylinder retaining bolts (A102-3J, A212-3J, A212-5J) that have been found to lose torque.\n\nInspections are to be repeated every 500 flight hours until the permanent modification VP3460 (per Service Bulletin F50-61-108) is fitted by 31 Dec 1994 to prevent oil loss or propeller failure."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The directive was revised to add R352/6-123-F/2 propellers to the applicability and to provide a terminating modification (VP3460) via Dowty SB F50-61-108; earlier versions did not include that propeller series or the specified terminating action."},"complexity_factors":["Multiple referenced Dowty Aerospace Gloucester mandatory Service Bulletins (F50-61-93 Rev 1, F50-61-67 Rev 2, F50-61-108) that determine specific work","Applicability limited to particular propeller models and serial-number ranges (R352/6-123-F/1 and R352/6-123-F/2 bearing \"DRG\" or prior to DAP 0064)","Two-tier compliance regime: recurring inspections at intervals (<=500 hours TIS) until a terminating modification (VP3460) is incorporated","Fixed deadline for terminating action (31 December 1994)","Cross-references to other ADs and service bulletins (RLD AD BLA 91-135/2 (A), RLD AD BLA 93-130 (A), Fokker SB F50-61-016) requiring coordination of compliance sources"],"plain_english_summary":"This airworthiness directive requires inspections and corrective action on specific Dowty Rotol variable-pitch propellers fitted to Fokker F27 Mk 50 aircraft, addressing loss of torque in operating-cylinder retaining bolts and a reported oil leak. It mandates following particular Dowty Aerospace Gloucester mandatory Service Bulletins and repeating actions every 500 flight hours until a specified modification (VP3460) is installed, with the final terminating modification required by 31 December 1994.\n\nIt affects operators of the listed propeller serial numbers and imposes recurring compliance work and a one‑time modification to eliminate the fault."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pr-29-amdt-5-operating-cylinder-retaining-bolts","history":"/api/acts/ad-pr-29-amdt-5-operating-cylinder-retaining-bolts/history","analysis":"/api/acts/ad-pr-29-amdt-5-operating-cylinder-retaining-bolts/analysis","conflicts":"/api/acts/ad-pr-29-amdt-5-operating-cylinder-retaining-bolts/conflicts","importantCases":"/api/acts/ad-pr-29-amdt-5-operating-cylinder-retaining-bolts/important-cases","documents":"/api/acts/ad-pr-29-amdt-5-operating-cylinder-retaining-bolts/documents"}}