{"id":"F2006B06321","name":"AD/PR/22 - Pitch Lock Cylinder and Support Sleeves - Inspection","slug":"ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47465,"registerId":"commonwealth-F2006B06321-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PR/22 - Pitch Lock Cylinder and Support Sleeves - Inspection","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Propellers - Variable Pitch - Dowty Rotol\n\n \n\nAD/PR/22 Pitch Lock Cylinder and Support NK\n\nSleeves - Inspection\n\n \n\nApplicability: All propeller models R179/4-30-4/33, R184/4-30-4/50, R193/4-30-4/50 and /61, R209/4-40-4.5/2, R245/4-40-4.5/13, R257/4-30-4/60, R259/4-40-4.5/17, modified in\n\naccordance with Mod. No. (c) VP 2833 (SB 61-838).\n\n \n\nRequirement: IAW Dowty Rotol SB No. 61-906, Rev. 1.\n\n \n\nCompliance: Before installation in an aircraft following next reconditioning completed after 31 January 1979.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The AD applies to the listed propeller models modified per Mod. No. (c) VP 2833 and requires inspection per Dowty Rotol SB No. 61-906, Rev. 1, before installation after the next reconditioning completed after 31 January 1979. The text contains no indication that the scope has been altered from the instrument as presented."},"complexity_factors":["Narrow technical applicability: multiple specific propeller model numbers and a modification reference must be checked (Applicability).","Dependency on an external service bulletin for procedure: Dowty Rotol SB No. 61-906, Rev. 1 contains the inspection steps (Requirement).","Timing rule tied to reconditioning completion dates: compliance triggers are phrased as \"next reconditioning completed after 31 January 1979\", requiring record checks and potential interpretation (Compliance).","Operational impact: inspection is a precondition to installation, which can cause scheduling and downtime for operators (Compliance + Requirement).","Regulatory formality: issued under Civil Aviation Regulations 1998, PART 39 - 107, giving it mandatory AD status and concentrating legal obligation on operators/maintainers (header)."],"plain_english_summary":"# What this instrument changes mechanically\n\nThis airworthiness directive (AD) requires an inspection of the pitch lock cylinder and support sleeves on a specified set of Dowty Rotol variable-pitch propellers. The inspection must be carried out in accordance with Dowty Rotol Service Bulletin No. 61-906, Rev. 1 (text cited as the \"Requirement\"). The AD applies only to the propeller models listed under \"Applicability\" and only to units modified in accordance with Mod. No. (c) VP 2833 (SB 61-838). The timing rule is: the inspection must be performed before the propeller is installed in an aircraft after the next reconditioning that was completed after 31 January 1979 (text cited as the \"Compliance\").\n\n# Who this affects and who decides\n\n- Decision-maker: The directive is issued under the Commonwealth instrument listing (Civil Aviation Regulations 1998, PART 39 - 107) and therefore has regulatory force as an AD (header text).  \n- Affected parties who pay and must act: owners, operators and maintenance organisations that hold, service, recondition or install the specified propeller models (the list of models appears under \"Applicability\"). They must obtain and follow Dowty Rotol SB No. 61-906, Rev. 1 to perform the inspection (\"Requirement\").\n\n# Why it matters (official claim and practical mechanics)\n\n- Official claim: the AD text sets an inspection requirement (the directive does not itself state a narrative safety rationale beyond the inspection title and the requirement citation). The instrument directs compliance with the named service bulletin (\"Requirement\").\n- Practical mechanics: affected propellers must be identified (by model and by whether they were modified per Mod. No. (c) VP 2833 / SB 61-838), reconditioning records checked to determine whether reconditioning was completed after 31 January 1979, and the inspection per SB 61-906 Rev. 1 performed before the next installation.\n\n# Costs, incentives and trade-offs (source-grounded)\n\n- Who pays: the operator or maintenance organisation performing reconditioning or installation bears the direct cost of obtaining the service bulletin and performing the inspection (this follows from the Requirement and Compliance lines).  \n- Incentives created: compliance is required before installation after reconditioning (Compliance). That makes timely inspection a precondition for returning a propeller to service, creating an incentive to schedule inspections alongside reconditioning.  \n- Compliance burden and implementation risk: the directive depends on an external document (Dowty Rotol SB No. 61-906, Rev. 1) for the inspection procedure (Requirement). Affected parties must: (a) verify applicability against the model list and modification number (Applicability), (b) confirm reconditioning completion dates (Compliance), and (c) perform the specified inspection steps in the service bulletin. These steps create administrative work (record checks), potential downtime while inspection is done, and reliance on availability of the service bulletin and any necessary parts or tooling.  \n- Bureaucratic discretion and procedural clarity: the AD points to a single service bulletin for mandatory procedure (Requirement), and the compliance timing is tied to a specific date and the event \"next reconditioning\" (Compliance). That concentrates decision authority on the regulator to require the inspection and on the manufacturer document for the means of compliance, while leaving operators to apply those instructions in practice.\n\n# Effects on private choice and operations\n\n- Operators choose when to recondition and when to install; the AD conditions installation after reconditioning on completion of the inspection (Compliance). This constrains the sequence of maintenance tasks and may shift scheduling and costs to operators and MROs.  \n- The AD is narrowly targeted by model and modification number (Applicability), so it affects only holders of those specific propellers.\n\n# Concrete citations to the source text\n\n- Authority/format: \"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES\" (header).  \n- Title: \"AD/PR/22 Pitch Lock Cylinder and Support Sleeves - Inspection\".  \n- Applicability: \"All propeller models R179/4-30-4/33, R184/4-30-4/50, R193/4-30-4/50 and /61, R209/4-40-4.5/2, R245/4-40-4.5/13, R257/4-30-4/60, R259/4-40-4.5/17, modified in accordance with Mod. No. (c) VP 2833 (SB 61-838).\"  \n- Requirement: \"IAW Dowty Rotol SB No. 61-906, Rev. 1.\"  \n- Compliance: \"Before installation in an aircraft following next reconditioning completed after 31 January 1979.\""},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical issue in specific propeller models. It has not expanded beyond its original purpose of ensuring pitch lock cylinder integrity in modified Dowty Rotol propellers."},"complexity_factors":["Single, specific technical requirement referencing an external manufacturer document (Dowty Rotol SB 61-906)","Limited applicability: only 8 specific propeller models with one specific modification","Clear, single-date compliance trigger (post-31 January 1979 reconditioning)","No nested exceptions, conditional logic, or defined terms section","Standard AD format with four standard fields: Applicability, Requirement, Compliance, and reference to external technical standard"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA). It mandates a specific safety inspection for certain Dowty Rotol aircraft propellers.\n\n**What it does:**\n- Requires inspection of the **pitch lock cylinder and support sleeves** on specific propeller models\n- The inspection must follow the manufacturer's Service Bulletin (SB 61-906, Revision 1)\n\n**Who it affects:**\n- Owners and operators of aircraft with these specific Dowty Rotol propeller models: R179/4-30-4/33, R184/4-30-4/50, R193/4-30-4/50 and /61, R209/4-40-4.5/2, R245/4-40-4.5/13, R257/4-30-4/60, and R259/4-40-4.5/17\n- **Only applies to propellers modified** according to Modification VP 2833 (Service Bulletin 61-838)\n\n**When compliance is required:**\n- Before installing the propeller in an aircraft, following the next reconditioning completed after **31 January 1979**\n\n**Why it matters:**\nAirworthiness Directives are legally binding safety orders. They address unsafe conditions in aircraft, engines, or propellers. This directive prevents potential failures in the propeller's pitch control mechanism — a critical system that adjusts blade angle for flight efficiency and safety. Non-compliance means the aircraft cannot legally fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection","history":"/api/acts/ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection/history","analysis":"/api/acts/ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection/analysis","conflicts":"/api/acts/ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection/conflicts","importantCases":"/api/acts/ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection/important-cases","documents":"/api/acts/ad-pr-22-pitch-lock-cylinder-and-support-sleeves-inspection/documents"}}