{"id":"F2006B06050","name":"AD/PAP/6 Amdt 2 - Installation Of Increase Pitch Metering Restrictor","slug":"ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114448,"registerId":"commonwealth-F2006B06050-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PAP/6 Amdt 2 - Installation Of Increase Pitch Metering Restrictor","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 - Allison/Aeroproducts\n\n \n\nAD/PAP/6\n\nAmdt 2\n\n\nInstallation Of Increase Pitch Metering Restrictor 11/67\n\n \n\nApplicability: All model A6441 FN-606 and A6441 FN-606A fitted with assemblies specified in Allison Commercial Propeller Bulletin No. 63-310.\n\n \n\nDocument: Allison SPB No. 63-310. Compliance: Before 1 November 1967.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, targeted safety directive focused on a specific mechanical defect in specific propeller models. It has not expanded beyond its original purpose of mandating a single hardware modification."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 2 specific propeller models affected","Single technical requirement with no exceptions or conditions","No defined terms section","No cross-references to other legislation beyond the manufacturer bulletin","Simple compliance deadline structure","No nested logic or procedural steps"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by the Civil Aviation Safety Authority (CASA) that requires aircraft owners or operators to make specific repairs or modifications to keep their aircraft safe to fly.\n\n**What it does:** This directive orders the **installation of an \"increase pitch metering restrictor\"** — a mechanical component that limits how far a propeller's blade angle (pitch) can increase. This prevents the propeller from going into too coarse a pitch, which could cause engine damage or loss of control.\n\n**Who it affects:** Owners and operators of specific Allison/Aeroproducts propeller models:\n- **A6441 FN-606**\n- **A6441 FN-606A**\n\n—but **only** if those propellers are fitted with the assemblies described in **Allison Commercial Propeller Bulletin No. 63-310**.\n\n**When it had to be done:** Before **1 November 1967**.\n\n**Why it matters:** Propeller pitch controls how much air the propeller bites — too much pitch can overload the engine or cause the propeller to \"feather\" (stop producing thrust) unexpectedly. This AD prevents mechanical failures that could lead to engine damage or forced landings.\n\n**Key point:** This is a **historical directive** from 1967. It shows how aviation safety works — when manufacturers discover a design flaw, CASA issues binding orders to fix it before accidents happen."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The available text specifies applicability (particular propeller models and assemblies), references the Allison service publication for installation, and sets a compliance date. The instrument as provided does not include earlier or alternative operative language against which to detect a change of scope; therefore there is no information in the text to show that the scope has changed from any prior instrument."},"complexity_factors":["Narrow technical scope limited to two propeller model numbers (low breadth). (Applicability)","Relies on an external technical publication (Allison SPB No. 63-310) for installation details, requiring access to, and interpretation of, specialised maintenance instructions. (Document)","Safety-critical hardware change requiring certified maintenance actions and potential aircraft downtime (technical/operational complexity). (Document & Compliance)","Fixed compliance deadline creates scheduling and logistical pressures for owners and maintenance providers. (Compliance)","The AD text does not set out enforcement, exemption or record-keeping detail, leaving implementation practice to regulator and maintenance standards (administrative ambiguity)."],"plain_english_summary":"This directive mandates fitting an \"increase pitch metering restrictor\" to Allison/Aeroproducts propellers model A6441 FN-606 and A6441 FN-606A when they have the assemblies identified in Allison SPB No. 63-310. Owners/operators must perform the retrofit per that bulletin before 1 November 1967; they bear parts, labour, scheduling and downtime costs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor","history":"/api/acts/ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor/history","analysis":"/api/acts/ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor/analysis","conflicts":"/api/acts/ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor/conflicts","importantCases":"/api/acts/ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor/important-cases","documents":"/api/acts/ad-pap-6-amdt-2-installation-of-increase-pitch-metering-restrictor/documents"}}