{"id":"F2006B06188","name":"AD/PHS/11 Amdt 1 - Blade Retaining Rings","slug":"ad-phs-11-amdt-1-blade-retaining-rings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47048,"registerId":"commonwealth-F2006B06188-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PHS/11 Amdt 1 - Blade Retaining Rings","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 \\- Hamilton Standard\n\nAD/PHS/11\n\nAmdt 1\n\n  \nBlade Retaining Rings 13/88\n\nApplicability: All Model 14SF-5 and 14SF-7 propellers fitted to, but not limited to, De Havilland Dash 8 and Aerospatiale ATR 42 aircraft.\n\nRequirement: 1. Inspect the plastic “Rynite” blade retaining rings on all four blades in accordance with Hamilton Standard Alert Service Bulletin 14SF-61-A21 Revision 2. Blade retaining rings with evidence of cracks require removal of both halves from service before further flight and replacement with new retaining ring halves in accordance with ASB 14SF-61-A21 Revision 2.\n\n2. Replace the plastic “Rynite” blade retaining rings P/N 785540 with aluminium blade retaining rings P/N 794345 on all four blades, in accordance with Hamilton Standard SB 14SF-61-17 Revision 1.\n\nNote: FAA AD 88-20-08 Amdt 39-6009 refers.\n\nCompliance: 1. Inspect within 50 hours time in service after 22 June 1987 and thereafter at intervals not exceeding 200 hours time in service.\n\n2. Prior to 31 July 1989.\n\nBackground: Loss of the plastic “Rynite” retaining ring may cause severe damage to the blade retention system caused by the subsequent propeller vibration.\n\nThis Amendment is raised to introduce terminating action.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly focused on its original purpose: addressing a specific safety defect in Hamilton Standard propeller blade retaining rings. The amendment introduces 'terminating action' (the permanent aluminium replacement), which was the intended end-state of the original directive. The scope has not expanded beyond the specific propeller models and aircraft types originally identified."},"complexity_factors":["Single, specific mechanical component targeted (blade retaining rings)","Only two compliance actions required (inspection and replacement)","Clear, fixed deadlines with simple time-in-service calculations","Minimal cross-referencing (only references manufacturer service bulletins and one FAA directive)","No nested exceptions or conditional logic","Short document (approximately 200 words)","Only two defined part numbers (P/N 785540 and P/N 794345)"],"plain_english_summary":"Safety directive orders operators of Dash 8 and ATR 42 aircraft with Hamilton Standard 14SF‑5/14SF‑7 propellers to inspect plastic Rynite blade‑retaining rings for cracks and to replace any cracked rings before flight. It mandates permanent replacement of all Rynite rings with aluminium units by 31 July 1989, eliminating the need for recurring inspections once fitted.\n\nThis affects airlines and maintenance crews because ring failure can cause severe vibration and catastrophic propeller‑retention damage, so the directive enforces immediate and terminating corrective action."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The amendment adds a terminating action requiring replacement of plastic Rynite retaining rings (P/N 785540) with aluminium rings (P/N 794345) rather than relying solely on recurring inspections. The text states: 'This Amendment is raised to introduce terminating action' and sets replacement before 31 July 1989 (Requirement 2; Compliance 2). Applicability to Model 14SF-5 and 14SF-7 propellers remains stated (Applicability)."},"complexity_factors":["Technical specificity: exact propeller models and part numbers (Applicability; Requirement).","Two-stage compliance: recurring inspections plus a mandatory full replacement as terminating action (Requirement 1 & 2; Compliance 1 & 2).","External references: mandatory compliance relies on Hamilton Standard Alert Service Bulletin/SB (ASB 14SF-61-A21 Rev 2; SB 14SF-61-17 Rev 1) and cross-references FAA AD (Requirement; Note).","Safety-critical immediate action: cracked rings must be removed before further flight, producing immediate grounding risk if defects found (Requirement 1; Background).","Time-sensitive scheduling: fixed inspection intervals (50h then 200h) and a fixed replacement deadline (prior to 31 July 1989) constrain maintenance planning (Compliance)."],"plain_english_summary":"Requires operators of Hamilton Standard Model 14SF‑5 and 14SF‑7 propellers (for example on De Havilland Dash 8 and ATR 42 aircraft) to inspect plastic “Rynite” blade retaining rings for cracks and to remove cracked halves before further flight. It also mandates replacing all plastic rings (P/N 785540) with aluminium rings (P/N 794345) as a terminating action. Inspections are due within 50 hours and then every 200 hours; replacement must occur before 31 July 1989. Operators bear inspection, parts and downtime costs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phs-11-amdt-1-blade-retaining-rings","history":"/api/acts/ad-phs-11-amdt-1-blade-retaining-rings/history","analysis":"/api/acts/ad-phs-11-amdt-1-blade-retaining-rings/analysis","conflicts":"/api/acts/ad-phs-11-amdt-1-blade-retaining-rings/conflicts","importantCases":"/api/acts/ad-phs-11-amdt-1-blade-retaining-rings/important-cases","documents":"/api/acts/ad-phs-11-amdt-1-blade-retaining-rings/documents"}}