{"id":"F2006B06465","name":"AD/R44/15 - Sprag Clutch","slug":"ad-r44-15-sprag-clutch","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":47949,"registerId":"commonwealth-F2006B06465-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/R44/15 Sprag Clutch 7/2000","sectionType":"part","heading":"AD/R44/15 Sprag Clutch 7/2000","content":"# AD/R44/15 Sprag Clutch 7/2000\n\nApplicability: Model R44 helicopters serial number 0001 through 0541 inclusive, 0543, 0550, 0556\n\nand 0565.\n\nRequirement: 1. Examine sprag clutch for S/N applicability. Replace any sprag clutch with S/N 0003 through 0505 inclusive in accordance with the procedures detailed in Robinson R44 Service Bulletin SB-32 Part B paragraph 1 to 5 inclusive.\n\nNote 1: Robinson R44 SB-36 expands affected clutch S/N range to include S/Nos 0453 through 0505.\n\n2. Remove the pink page Special Pilot Caution covering autorotation with a possible defective sprag clutch from the Normal Procedures Section of the R44 flight manual.\n\nNote 2: FAA AD 2000-08-04 Amendment 39-11690 and FAA AD 99-07-18 refers\n\nCompliance: 1. Unless previously carried out, within 30 calendar days or 50 hours time in service, whichever occurs first, from the effective date of this Directive.\n\n2. Upon accomplishment of Requirement 1.\n\nThis Airworthiness Directive becomes effective on 13 July 2000.\n\n![](image.003.png)Background: Robinson Helicopter Co has advised that several sprag clutches, one from an accident aircraft, have been returned with cracked sprag ends. To prevent sprag clutch failure with possible loss of main rotor RPM this Directive mandates replacement of the sprag clutch assembly.\n\n![](image.004.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 23 May 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 14 June 2000.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: addressing a specific manufacturing defect in a specific helicopter model's sprag clutch. The document references an expanded serial number range via service bulletin note, but this represents clarification of affected units rather than scope creep beyond the original safety purpose."},"complexity_factors":["Very short document (approximately 300 words)","Only 3 defined serial number ranges in applicability section","Single primary requirement with one straightforward action (replace part)","Simple compliance timeline (30 days or 50 hours)","Minimal cross-referencing (only to Robinson Service Bulletin SB-32 and SB-36, plus FAA ADs in a note)","No nested exceptions or conditional logic — requirements apply uniformly to all affected aircraft","Clear, unambiguous language throughout"],"plain_english_summary":"The Civil Aviation Safety Authority has issued a mandatory Airworthiness Directive requiring owners of certain Robinson R44 helicopters (specific early serial numbers) to replace a faulty sprag clutch that can crack and allow loss of main-rotor speed. \n\nThis urgent safety fix prevents catastrophic autorotation failure; affected operators must follow Robinson’s repair instructions promptly to restore safe operation."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The directive as issued targets replacement of sprag clutches with specified part serial numbers fitted to a defined subset of R44 airframes. The effective scope of affected parts was expanded by the manufacturer's subsequent service bulletin (Robinson SB-36), which broadened the clutch S/N range to include additional numbers (Note 1). That expansion increases the number of aircraft/owners required to comply relative to the AD's initial S/N range and therefore represents a concrete widening of the compliance universe compared with the AD's original narrow part list."},"complexity_factors":["Short document: two basic mandatory actions (inspect/replace part; remove flight manual page).","Single, simple compliance deadline (within 30 calendar days or 50 hours TIS, whichever first).","Limited applicability defined by aircraft serial numbers (one contiguous block plus a few specific serials).","Affected part range specified by clutch serial numbers (initially S/N 0003–0505, with SB-36 expanding range to include 0453–0505).","Cross-references to external documents: Robinson R44 Service Bulletin SB-32 Part B (procedures), SB-36 (S/N expansion), and FAA ADs — adds modest external dependency.","Two notes that modify or clarify the S/N applicability (introducing a small conditional change).","No nested exceptions, few defined terms, and no layered conditional logic beyond the compliance timing rule."],"plain_english_summary":"**What this directive does (mechanically)\n\n- Requires owners/operators of certain Robinson R44 helicopters to examine and, where necessary, replace the sprag clutch assembly (the one-way clutch in the rotor drive) if the clutch has a serial number (S/N) in the affected range. (See \"Requirement 1\".)\n- After replacing an affected clutch, the operator must remove the pink \"Special Pilot Caution\" page about autorotation from the Normal Procedures section of the R44 flight manual. (See \"Requirement 2\".)\n- Compliance must be completed within 30 calendar days or 50 hours time-in-service, whichever comes first, from the directive's effective date.\n\n**Which aircraft are affected\n\n- The AD applies only to Robinson R44 helicopters with airframe serial numbers listed in the Applicability section: serials 0001 through 0541 inclusive, and specifically 0543, 0550, 0556 and 0565.\n- The requirement to replace is triggered only if the sprag clutch fitted to those aircraft has a clutch serial number in the affected range (initially S/N 0003 through 0505; Robinson later expanded the affected clutch S/N range to include 0453 through 0505 via Service Bulletin SB-36).\n\n**Why the rule exists (official reason)\n\n- The manufacturer reported returned sprag clutches with cracked sprag ends (including one from an accident aircraft). A cracked sprag could cause sprag clutch failure and a possible loss of main rotor RPM, especially during autorotation. The AD compels replacement of suspect clutches to correct that unsafe condition.\n\n**Who decides and who pays\n\n- The Civil Aviation Safety Authority (CASA) delegate issued the AD and sets the compliance deadline. The technical procedure to be followed for replacement is specified by the manufacturer in Robinson R44 Service Bulletin SB-32 Part B (paragraphs 1–5).\n- Costs for parts, labour and aircraft downtime fall on the aircraft owner/operator. Maintenance must be carried out by appropriately authorised maintenance personnel.\n\n**How it affects operators and the market\n\n- Immediate compliance imposes short-term costs: the replacement part price, labour, and aircraft downtime (which can be significant for small operators). Those costs are concentrated on owners of the affected R44 serial-numbered helicopters that have the suspect sprag clutches.\n- The AD reduces operational choice for affected owners until replacement is performed (they cannot legally continue to operate with a known-affected clutch without contravening the AD). There is a procedural dependence on the manufacturer’s service bulletin for the correct replacement method.\n- The directive may create temporary demand pressure for replacement parts and qualified maintenance slots; this can raise costs or delay compliance if parts or labour are scarce.\n\n**Implementation and compliance risks\n\n- The AD cross-references the manufacturer’s service bulletin (SB-32 Part B) for the replacement procedure; incorrect or incomplete adherence to that bulletin risks ineffective remediation.\n- Inspecting clutch serial numbers requires physical access; operators must verify part S/Ns to determine applicability, which can create inspection workload.\n- Removing the pink caution page is conditional on completing the replacement; operators must ensure flight manuals are updated to remain compliant.\n\n**Notes and cross-references\n\n- The AD refers to FAA ADs (FAA AD 2000-08-04 and FAA AD 99-07-18) and Robinson service bulletins (SB-32 and SB-36). The Robinson SB-36 note expands the range of affected clutch S/Ns (see Requirement 1, Note 1).\n\n**Net effect (mechanics, not judgment)\n\n- The directive mandates a part-level inspection and replacement on a targeted subset of R44 helicopters, with a short compliance window, to remove a specific mechanical failure risk. Owners/operators bear the cost and disruption; CASA and the manufacturer specify what must be done and how.\n\n(References: Applicability; Requirement 1 & 2; Compliance; Background.)"},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-r44-15-sprag-clutch","history":"/api/acts/ad-r44-15-sprag-clutch/history","analysis":"/api/acts/ad-r44-15-sprag-clutch/analysis","conflicts":"/api/acts/ad-r44-15-sprag-clutch/conflicts","importantCases":"/api/acts/ad-r44-15-sprag-clutch/important-cases","documents":"/api/acts/ad-r44-15-sprag-clutch/documents"}}