{"id":"F2005L00623","name":"AD/RB211/25 Amdt 1 - Cold Stream Nozzle","slug":"ad-rb211-25-amdt-1-cold-stream-nozzle","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":112901,"registerId":"commonwealth-F2005L00623-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rolls Royce Turbine Engines - RB211 Seri","sectionType":"division","heading":"Rolls Royce Turbine Engines - RB211 Series","content":"### Rolls Royce Turbine Engines - RB211 Series\n\n| AD/RB211/25 Amdt 1 | Cold Stream Nozzle | 4/2005 |\n| ------------------ | ------------------ | ------ |\n\n| Applicability: | Rolls Royce RB211-524D4-B-19, -524D4-B-39, -524D4-19, -524D4X-B-19 and -524D4X-19 engines fitted with the lightweight standard of thrust reverser, not incorporating Rolls-Royce Service Bulletin RB211 78-D167.Note 1: After incorporation of Rolls-Royce Service Bulletin RB211 78-D167, the requirement for this on-wing Cold Nozzle re-inspection is deleted.                                                                                                                 |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Inspect the affected area of the cold stream nozzle for evidence of cracking in accordance with Rolls Royce Service Bulletin RB.211-78-C955, Issue 2 dated 31 January 2000.Note 2: UK CAA AD 005-01-2000 refers.                                                                                                                                                                                                                                                                  |\n| Compliance:    | Remains unchanged as: Unless previously accomplished, within 60 days time in service or 100 flight cycles, whichever occurs first, from the effective date of the original issue of this directive. Thereafter, reinspect at intervals not exceeding 1,400 cycles time in service.                                                                                                                                                                                                |\n|                | This Amendment becomes effective on 14 April 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| Background:    | This Directive was raised to mandate inspection, using a borescope, of the cold stream nozzle longitudinal flange for evidence of cracking. Revision 2 of the manufacturer’s service bulletin allows for terminating action.This amendment introduces terminating action for those nozzles incorporating Rolls-Royce Service Bulletin RB211 78-D167 with no change to the compliance times.The original issue of this Airworthiness Directive became effective on 10 August 2000. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n2 March 2005","sortOrder":0},{"sectionNumber":"AD/RB211/25 Amdt 1","sectionType":"part","heading":"AD/RB211/25 Amdt 1","content":"## AD/RB211/25 Amdt 1","sortOrder":1},{"sectionNumber":"Cold Stream Nozzle","sectionType":"part","heading":"Cold Stream Nozzle","content":"## Cold Stream Nozzle","sortOrder":2},{"sectionNumber":"4/2005","sectionType":"part","heading":"4/2005","content":"## 4/2005","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment adds a terminating action not present in the original directive: if a nozzle has been modified in accordance with Rolls‑Royce Service Bulletin RB211 78‑D167, the on‑wing cold stream nozzle re‑inspection requirement is deleted. Compliance intervals remain unchanged. (See Applicability and Background.)"},"complexity_factors":["Applicability: narrow engine-model list and conditional exclusion after incorporation of Rolls‑Royce Service Bulletin RB211 78‑D167 (Applicability).","Requirement: specifies a technical inspection method (borescope) and cites Rolls Royce Service Bulletin RB.211‑78‑C955, Issue 2 (Requirement).","Compliance timing: initial window (60 days or 100 flight cycles) and recurrent interval (1,400 cycles) create scheduling and tracking needs (Compliance).","Terminating action: amendment introduces deletion of the re‑inspection obligation upon incorporation of SB RB211 78‑D167, creating a binary compliance state operators must verify (Background / Applicability).","Cross‑references: relies on multiple external documents and another regulator's AD (UK CAA AD 005‑01‑2000), increasing administrative coordination (Requirement / Background).","Regulatory status and effective date: fixed effective date (14 April 2005) and delegation naming the CSA delegate, which matters for enforcement and recordkeeping (Background / header)."],"plain_english_summary":"This Airworthiness Directive requires operators of certain Rolls‑Royce RB211‑524D4 series engines (with the lightweight thrust reverser and not modified by Rolls‑Royce SB RB211‑78‑D167) to borescope‑inspect the cold stream nozzle flange for cracking at prescribed initial and recurring intervals. It takes effect 14 April 2005.\n\nThe amendment adds a terminating action: if the nozzle has been modified per SB RB211‑78‑D167, the on‑wing re‑inspection requirement is removed. This changes ongoing maintenance workload and scheduling for affected operators."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope precisely. It adds a terminating action (allowing operators to stop recurring inspections by installing a design modification) but does not expand the applicability to new engine types, add new inspection requirements, or broaden the safety concern beyond the original cold stream nozzle cracking issue."},"complexity_factors":["Highly specific applicability limited to 5 exact engine model variants with specific thrust reverser configuration","Conditional logic: requirement applies only if Service Bulletin RB211 78-D167 has NOT been incorporated","Dual compliance triggers (time-based: 60 days; usage-based: 100 flight cycles) with 'whichever occurs first' logic","Ongoing recurring obligation (1,400 cycle intervals) with terminating action condition","Cross-reference to external technical document (Rolls-Royce Service Bulletin RB.211-78-C955, Issue 2)","Cross-reference to UK regulatory instrument (UK CAA AD 005-01-2000)","Nested effective dates: references original effective date (10 August 2000), amendment effective date (14 April 2005), and compliance calculation from original issue"],"plain_english_summary":"This CASA Airworthiness Directive mandates borescope inspections for cracks in the cold stream nozzle of certain Rolls‑Royce RB211‑524 engine variants that have the lightweight thrust reverser and have not had Service Bulletin RB211 78‑D167 installed. Initial and recurring inspection intervals are specified to catch damage that could lead to engine failure.\n\nThe April 2005 amendment lets operators permanently end the recurring inspections by installing the RB211 78‑D167 modification."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rb211-25-amdt-1-cold-stream-nozzle","history":"/api/acts/ad-rb211-25-amdt-1-cold-stream-nozzle/history","analysis":"/api/acts/ad-rb211-25-amdt-1-cold-stream-nozzle/analysis","conflicts":"/api/acts/ad-rb211-25-amdt-1-cold-stream-nozzle/conflicts","importantCases":"/api/acts/ad-rb211-25-amdt-1-cold-stream-nozzle/important-cases","documents":"/api/acts/ad-rb211-25-amdt-1-cold-stream-nozzle/documents"}}