{"id":"F2005L00232","name":"AD/BR700/5 - High Pressure Compressor Front Drum","slug":"ad-br700-5-high-pressure-compressor-front-drum","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":33788,"registerId":"commonwealth-F2005L00232-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rolls Royce Germany Turbine Engines - BR","sectionType":"division","heading":"Rolls Royce Germany Turbine Engines - BR700 Series","content":"### Rolls Royce Germany Turbine Engines - BR700 Series\n\n| AD/BR700/5 | High Pressure Compressor Front Drum | 3/2005 |\n| ---------- | ----------------------------------- | ------ |\n\n| Applicability: | Rolls Royce Model BR700-710 Engine Serial Number 11141.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Remove from service and discard High Pressure Compressor (HPC) front drum Part Number (P/N) BRR20378 Serial Number (S/N) 119.2. Do not install the HPC drum removed per requirement 1.Note 1: The life limit of the affected HPC front drum, P/N BRR20378, S/N 119 is lower than the life limit for all other HPC front drums P/N BRR20378 as declared in the Time Limits Manual, Chapter 05-10-01. Rolls Royce Service Bulletin SB-BR700-72-900347 dated 03 November 2004 refers.Note 2: German LBA Airworthiness Directive D-2004-494 approved under EASA reference 2004-12661 dated 31 December 2004 refers.           |\n| Compliance:    | 1. On or before HPC front drum P/N BRR20378 S/N 119 reaching a total of 7800 flight cycles since new.2. After the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n|                | This Airworthiness Directive becomes effective on 17 March 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |\n| Background:    | During rework, HPC front drum P/N BRR20378, S/N 119 was inadvertently heat treated after cold expansion of the stage 6 boltholes. It therefore lost some of the protective compressive stresses from the cold expansion. As a result of this, it is necessary to reduce the life of the affected HPC front drum, to 7800 flight cycles instead of the previously declared 10000 flight cycles. The affected HP compressor front drum is currently installed to the engine with S/N 11141.This AD addresses the identified unsafe condition associated with HPC front drum cracking and resultant uncontained engine failure. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n4 February 2005","sortOrder":0},{"sectionNumber":"AD/BR700/5","sectionType":"part","heading":"AD/BR700/5","content":"## AD/BR700/5","sortOrder":1},{"sectionNumber":"High Pressure Compressor Front Drum","sectionType":"part","heading":"High Pressure Compressor Front Drum","content":"## High Pressure Compressor Front Drum","sortOrder":2},{"sectionNumber":"3/2005","sectionType":"part","heading":"3/2005","content":"## 3/2005","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":true,"description":"The directive narrows and reduces the permitted life for a specific HPC front drum: P/N BRR20378, S/N 119 is limited to 7,800 flight cycles instead of the previously declared 10,000 (Requirement; Background). It mandates removal and discard of that drum on the engine with S/N 11141 before 7,800 cycles and prohibits reinstalling it (Requirement; Applicability)."},"complexity_factors":["Applicability limited to a single engine serial number and one drum serial number (Applicability) — narrows affected population and simplifies identification.","Single, non‑repairable required action: remove from service and discard the specified part; do not reinstall (Requirement) — low operational ambiguity.","Clear numeric life‑limit change from 10,000 to 7,800 flight cycles (Requirement/Background) — straightforward compliance metric.","Technical root cause is specific (inadvertent heat treatment after cold expansion reducing compressive stresses) — technical but focused (Background).","Cross‑references to a manufacturer service bulletin and a German/EASA airworthiness directive (Notes) — adds administrative cross‑checks for operators and maintainers.","Fixed compliance timing and effective date (Compliance) — reduces discretionary implementation choices.","Stated safety consequence (HPC cracking and uncontained engine failure) increases urgency but does not add procedural complexity (Background)."],"plain_english_summary":"This directive requires removal and destruction of one specific High Pressure Compressor (HPC) front drum (P/N BRR20378, S/N 119) fitted to a Rolls‑Royce BR700‑710 engine (engine S/N 11141) and forbids reinstalling it. It shortens that drum’s allowable life to 7,800 flight cycles (previously 10,000) because an inadvertent heat treatment removed protective compressive stresses, creating a cracking and uncontained‑failure risk; compliance is required before 7,800 cycles (effective 17 March 2005)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope. It was issued to address a specific manufacturing defect in a single part on a single engine, and remains precisely targeted at that unsafe condition without expansion to broader engine types or parts."},"complexity_factors":["Single, specific applicability: only one engine serial number (11141) and one part serial number (119)","Clear, unambiguous requirements: remove and discard one specific part","Simple compliance condition: time-based (7,800 flight cycles) with a backstop date","No cross-references to other legislation beyond informational references to foreign airworthiness directives and manufacturer service bulletins","No defined terms section, no conditional logic, no exceptions or exemptions","Extremely short document (approximately 300 words of substantive content)"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's aviation regulator (CASA). It applies to **one specific aircraft engine**: a Rolls-Royce BR700-710 engine with serial number 11141.\n\n**What the problem is:**\nA particular part inside this engine — the High Pressure Compressor (HPC) front drum, part number BRR20378, serial number 119 — was accidentally heat-treated during repairs. This damaged the protective stress properties of the metal, making it more likely to crack. If the drum cracks, the engine could fail catastrophically (an \"uncontained engine failure\" where parts could fly out).\n\n**What must be done:**\n- **Remove and scrap** the affected HPC front drum before it reaches **7,800 flight cycles** (takeoff-landing cycles)\n- **Never reinstall** this specific part\n- The normal life limit for this part type is 10,000 cycles, but this specific drum must be retired **2,200 cycles earlier** due to the manufacturing error\n\n**Why it matters:**\nThis prevents a potentially deadly engine failure. The directive became effective on **17 March 2005**."}},"importantCases":[],"_links":{"self":"/api/acts/ad-br700-5-high-pressure-compressor-front-drum","history":"/api/acts/ad-br700-5-high-pressure-compressor-front-drum/history","analysis":"/api/acts/ad-br700-5-high-pressure-compressor-front-drum/analysis","conflicts":"/api/acts/ad-br700-5-high-pressure-compressor-front-drum/conflicts","importantCases":"/api/acts/ad-br700-5-high-pressure-compressor-front-drum/important-cases","documents":"/api/acts/ad-br700-5-high-pressure-compressor-front-drum/documents"}}