{"id":"F2006B08477","name":"AD/CF6/34 - Fan Reverser Centre Drive Unit","slug":"ad-cf6-34-fan-reverser-centre-drive-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51149,"registerId":"commonwealth-F2006B08477-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CF6/34 - Fan Reverser Centre Drive Unit","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nGeneral Electric Turbine Engines \\- CF6 Series\n\nAD/CF6/34 Fan Reverser Centre Drive Unit 11/95\n\nApplicability: CF6-80C2 series engine installations.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 95-10-11 Amdt 39- 9228.\n\nNote: Martin Marietta CF6-80C2 SB No. 78-1002 Revision 1 also refers.\n\nCompliance: As specified in the Requirement Document with a revised effective date of 12 October 1995.\n\nBackground: The FAA received a report that during routine maintenance a centre drive unit (CDU) was not able to hold the fan reverser translating cowl when it was manually driven to its stow position. Investigation highlighted a CDU brake shaft manufacturing error. This situation could result in the possible movement of the fan reverser translating cowl towards the deploy position in flight.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific manufacturing defect in a specific engine series. It has not expanded beyond its original purpose of mandating inspection/replacement of faulty centre drive units."},"complexity_factors":["Single, specific mechanical component addressed (centre drive unit brake shaft)","No defined terms section — relies entirely on external FAA document for technical requirements","No conditional logic or nested exceptions within the directive itself","Cross-reference to only one external document (FAA AD 95-10-11) and one service bulletin","Extremely short — approximately 150 words total","Clear, single compliance deadline (12 October 1995)"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft engines.\n\n**What it does:**\nOrders airlines and aircraft operators to inspect and fix a specific mechanical problem in **General Electric CF6-80C2 jet engines** (commonly used on Boeing 747s and Airbus A300/A310 aircraft).\n\n**The safety problem:**\nA manufacturing defect in the **centre drive unit (CDU)** — a component that helps lock the engine's thrust reverser in place. The faulty brake shaft could allow the thrust reverser to move toward the \"deploy\" position during flight. If a thrust reverser deployed in flight, it could cause catastrophic loss of control.\n\n**Who must act:**\nAnyone operating aircraft with CF6-80C2 engines must follow the technical instructions from the US Federal Aviation Administration (FAA AD 95-10-11).\n\n**Why it matters:**\nThrust reversers are designed to slow aircraft after landing. If one accidentally deploys mid-flight, it can create asymmetric thrust or aerodynamic disruption. This directive prevents a potential accident by forcing operators to check and replace faulty components before they fail."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive does not broaden or narrow the set of affected engines or the substantive actions required; it adopts the existing FAA AD requirements for CF6-80C2 engines and sets a revised effective date of 12 October 1995. The instrument therefore adjusts timing but does not change the scope of who is covered or what corrective actions must be taken. (Applicability; Requirement; Compliance)"},"complexity_factors":["Cross-reference to external technical document (FAA AD 95-10-11) — reliance on external material increases practical complexity","Reference to manufacturer service bulletin (Martin Marietta SB No. 78-1002 Rev 1) as related technical guidance","Technical, safety-critical subject matter requiring qualified maintenance personnel and possible parts replacement","Narrow applicability (only CF6-80C2 engine installations) which simplifies legal scope but concentrates technical work on affected operators","Administrative element: revised effective date (requires operators to note timing for compliance)"],"plain_english_summary":"This instrument requires owners/operators of aircraft with General Electric CF6-80C2 engines to comply with FAA Airworthiness Directive 95-10-11 (Amdt 39-9228), revised effective 12 October 1995, after a CDU brake-shaft manufacturing error could let the translating cowl move toward deploy in flight. It affects operators of CF6-80C2 installations, directs them to the FAA AD (and related Martin Marietta service bulletin), and imposes inspection/repair costs and downtime on operators or their maintenance/insurer arrangements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-34-fan-reverser-centre-drive-unit","history":"/api/acts/ad-cf6-34-fan-reverser-centre-drive-unit/history","analysis":"/api/acts/ad-cf6-34-fan-reverser-centre-drive-unit/analysis","conflicts":"/api/acts/ad-cf6-34-fan-reverser-centre-drive-unit/conflicts","importantCases":"/api/acts/ad-cf6-34-fan-reverser-centre-drive-unit/important-cases","documents":"/api/acts/ad-cf6-34-fan-reverser-centre-drive-unit/documents"}}