{"id":"F2006B09721","name":"AD/F27/154 - Engine Mount, Brace Struts and Fittings","slug":"ad-f27-154-engine-mount-brace-struts-and-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115903,"registerId":"commonwealth-F2006B09721-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.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.\n\nFokker F27 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/F27/154 Engine Mount, Brace Struts an","sectionType":"part","heading":"AD/F27/154 Engine Mount, Brace Struts and Fittings 9/2002","content":"# AD/F27/154 Engine Mount, Brace Struts and Fittings 9/2002\n\nApplicability: Model F27 MK. 100 through Mk.700 aircraft, all serial numbers, if modified in accordance with one or more of the following service bulletins: F27/71-29, F27/71- 31, F27/71-41, F27/71-42, and F27/54-32; and all aircraft that operate with a standard flap setting for landing of 26.5 degrees.\n\nRequirement: 1. Inspect the engine mounting frame, brace struts and attachment fittings for part number identification and to establish compliance with the additional requirements, as applicable, in accordance with the Accomplishment Instructions of Fokker Service Bulletin F27/54-53, dated 15 February 2002.\n\n2. Replace any engine mounting frames, brace struts and attachment fittings not having the correct part number with the correct parts in accordance with the Accomplishment Instructions of Fokker Service Bulletin F27/54-53.\n\nNote: Netherlands CAA AD 2002-067 refers.\n\nCompliance: 1. Before 1 January 2003.\n\n2 Before 1 July 2004.\n\nThis Airworthiness Directive becomes effective on 5 September 2002.\n\nBackground: Over the years, several modifications have allowed the introduction of higher rated and/or heavier engines, maximum landing weights above 40,000 lbs (18,144 kg) and standard flap settings of 26.5 degrees for landing on certain F27 models. These changes have resulted in increased loads on the engine mounts. The possibility exists that during these upgrades, incorrect engine mounts, brace struts and/or attachment fittings were re- installed.\n\n![Signature of David Villiers, Delegate of the Civil Aviation Safety Authority.](image.002.jpeg)  \n\nDavid Alan Villiers\n\n![](image.001.png)  \nDelegate of the Civil Aviation Safety Authority 24 July 2002\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 14 August 2002.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD targets aircraft with specific modifications or a specified flap setting to address potentially incorrect engine-mount components; the text is consistent with that stated safety purpose and does not indicate an expansion or narrowing of scope beyond that intent."},"complexity_factors":["Applicability is conditional — applies only to F27 Mk.100–Mk.700 aircraft modified per listed service bulletins or operated with 26.5° landing flaps (Applicability).","Actions are limited: inspect for part numbers and replace incorrect parts (Requirement 1–2).","Compliance uses two separate deadlines: inspection by 1 Jan 2003 and replacement by 1 Jul 2004 (Compliance 1–2).","Technical work is outsourced to manufacturer guidance — procedures are those in Fokker Service Bulletin F27/54-53 (Requirement).","Operational cost and logistics risk from sourcing correct parts and grounding time while replacements are made (Requirement 2).","Regulatory basis and enforcement flow from CAR 1998 subreg 39.1(1) via the CASA delegate (preamble/signature).","Reference to Netherlands CAA AD 2002-067 increases cross-jurisdictional alignment but requires operators to track foreign ADs (Note)."],"plain_english_summary":"This Airworthiness Directive requires operators of Fokker F27 Mk.100–Mk.700 aeroplanes (if modified by the listed service bulletins or operated with a 26.5° landing flap) to inspect engine mounting frames, brace struts and attachment fittings for correct part numbers and to replace any incorrect parts following Fokker Service Bulletin F27/54-53. It imposes two fixed compliance deadlines for inspection and for replacement.\n\nMechanically, it forces inspection and parts replacement; operators pay for the work and parts, CASA (the delegate) requires compliance, and the technical procedure depends on the manufacturer’s service instructions."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope: addressing a specific unsafe condition (potential incorrect engine mount parts) in a specific aircraft type (Fokker F27 series with particular modifications). The scope has not expanded beyond this targeted safety issue."},"complexity_factors":["Single, clearly defined applicability section with specific model numbers and service bulletins","Two straightforward requirements: inspect and replace if necessary","Two distinct compliance dates with clear deadlines","Minimal cross-referencing (only to one Fokker Service Bulletin and one Netherlands CAA AD)","No nested exceptions or conditional logic beyond the initial applicability criteria","Short document (approximately 300 words) with simple sentence structure","Only one defined term implicitly used ('Accomplishment Instructions' from the referenced service bulletin)"],"plain_english_summary":"This Airworthiness Directive orders owners/operators and maintenance organisations of certain Fokker F27 Mark 100–700 aircraft (those modified by specified engine upgrades or using 26.5° landing flaps) to inspect engine mounts, brace struts and fittings for correct part numbers and replace any incorrect parts. It responds to higher loads from more powerful engines/higher landing weights that could cause engine separation in flight. Inspections by 1 Jan 2003; replacements by 1 Jul 2004."},"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-f27-154-engine-mount-brace-struts-and-fittings","history":"/api/acts/ad-f27-154-engine-mount-brace-struts-and-fittings/history","analysis":"/api/acts/ad-f27-154-engine-mount-brace-struts-and-fittings/analysis","conflicts":"/api/acts/ad-f27-154-engine-mount-brace-struts-and-fittings/conflicts","importantCases":"/api/acts/ad-f27-154-engine-mount-brace-struts-and-fittings/important-cases","documents":"/api/acts/ad-f27-154-engine-mount-brace-struts-and-fittings/documents"}}