{"id":"F2006B08374","name":"AD/CESSNA 400/90 Amdt 2 - Engine Mount Beams","slug":"ad-cessna-400-90-amdt-2-engine-mount-beams","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115795,"registerId":"commonwealth-F2006B08374-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/90 Amdt 2 - Engine Mount Beams","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 400 Series Aeroplanes\n\nAD/CESSNA 400/90\n\nAmdt 2\n\n  \nEngine Mount Beams 2/89\n\nApplicability: Model 404 with S/Nos 404-0001 to 404-0859. Requirement: Action in accordance with:\n\n    Cessna Service Bulletin MEB 86-7 and\n\n    2. Cessna Service Bulletin MEB 88-2; or\n\nan alternative scheme approved by the Authority. East-West Airlines Drawing C-71- 20-2137 is an approved alternative to SB MEB 88-2 for modification of the forward area of the engine mount beam.\n\nNote: Aircraft in compliance with the original issue of this Directive may require additional work in accordance with the Requirement Documents.\n\nCompliance: Inspections: In accordance with the Requirement Documents.\n\nModifications: Unless already accomplished; before further flight if cracks are detected during inspections.\n\nNote: Embodiment of modifications, which constitute terminating action for this Directive, may be accomplished at any time prior to detection of cracks.\n\nBackground: The manufacturer reports that cracking may occur in the region of the fwd and aft engine mount attachment holes on the engine mount beam. Amendment 1 to this Directive added the requirements of SB MEB 88-2, which details inspection and modification of the forward area of the engine mount beam. Amendment 1 also made it mandatory to modify the aft area in accordance with SB MEB 86-7. Amendment 2 recognises East-West Airlines Drawing C-71-20-2137 as an alternative scheme for modification of the forward area.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive has remained tightly focused on its original purpose: addressing cracking in Cessna 404 engine mount beams. The amendments (1 and 2) have added specificity and flexibility (additional service bulletin requirements and an approved alternative modification scheme) without expanding beyond the core safety issue. The scope has not drifted from the original intent."},"complexity_factors":["Short, single-purpose directive (approximately 250 words)","Only 4 defined elements: specific aircraft model, serial number range, two service bulletins, and one alternative engineering drawing","Simple conditional logic: 'if cracks found, then modify before flight'","No nested exceptions or cross-references to other legislation","Clear compliance timeline with only two triggers (inspection schedule vs crack detection)","Background section provides plain-English explanation of amendments"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspections and, if necessary, repairs to the engine mount beams on Cessna 404 aircraft (S/N 0001–0859) to detect and fix cracks around the forward and aft attachment holes. Owners/operators must follow Cessna service bulletins (with a CASA‑approved East‑West Airlines drawing as an alternative for the forward area); aircraft with cracks are grounded until repaired.\n\nThe rule prevents catastrophic engine separation, may require additional work even after prior compliance, and allows permanent modification at any time."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The Directive has been expanded since the original issue: Amendment 1 added mandatory modification and inspection requirements tied to SB MEB 88-2 and made the aft-area modification mandatory under SB MEB 86-7; Amendment 2 recognises East-West Airlines Drawing C-71-20-2137 as an approved alternative for the forward-area modification (Background)."},"complexity_factors":["Narrow applicability to a single model and serial range (Applicability).","Normative dependence on two separate service bulletins plus an approved alternative drawing (Requirement).","Two distinct action types: recurring inspections and conditional immediate modification if cracks are found (Compliance).","Regulatory discretion to accept alternative schemes, requiring Authority approval (Requirement/Background).","Note that prior compliance with an earlier issue may still require additional work (Note/Background)."],"plain_english_summary":"Mandates inspections and, if cracks are found, modification of engine mount beams on Cessna Model 404 (S/N 404-0001 to 404-0859) in accordance with Cessna Service Bulletins MEB 86‑7 and MEB 88‑2, or an Authority‑approved alternative (East‑West Airlines Drawing C-71-20-2137 is approved for the forward area). Owners/operators must perform inspections per the Requirement/Compliance clauses and complete modifications before further flight when cracks are detected; the Civil Aviation Safety Authority approves alternative schemes and the modification can terminate the Directive."},"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-cessna-400-90-amdt-2-engine-mount-beams","history":"/api/acts/ad-cessna-400-90-amdt-2-engine-mount-beams/history","analysis":"/api/acts/ad-cessna-400-90-amdt-2-engine-mount-beams/analysis","conflicts":"/api/acts/ad-cessna-400-90-amdt-2-engine-mount-beams/conflicts","importantCases":"/api/acts/ad-cessna-400-90-amdt-2-engine-mount-beams/important-cases","documents":"/api/acts/ad-cessna-400-90-amdt-2-engine-mount-beams/documents"}}