{"id":"F2006B03128","name":"AD/B747/23 - Outboard Engine Strut Diagonal Brace Forward Clevis Root - Inspection and Modification","slug":"ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42500,"registerId":"commonwealth-F2006B03128-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/23 - Outboard Engine Strut Diagonal Brace Forward Clevis Root - Inspection and Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Boeing 747 Series Aeroplanes\n\n \n\n# AD/B747/23 Outboard Engine Strut Diagonal Brace Forward\n\nClevis Root - Inspection and Modification\n\nApplicability: All model 747 equipped with CF6, JT9D-3 or JT9D-7 engines. Document: 1. FAA AD 80-08-02, Amdt. 39-3738; or\n\n2. Boeing SB No. 747-54-2070.\n\n \n\nCompliance: As per requirement document No. 1.\n\n# 7/80\n\n \n\nBackground: An overseas operator has detected transverse cracks in clevis root of brace. Defect is attributed to local thickness being less than specified.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific structural defect in a defined aircraft fleet. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (under 200 words)","Only 3 defined applicability criteria (aircraft model and engine types)","Single compliance requirement referencing external documents","No nested conditions, exceptions, or procedural subsections","Straightforward technical background with single causal explanation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nRequires owners and operators of **Boeing 747 aircraft** fitted with specific engines (CF6, JT9D-3, or JT9D-7) to inspect and modify a particular structural part — the \"outboard engine strut diagonal brace forward clevis root.\" This is a metal fitting where a support brace connects to the engine mounting structure.\n\n**Why it matters:**\nAn overseas airline found **cracks** in this part. The cracks occurred because the metal was thinner than it should have been at the manufacturing stage. If left unchecked, this structural weakness could lead to engine support failure — a serious safety risk.\n\n**Who must comply:**\nAnyone operating the affected Boeing 747 models in Australia must follow the inspection and modification instructions set out in the referenced FAA (US aviation authority) directive or Boeing's service bulletin.\n\n**Key point:** This is a **mandatory compliance** document — not optional. Aircraft cannot legally fly without completing these safety actions."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive, as supplied, applies to all Model 747 aircraft fitted with CF6, JT9D-3 or JT9D-7 engines and directs compliance with the listed FAA AD or Boeing service bulletin. The text indicates the action addresses transverse cracks found in the clevis root attributed to local thickness shortfall and contains no language expanding or narrowing scope beyond those aircraft and the referenced documents. There is no indication in the supplied text that the applicability or subject matter was altered from the instrument’s stated purpose (Applicability; Document; Background)."},"complexity_factors":["Cross-reference to external technical documents (FAA AD 80-08-02 and Boeing SB 747-54-2070) rather than containing full inspection/modification procedures in the text (Document; Compliance).","Applicability limited to Model 747 aircraft with specific engine types, requiring operators to self-identify affected fleet members (Applicability).","The directive text specifies compliance only by reference (\"As per requirement document No. 1\"), introducing a dependency on locating and interpreting the referenced document (Compliance).","Lack of procedural detail in this text — inspection intervals, acceptance criteria and exact modification steps are not included here and must be obtained from the referenced documents (Document; Compliance).","Potential operational complexity from arranging parts, labour and aircraft downtime if modification is required, which the directive does not quantify (Compliance; Background)."],"plain_english_summary":"Operators of Model 747s fitted with CF6, JT9D-3 or JT9D-7 engines must inspect—and, if required, modify—the forward clevis root of the outboard engine strut diagonal brace to detect and correct transverse cracking found overseas.  \n\nCompliance must follow the referenced technical authority (FAA AD 80-08-02 or Boeing SB 747-54-2070); operators bear inspection/modification costs and schedule impact."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification","history":"/api/acts/ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification/history","analysis":"/api/acts/ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification/analysis","conflicts":"/api/acts/ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification/important-cases","documents":"/api/acts/ad-b747-23-outboard-engine-strut-diagonal-brace-forward-clevis-root-inspection-and-modification/documents"}}