{"id":"F2006B03105","name":"AD/B747/206 - Upper Link Assembly on Number 2 and Number 3 Engine Struts","slug":"ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42477,"registerId":"commonwealth-F2006B03105-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/206 - Upper Link Assembly on Number 2 and Number 3 Engine Struts","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)  \nBoeing 747 Series Aeroplanes\n\nAD/B747/206 Upper Link Assembly on Number 2\n\nand Number 3 Engine Struts\n\n  \n7/99\n\nApplicability: Boeing 747 series aircraft, line positions 1 through 886; equipped with Pratt & Whitney JT9D-3 or -7, or General Electric CF6-45 or -50 engine struts.\n\nRequirement: Action in accordance with the technical requirements of FAA AD 99-08-01 Amdt 39- 11105.\n\nNote: Boeing Alert Service Bulletin 747-54A2187 refers.\n\nCompliance: Initial and repeat inspections as specified in the requirement document with a revised effective date of 15 July 1999.\n\nThis Airworthiness Directive becomes effective on 15 July 1999.\n\nBackground: The FAA received reports of corrosion and cracks located at the four fasteners that attach to the aft end to the upper link assembly on the number 2 and number 3 engine struts.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s scope is consistent with its stated purpose: to detect and address corrosion and cracking at the fasteners of the upper link assembly on the number 2 and number 3 engine struts of the specified Boeing 747 sub-fleet. It limits applicability by line position and engine strut type and adopts the technical inspection and remedy requirements from the referenced FAA AD and Boeing service bulletin; it does not expand beyond those technical and fleet limits described in the instrument (Applicability; Requirement; Note; Background)."},"complexity_factors":["Cross-reference to an external FAA airworthiness directive (FAA AD 99-08-01 Amdt 39-11105) for technical requirements (Requirement).","Reference to a manufacturer service document (Boeing Alert Service Bulletin 747-54A2187) for procedural detail (Note).","Fleet-specific applicability (Boeing 747 line positions 1–886) limited to particular engine strut models, requiring operators to check serial/line status (Applicability).","Recurring (initial and repeat) inspection obligations create an ongoing compliance task and scheduling complexity (Compliance).","The directive mandates action but leaves procedural specifics and corrective measures to the referenced FAA and Boeing documents, increasing dependency on external documents and expertise (Requirement; Note)."],"plain_english_summary":"What this instrument does (mechanically)\n\n- Requires specific inspections of the upper link assembly fasteners on the number 2 and number 3 engine struts of certain Boeing 747 aeroplanes. The inspections must be carried out “in accordance with the technical requirements of FAA AD 99-08-01 Amdt 39-11105.” (Requirement)\n- Sets an effective compliance date of 15 July 1999 and requires both initial and repeat inspections as specified in the referenced FAA airworthiness directive. (Compliance)\n\nWho this affects\n\n- Operators and maintainers of Boeing 747 series aircraft, line positions 1 through 886, that are equipped with Pratt & Whitney JT9D-3 or -7, or General Electric CF6-45 or -50 engine struts. (Applicability)\n- The Civil Aviation Safety Authority (CASA) is the issuing authority for this directive; the technical substance is adopted from the FAA document. (Header; Requirement)\n\nWhy it matters (stated reason and mechanical effect)\n\n- The FAA reported corrosion and cracking at the four fasteners that attach the aft end of the upper link assembly on the number 2 and number 3 engine struts. The inspections are intended to identify and address those corrosion/crack issues before they cause further damage. (Background)\n\nOperational and compliance implications (mechanisms, incentives, costs, and trade-offs)\n\n- Who pays: Aircraft operators and their maintenance providers bear the direct costs of performing the inspections, any follow-up inspections, and any repairs or part replacements identified. (Applicability; Requirement; Compliance)\n- What decisions are required: Operators must schedule and perform the initial and recurring inspections specified by the FAA AD and must follow any corrective actions that the FAA AD or the Boeing service information require. CASA’s directive makes compliance mandatory. (Requirement; Compliance)\n- Compliance burden: The directive mandates initial and repeat inspections (Compliance). Those inspections create a recurring maintenance task that will use labour, materials and maintenance time; they may also require aircraft downtime while work is performed. (Requirement; Compliance)\n- Dependency on external documents: The technical inspection and corrective-action details are contained in the FAA AD referenced and in Boeing Alert Service Bulletin 747-54A2187 which the FAA AD refers to. That creates operational dependence on two external documents for procedure and scope. (Requirement; Note)\n- Incentives and behaviour: Operators are incentivised to perform the inspections and repairs to restore or retain legal airworthiness and to reduce the risk of part failure. The immediate cost is borne by operators; the intended benefit is reduced risk of in-service failure tied to the identified corrosion/cracking. (Background; Requirement)\n- Trade-offs and opportunity costs: Time and money spent on inspections and any required repairs are resources not available for other maintenance or operational activities; operators will weigh these costs against the legal and safety obligation to comply. (Requirement; Compliance)\n- Implementation risks and practical constraints: Effective implementation requires access to the FAA AD and Boeing service bulletin, trained maintenance personnel familiar with the specified inspections, and availability of any replacement parts or repair materials. The directive does not itself set out enforcement mechanisms or penalties beyond making the FAA AD’s technical requirements mandatory under CASA’s authority. (Requirement; Note)\n\nSource references\n\n- Applicability: specifies the affected aircraft and engine strut types. (Applicability)\n- Requirement: mandates action in accordance with FAA AD 99-08-01 Amdt 39-11105. (Requirement)\n- Note: identifies Boeing Alert Service Bulletin 747-54A2187 as a related document. (Note)\n- Compliance: prescribes initial and repeat inspections and the effective date of 15 July 1999. (Compliance)\n- Background: describes reported corrosion and cracking at the four fasteners attaching the aft end of the upper link assembly on the number 2 and number 3 engine struts. (Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with a narrow, specific safety purpose. It has not expanded beyond its original intent of addressing a specific mechanical defect on specific aircraft models."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly used (\"Compliance\" with standard aviation meaning)","No cross-references to other legislation beyond a single reference to a US FAA directive","Simple conditional structure: if your plane matches the description, you must do the inspection","Single requirement with clear effective date","No nested exceptions or complex procedural steps in the directive itself (technical details are outsourced to the referenced FAA document)"],"plain_english_summary":"This is a **safety order for specific Boeing 747 aircraft**. It requires airlines and aircraft operators to inspect and fix a particular mechanical problem on certain Boeing 747 planes.\n\n**What the problem is:**\nThe metal parts that connect the engines to the wings (called \"upper link assemblies\" on engines 2 and 3) have been found to develop **corrosion and cracks** around four specific bolts. This is a serious safety issue because these parts hold the engines in place.\n\n**Which planes are affected:**\n- Boeing 747 series aircraft (production line numbers 1 through 886)\n- Planes with specific Pratt & Whitney or General Electric engines\n\n**What must be done:**\n- Operators must follow the inspection and repair instructions from the US Federal Aviation Administration (FAA AD 99-08-01)\n- They must do initial inspections and then repeat them on a schedule\n- The deadline to start complying is 15 July 1999\n\n**Why it matters:**\nIf these cracked parts aren't found and fixed, an engine could potentially detach from the aircraft in flight. This directive ensures all affected Australian-registered aircraft get checked and repaired before they can fly."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts","history":"/api/acts/ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts/history","analysis":"/api/acts/ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts/analysis","conflicts":"/api/acts/ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts/conflicts","importantCases":"/api/acts/ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts/important-cases","documents":"/api/acts/ad-b747-206-upper-link-assembly-on-number-2-and-number-3-engine-struts/documents"}}