{"id":"F2006B03028","name":"AD/B747/127 - Engine Mount Bolt Inspection","slug":"ad-b747-127-engine-mount-bolt-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42387,"registerId":"commonwealth-F2006B03028-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/127 - Engine Mount Bolt Inspection","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\nAD/B747/127 Engine Mount Bolt Inspection 9/94\n\nApplicability: Boeing 747 aircraft fitted with Pratt & Whitney JT9D-3 and -7 series engines. Requirement:               Action in accordance with the requirements of FAA AD 94-10-05.\n\nCompliance: Effective 18 August 1994, as specified in the FAA AD.\n\n \n\nBackground: There have been reports of the forward lower engine mount bolts migrating out of the mount due to loss of the retaining nuts.\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\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 safety directive addressing a specific mechanical defect in a specific aircraft/engine combination. It has not expanded beyond its original purpose of mandating bolt inspections."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section — relies entirely on external reference to FAA AD 94-10-05 for technical details","Simple conditional structure: single applicability criterion (aircraft type + engine type)","Single compliance date with reference to external document for specifics","No nested exceptions, cross-references to other Australian legislation, or internal procedural complexity"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of specific Boeing 747 aircraft to inspect the engine mount bolts.\n\n**What it does:**\n- **Applies to:** Boeing 747 planes fitted with Pratt & Whitney JT9D-3 and JT9D-7 series engines\n- **The problem:** There have been reports that the forward lower engine mount bolts can work their way loose because their retaining nuts have fallen off. If a bolt migrates out completely, the engine could detach from the wing — obviously catastrophic.\n- **What must be done:** Operators must follow the inspection and maintenance procedures set out in an American safety order (FAA AD 94-10-05). This typically involves checking the bolts and nuts, and replacing or securing them as needed.\n- **When:** The directive took effect on 18 August 1994, with specific deadlines and intervals as detailed in the US Federal Aviation Administration's directive.\n\n**Why it matters:** Engine mount failures are extremely dangerous. This directive prevents potential in-flight engine separation by catching loose hardware before it becomes a critical failure."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive implements an FAA airworthiness requirement for a specific technical problem: forward lower engine mount bolts migrating due to loss of retaining nuts. It applies to Boeing 747s with Pratt & Whitney JT9D-3 and -7 engines and requires action in accordance with FAA AD 94-10-05. The text does not broaden or narrow that subject matter beyond requiring compliance with the FAA AD; it retains the original scope of addressing the reported bolt migration issue. (Applicability; Requirement; Background)"},"complexity_factors":["External standard incorporation: the AD cross-references FAA AD 94-10-05 rather than stating technical requirements, so understanding and compliance require consulting that separate document (Requirement).","Narrow technical applicability: applies only to Boeing 747 aircraft fitted with Pratt & Whitney JT9D-3 and -7 series engines, requiring operators to check engine/airframe configurations to confirm applicability (Applicability).","Minimal procedural detail in the Australian text: CASA's directive is short and procedural specifics (inspection steps, intervals, corrective actions) are contained in the FAA AD, increasing reliance on the external source (Requirement; Compliance).","Mandatory timing set externally: the effective date and compliance intervals are specified in the FAA AD, creating a legal obligation whose temporal details are not contained in this document (Compliance).","Single-issue focus with regulatory force: despite brevity, the AD creates a binding maintenance obligation under Part 39 and so has direct operational implications for affected aircraft (header referencing Part 39; Applicability)."],"plain_english_summary":"This AD applies to Boeing 747s with Pratt & Whitney JT9D-3 and -7 engines and mandates that operators comply with FAA Airworthiness Directive 94-10-05 (effective 18 Aug 1994) for inspections and corrective action. It was issued to address reports of forward lower engine‑mount bolts migrating due to lost retaining nuts. Affected owners/operators must schedule and fund the required inspections and repairs; no alternative compliance paths are provided."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-127-engine-mount-bolt-inspection","history":"/api/acts/ad-b747-127-engine-mount-bolt-inspection/history","analysis":"/api/acts/ad-b747-127-engine-mount-bolt-inspection/analysis","conflicts":"/api/acts/ad-b747-127-engine-mount-bolt-inspection/conflicts","importantCases":"/api/acts/ad-b747-127-engine-mount-bolt-inspection/important-cases","documents":"/api/acts/ad-b747-127-engine-mount-bolt-inspection/documents"}}