{"id":"F2006B03220","name":"AD/B747/4 - Toilet Areas - Inspection and Modification","slug":"ad-b747-4-toilet-areas-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42592,"registerId":"commonwealth-F2006B03220-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/4 - Toilet Areas - 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\nAD/B747/4 Toilet Areas - Inspection and Modification 12/75\n\nApplicability: All models.\n\n \n\nDocument: FAA AD 74-21-03, Amdt. 39-2376.\n\n \n\nCompliance: Before 1 March 1976.\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\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The instrument, as presented, establishes applicability to all Boeing 747 models, references FAA AD 74-21-03 for the required actions, and sets a compliance deadline of 1 March 1976. There is no indication in the provided text that the scope has been altered from its original intent; the directive is limited to inspection and modification of toilet areas for all models and does not expand or narrow that stated applicability."},"complexity_factors":["Very short directive with only three operative items: applicability, reference to an external FAA AD, and a compliance date.","No technical detail included in the text; compliance requires obtaining and following the referenced FAA AD (Document: FAA AD 74-21-03), adding a step outside this instrument.","Applies to an entire aircraft type class (All models), which broadens operational impact despite the directive’s brevity.","Fixed compliance deadline imposes scheduling constraints and potential operational downtime.","Authority and enforcement context (Part 39–105, CASA) are stated but the instrument does not provide procedures for alternative compliance or approvals, creating potential administrative follow-up."],"plain_english_summary":"Summary\n\n- What the rule does, mechanically: It orders that all Boeing 747 aeroplanes must have their toilet areas inspected and modified in accordance with the referenced FAA airworthiness directive. The local instrument cites FAA AD 74-21-03 as the controlling document for what must be done (Document: FAA AD 74-21-03). Compliance must be completed by 1 March 1976 (Compliance: Before 1 March 1976).\n\n- Who it affects: Owners and operators of Boeing 747 aircraft (Applicability: All models). The Civil Aviation Safety Authority (CASA) publishes this as part of the Schedule of Airworthiness Directives under Part 39–105.\n\n- Why it matters (as stated and as can be inferred from the text): The instrument requires inspection and modification of a specific aircraft area and therefore imposes a mandatory maintenance action. The AD itself does not set out the technical instructions in this text; it points to the FAA AD (Document: FAA AD 74-21-03) for the detailed requirements. The text does not specify the underlying hazard or incident history; it only establishes the mandatory action and deadline.\n\nPractical implications, costs and incentives\n\n- Who pays: Aircraft owners/operators must carry out (or contract out) the inspections and any required modifications (the AD is directed at the fleet operator: Applicability: All models; Compliance: Before 1 March 1976). Any direct labour, parts, and aircraft downtime costs are borne by those operators.\n\n- What must be done and by when: Inspect and modify toilet areas per the referenced FAA AD, and complete that work before 1 March 1976 (Compliance: Before 1 March 1976; Document: FAA AD 74-21-03).\n\n- Compliance burden and implementation risk: The AD is short on technical detail in this text, so operators will need to obtain and follow FAA AD 74-21-03 to learn the exact inspection and modification tasks (Document: FAA AD 74-21-03). That creates an operational step (sourcing and following a foreign AD) and potential scheduling and supply-chain effects (parts, access to qualified technicians). The deadline fixes a time window for action, which can create aircraft downtime and scheduling costs.\n\n- Decision and discretion: The AD itself is a mandatory regulatory instruction. Discretion for how to comply (specifics of carrying out inspections or using alternative methods) is not included in this text and would depend on the FAA AD’s content or any approvals/variations that CASA might grant.\n\nTrade-offs and opportunity costs\n\n- Operators will need to divert maintenance resources and aircraft availability to meet the requirement by the deadline. Those resources (labour, hangar time, parts) cannot be used for other work during that period.\n\n- Because the AD cross-references an FAA document for technical detail, operators outside the United States must rely on that external document for compliance steps; obtaining parts or approved modifications could be affected by international supply or approval processes.\n\nLimitations of the source text\n\n- The instrument does not describe the technical defect, incident history, or specific safety hazard that motivated the actions. It only states the required action, the authority reference (FAA AD 74-21-03), the applicability (All models), and the compliance deadline (Before 1 March 1976). For the specific procedures and rationale, operators must consult the referenced FAA AD (Document: FAA AD 74-21-03)."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue directive from 1975 addressing a specific safety concern (toilet areas). It has not expanded beyond its original narrow scope."},"complexity_factors":["Extremely short — only a few lines of operative text","No defined terms section; relies entirely on external FAA document for technical details","No conditional logic or exceptions within the directive itself","Simple applicability ('All models') with no carve-outs","Single compliance date with no alternative methods or phased approach"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — essentially a mandatory safety order — issued by Australia's Civil Aviation Safety Authority (CASA) for all Boeing 747 aircraft.\n\n**What it requires:** Operators must inspect and modify the toilet areas on their Boeing 747s. The specific technical requirements are found in a US Federal Aviation Administration (FAA) document referenced in the directive (FAA AD 74-21-03).\n\n**Who it affects:** Anyone operating any model of Boeing 747 aircraft in Australia.\n\n**Why it matters:** This directive addresses a safety issue in the aircraft's toilet areas — likely a fire risk or structural problem that could endanger passengers and crew. Airworthiness directives are legally binding; failure to comply means the aircraft cannot fly legally.\n\n**The deadline:** All affected aircraft had to be modified before 1 March 1976.\n\n**Key point:** This is a very old directive from 1975. While it remains on the books, any Boeing 747 still flying today would have had this work done decades ago."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-4-toilet-areas-inspection-and-modification","history":"/api/acts/ad-b747-4-toilet-areas-inspection-and-modification/history","analysis":"/api/acts/ad-b747-4-toilet-areas-inspection-and-modification/analysis","conflicts":"/api/acts/ad-b747-4-toilet-areas-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-b747-4-toilet-areas-inspection-and-modification/important-cases","documents":"/api/acts/ad-b747-4-toilet-areas-inspection-and-modification/documents"}}