{"id":"F2008L01515","name":"AD/B737/324 - Forward and Aft Water Drain Masts","slug":"ad-b737-324-forward-and-aft-water-drain-masts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":119909,"registerId":"commonwealth-F2008L01515-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 737 Series Aeroplanes","sectionType":"division","heading":"Boeing 737 Series Aeroplanes","content":"### Boeing 737 Series Aeroplanes\n\n| AD/B737/324 | Forward and Aft Water Drain Masts | 6/2008 |\n| ----------- | --------------------------------- | ------ |\n\n| Applicability: | Model 737-600, -700, -700C, -800, and -900 series aircraft; as identified in Boeing Special Attention Service Bulletin 737-30-1056 Revision 1, or later FAA approved revision.                                                                                                                                                                                                                                                            |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the technical requirements of FAA AD 2008-08-22 Amdt 39-15476.                                                                                                                                                                                                                                                                                                                                                  |\n| Compliance:    | As specified in the Requirement document, with a revised effective date of5 June 2008.                                                                                                                                                                                                                                                                                                                                                    |\n|                | This Airworthiness Directive becomes effective on 5 June 2008.                                                                                                                                                                                                                                                                                                                                                                            |\n| Background:    | The FAA received a report of charred insulation blankets and burned wires around the forward grey water composite drain mast found during an inspection of the forward cargo compartment on a Model 767-300F aircraft. The actions required by this Directive are intended to prevent a fire near a composite drain mast and possible disruption of the electrical power system caused by a lightning strike on the composite drain mast. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n23 April 2008","sortOrder":0},{"sectionNumber":"AD/B737/324","sectionType":"part","heading":"AD/B737/324","content":"## AD/B737/324","sortOrder":1},{"sectionNumber":"Forward and Aft Water Drain Masts","sectionType":"part","heading":"Forward and Aft Water Drain Masts","content":"## Forward and Aft Water Drain Masts","sortOrder":2},{"sectionNumber":"6/2008","sectionType":"part","heading":"6/2008","content":"## 6/2008","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The Directive adopts the FAA AD's technical requirements for the identified 737 submodels and does not expand or narrow the set of affected aircraft beyond those listed (Applicability; Requirement). It implements mitigation measures responding to the reported damage around a composite drain mast (Background) and sets an effective compliance date (Compliance)."},"complexity_factors":["Dependence on external normative documents (FAA AD 2008-08-22 and Boeing SB 737-30-1056 Rev 1) increases procedural complexity and document-tracking burden (Requirement).","Technical, engineering work (inspection, modification or replacement of drain masts and associated wiring) requires specialised maintenance capability and parts.","Limited applicability to specific 737 submodels requires operators to determine affected fleet subsets (Applicability).","Safety-critical nature raises compliance urgency and documentation/audit requirements (Background).","Fixed compliance/effective date imposes scheduling and possible downtime costs on operators (Compliance).","Regulatory delegation: CASA delegate issued the instrument, so enforcement and interpretation rest with the authority (signature/effective date)."],"plain_english_summary":"This Airworthiness Directive requires operators of Boeing 737-600, -700, -700C, -800 and -900 series aircraft (Applicability) to perform the technical actions set out in FAA AD 2008-08-22 and Boeing Special Attention Service Bulletin 737-30-1056 Rev 1 (Requirement). It responds to a report of charred insulation and burned wires around a composite forward grey water drain mast and aims to prevent fire and electrical disruption from lightning strikes; operators bear the cost and must comply by 5 June 2008 (Background; Compliance)."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive adopting an external safety order. It has not expanded beyond its original purpose of addressing the specific lightning strike/fire hazard on water drain masts."},"complexity_factors":["Very short document (under 300 words)","Only 1 substantive requirement: comply with external FAA directive","No defined terms section — relies entirely on external technical document","Simple applicability table with 5 aircraft models","Single compliance date with no conditional deadlines or exceptions","No internal cross-references or nested provisions"],"plain_english_summary":"This CASA Airworthiness Directive requires operators of Boeing 737-600/-700/-700C/-800/-900 series to inspect and repair the composite forward and aft water drain masts that carry grey water. It adopts FAA AD 2008-08-22 after lightning-related charring and wiring/fire risks were found on similar aircraft, and makes compliance mandatory in Australia by 5 June 2008 to prevent electrical failures or cargo fires."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-324-forward-and-aft-water-drain-masts","history":"/api/acts/ad-b737-324-forward-and-aft-water-drain-masts/history","analysis":"/api/acts/ad-b737-324-forward-and-aft-water-drain-masts/analysis","conflicts":"/api/acts/ad-b737-324-forward-and-aft-water-drain-masts/conflicts","importantCases":"/api/acts/ad-b737-324-forward-and-aft-water-drain-masts/important-cases","documents":"/api/acts/ad-b737-324-forward-and-aft-water-drain-masts/documents"}}