{"id":"F2008L00178","name":"AD/B767/234 - Cargo Compartment Fire Extinguishing System - Time Delay Relays","slug":"ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":72364,"registerId":"commonwealth-F2008L00178-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Boeing 767 Series Aeroplanes","sectionType":"division","heading":"Boeing 767 Series Aeroplanes","content":"### Boeing 767 Series Aeroplanes\n\n| AD/B767/234 | Cargo Compartment FireExtinguishing System - Time Delay Relays | 2/2008 |\n| ----------- | -------------------------------------------------------------- | ------ |\n\n| Applicability: | Model 767-200, 767-300 and 767-300F series aeroplanes as identified in Boeing Special Attention Service Bulletin (SASB) 767-26-0131, dated 24 July 2006.                                                                                                                                                                                                    |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Carry out general visual inspection, in accordance with SASB 767-26-0131 of part number (P/N) TDH6103-1804 time delay relay (K826) in the main equipment centre to determine if the relay was manufactured during a certain date range.                                                                                                                  |\n|                | 2. If, as a result of the Requirement 1 inspection, a relay manufactured during the date range specified in the SASB is found, replace the relay with a relay that was not manufactured during the specified date range, or with a relay that has been tested by the supplier and found to be unaffected by thermal expansion, in accordance with the SASB. |\n|                | 3. Time delay relay, P/N TDH6103-1804, may not be installed on any aeroplane as a replacement spare, if the relay has a date code between 0000 and 0343 and does not have an additional date code with the letter \"T.''                                                                                                                                     |\n|                | Later revisions of the above SASB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-23-08, are considered acceptable for compliance with the equivalent Requirements of this Directive.                                                                                       |\n|                | Note: FAA AD 2007-23-08 Amdt 12524 refers.                                                                                                                                                                                                                                                                                                                  |\n| Compliance:    | For Requirement 1 - Within 24 months after the effective date of this Directive.                                                                                                                                                                                                                                                                            |\n|                | For Requirement 2 - Within 30 days after finding a relay manufactured during the date range specified in the ASAB.                                                                                                                                                                                                                                          |\n|                | For Requirement 3 - As of the effective date of this Directive                                                                                                                                                                                                                                                                                              |\n|                | This Airworthiness Directive becomes effective on 14 February 2008.                                                                                                                                                                                                                                                                                         |\n\n| Background: | The FAA has advised of a report indicating that failure of a time delay relay in the electrical load management system (ELMS) panel of a Boeing Model 777 led to testing of other time delay relays at Boeing and at the supplier. Similar relays are also used in the cargo fire suppression system controlling when the secondary fire bottles discharge.                                                                 |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This Directive is issued to ensure there is sufficient fire suppressant to control a cargo fire if the aeroplane is more than the relay delay time from a suitable airport, which could result in an uncontrollable fire in the cargo compartment. The Directive requires an inspection to determine the date code of the time delay relay for the cargo fire suppression system and, if necessary, replacing of the relay. |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n10 December 2007","sortOrder":0},{"sectionNumber":"AD/B767/234","sectionType":"part","heading":"AD/B767/234","content":"## AD/B767/234","sortOrder":1},{"sectionNumber":"Cargo Compartment FireExtinguishing Syst","sectionType":"part","heading":"Cargo Compartment FireExtinguishing System - Time Delay Relays","content":"## Cargo Compartment Fire  \nExtinguishing System - Time Delay Relays","sortOrder":2},{"sectionNumber":"2/2008","sectionType":"part","heading":"2/2008","content":"## 2/2008","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The Directive maintains the original safety objective described in its Background: ensure sufficient cargo fire suppressant by inspecting and, if necessary, replacing specified time‑delay relays. It confines action to relays and aircraft identified in Boeing SASB 767-26-0131 and accepts later SASB revisions approved by the FAA as AMOCs; it does not expand scope beyond those parts/aircraft or the stated relay failure concern."},"complexity_factors":["Technical identification of specific part and date codes (Requirement 1 and Requirement 3: P/N TDH6103-1804; date codes 0000–0343 and presence/absence of additional 'T' code)","Conditional remedies requiring either replacement or supplier testing for thermal expansion (Requirement 2: replacement or supplier-tested alternative)","Immediate operational prohibition on fitting certain spare parts (Requirement 3: effective date constraints)","Cross-references to external documents for scope and compliance (Boeing SASB 767-26-0131 and FAA AD 2007-23-08 / AMOC acceptance)","Staggered compliance deadlines creating scheduling and record-keeping burdens (24 months for inspection; 30 days for required replacement)","Applicability limited to aircraft identified in the SASB, requiring operators to check service bulletin applicability to each airframe"],"plain_english_summary":"Requires operators of Boeing 767‑200/300/300F aeroplanes (as listed in Boeing SASB 767‑26‑0131) to visually inspect the time‑delay relay P/N TDH6103‑1804 (K826) in the main equipment centre, replace relays made in a specified manufacture date range or use supplier‑tested replacements, and prohibits certain date‑coded relays as spare replacements. It addresses the risk that a relay failure could delay discharge of secondary cargo fire bottles.\n\nInspections are due within 24 months, replacements within 30 days of finding an affected relay, and the spare‑ban is effective immediately."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific identified defect in a specific aircraft type. The scope remains tightly focused on the cargo fire suppression relay issue as originally identified by the FAA and Boeing. There is no evidence of scope creep or expansion beyond the original safety purpose."},"complexity_factors":["Single, specific technical subject matter (one relay part number)","Three clearly numbered requirements with straightforward conditional logic (if found, then replace)","Only one defined technical reference (the Boeing Service Bulletin SASB 767-26-0131)","Simple date-code based identification system for affected parts","No nested exceptions or complex cross-referencing to other legislation","Clear, single-level compliance deadlines (24 months, 30 days, immediate)","Short document length (approximately 400 words of substantive content)"],"plain_english_summary":"This CASA Airworthiness Directive orders operators of Boeing 767-200/300/300F to inspect a cargo-fire-system timing relay (part TDH6103-1804) and replace units manufactured in date codes 0000–0343 with either later relays or supplier-tested equivalents. The relays can fail from thermal expansion, risking non‑discharge of secondary fire bottles on long flights. Faulty units must be replaced promptly and, from 14 February 2008, those suspect relays are banned as spares. It affects operators, maintenance crews, and parts suppliers."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays","history":"/api/acts/ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays/history","analysis":"/api/acts/ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays/analysis","conflicts":"/api/acts/ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays/conflicts","importantCases":"/api/acts/ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays/important-cases","documents":"/api/acts/ad-b767-234-cargo-compartment-fire-extinguishing-system-time-delay-relays/documents"}}