{"id":"F2008L01241","name":"AD/SF340/105 - Landing Gear - Emergency Extension Valve","slug":"ad-sf340-105-landing-gear-emergency-extension-valve","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":73479,"registerId":"commonwealth-F2008L01241-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"SAAB SF340 Series Aeroplanes","sectionType":"division","heading":"SAAB SF340 Series Aeroplanes","content":"### SAAB SF340 Series Aeroplanes\n\n| AD/SF340/105 | Landing Gear - Emergency Extension Valve | 5/2008 |\n| ------------ | ---------------------------------------- | ------ |\n\n| Applicability: | SAAB AB, Saab Aerosystems SAAB SF340A and 340B aeroplanes.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Perform a functional check of the landing gear emergency extension valve in accordance with SAAB Service Bulletin (SB) 340-32-136 or later NAA approved revision; or in accordance with SAAB 340 MRB Report, Section F, Revision 6, task number 323106.2. When, during any of the functional checks as detailed in Requirement 1 of this AD, discrepancies are found, restore functionality. A full system description is provided in the SAAB 340 Aircraft Maintenance Manual (AMM), Chapter 32.Note: EASA AD 2008-0054 dated 5 March 2008 refers.                                                                                                                                                                                                                                                                                  |\n| Compliance:    | 1. Within the next 6 months after the effective date of this AD, and repetitively thereafter at intervals not to exceed 2 years.2. Before further flight, after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n|                | This Airworthiness Directive becomes effective on 8 May 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |\n| Background:    | Several landing gear emergency extension valves have been found seized when performing checks according to the SAAB 340 Maintenance Review Board (MRB) Report, Section F (Airworthiness Limitation Section) task number 323106. The valves have seized due to lack of internal lubrication. This condition, if not corrected, could result in malfunctioning of the landing gear release during an operational emergency. Because the valve lubrication performance is dependant on calendar time since last valve operation, SAAB has revised the check to cycle the emergency release handle 5 times and amended the interval in MRB section F from 5,000 FH to every 2 years. For the reasons described above, this AD requires a functional check of the landing gear emergency extension valve at the newly established intervals. |\n\n![](image.001.png)  \nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n6 March 2008","sortOrder":0},{"sectionNumber":"AD/SF340/105","sectionType":"part","heading":"AD/SF340/105","content":"## AD/SF340/105","sortOrder":1},{"sectionNumber":"Landing Gear - Emergency Extension Valve","sectionType":"part","heading":"Landing Gear - Emergency Extension Valve","content":"## Landing Gear - Emergency Extension Valve","sortOrder":2},{"sectionNumber":"5/2008","sectionType":"part","heading":"5/2008","content":"## 5/2008","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":3,"scope_assessment":{"changed":false,"description":"The AD enforces a revised inspection procedure and interval that SAAB introduced after discovering valves seized from lack of internal lubrication. It does not expand the original safety remit beyond addressing landing gear emergency extension valve functionality; rather it implements a tighter calendar‑based inspection interval (every 2 years) and a specific cycling procedure (five cycles) compared with the prior MRB spacing. The change is therefore corrective and focused on the same safety hazard the MRB originally addressed, not a scope expansion to unrelated systems."},"complexity_factors":["Narrow applicability (only SAAB SF340A and SF340B aircraft)","Single substantive requirement (functional check and restore if discrepant)","Four external document references (SAAB SB 340-32-136, MRB Report Section F Rev 6 task 323106.2, AMM Chapter 32, EASA AD 2008-0054)","Two compliance timelines (initial within 6 months; recurrent every 2 years)","Conditional restoration requirement (must restore functionality before further flight when discrepancies found)","Technical detail referenced but contained in external documents (adds cross‑reference complexity)","Minor ambiguity in presentation of compliance items (separate numbered compliance lines)"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- Applies to: all SAAB AB Saab Aerosystems SAAB SF340A and SF340B aeroplanes.\n- Requires operators to carry out a functional check of the landing gear emergency extension valve (the valve used to release the landing gear in an emergency) using one of two manufacturer-approved procedures: SAAB Service Bulletin (SB) 340-32-136 (or a later NAA‑approved revision) or the SAAB 340 Maintenance Review Board (MRB) Report, Section F, Revision 6, task 323106.2. (See “Requirement”.)\n- If the check finds any discrepancy, the valve must be restored to full functionality. The Aircraft Maintenance Manual (AMM), Chapter 32, contains a full system description to support the work. (See “Requirement”.)\n\n**When the work must be done (compliance timing)**\n\n- Initial check: within 6 months of the AD’s effective date.\n- Recurrent checks: thereafter at intervals not to exceed 2 years.\n- If a fault is found during any check, the valve must be made serviceable before the aircraft is returned to flight. (See “Compliance”.)\n\n**Why the regulator issued this (stated reason and the mechanical effect)**\n\n- The manufacturer and regulator found several emergency extension valves seized when checked under the MRB procedure. The seizures were attributed to lack of internal lubrication.\n- SAAB changed the maintenance procedure to cycle the emergency release handle five times during the check, and reduced the inspection interval from a calendar/flight‑hour spacing (previously 5,000 flight hours) to a firm calendar interval of every 2 years. The AD requires those checks at the revised 2‑year interval to ensure the valve remains lubricated and operational.\n\n**Who is affected and who pays**\n\n- Affected parties: aircraft owners/operators of SAAB SF340A/B aeroplanes, maintenance organisations (AMOs/approved engineers) performing the checks, and potentially parts suppliers if valves require repair or replacement.\n- Costs are borne by the aircraft operator: labour and access time for the check, any parts and repair work when discrepancies are found, and the opportunity cost of aircraft downtime while maintenance is done.\n\n**Who decides and how compliance is demonstrated**\n\n- The Civil Aviation Safety Authority enforces the AD. Compliance is demonstrated by following the referenced SAAB SB or MRB task and recording the work in the aircraft maintenance records; if faults are found, records must show restoration before further flight. The AMM provides the system description to guide maintenance.\n\n**Practical effects on operations and incentives**\n\n- Operators must schedule a short, recurring maintenance action (initially within 6 months, then every 2 years) to inspect and cycle the emergency valve; if a fault is found they must repair it before flying. That increases routine maintenance costs and creates occasional downtime risk.\n- The change from a 5,000 flight‑hour spacing to a 2‑year calendar spacing shifts the duty to calendar time rather than utilisation. Lower‑utilisation operators will see inspections sooner relative to flight hours; higher‑utilisation operators may see more frequent checks compared with the previous flight‑hour trigger depending on their utilisation profile.\n- Maintenance shops must follow the specified SB or MRB procedure (or later NAA‑approved revisions), which may advantage operators with established relationships or internal maintenance capability, and increases the value of accessible approved documentation and trained personnel.\n\n**Implementation and compliance risks, and trade‑offs**\n\n- Risk of operational disruption if a valve is found seized and the aircraft is grounded until repaired.\n- Administrative burden: tracking calendar intervals for all affected aircraft and ensuring use of the correct, NAA‑approved revision of the SB or MRB task.\n- The AD relies on external documents (manufacturer SB, MRB, AMM) and NAA approvals for revisions; delays or differences in those documents across jurisdictions can complicate compliance for international operators.\n\n**Where to find the technical instructions**\n\n- The AD references SAAB SB 340-32-136 (or later NAA‑approved revision), SAAB 340 MRB Report Section F Revision 6 task 323106.2, and AMM Chapter 32 for the full system description. The AD also notes related EASA AD 2008-0054.\n\n(References in this summary correspond to the AD’s “Requirement”, “Compliance” and “Background” text.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope. It addresses a specific safety-of-flight issue (seized landing gear emergency extension valves) on a specific aircraft type (SAAB SF340 series). The directive does not expand beyond its original purpose of mandating periodic functional checks and corrective actions for this single component."},"complexity_factors":["Single, specific mechanical component addressed (landing gear emergency extension valve)","Only 2 compliance requirements with clear timeframes (6 months initial, 2 years recurring)","Straightforward conditional logic: 'if discrepancies found, restore functionality'","Minimal cross-referencing (references SAAB Service Bulletin and Maintenance Review Board Report, but does not incorporate them by complex statutory text)","No defined terms section — uses standard aviation terminology","Single background narrative explaining the safety rationale","Total length: approximately 300 words of substantive text"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of SAAB SF340A/B aircraft in Australia to perform a functional check of the landing‑gear emergency extension valve (cycle the emergency release handle five times) within six months and every two years thereafter, and to rectify any faults before the next flight. The valve can seize from lack of internal lubrication; the measure prevents loss of manual gear extension and the risk of a crash landing."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-105-landing-gear-emergency-extension-valve","history":"/api/acts/ad-sf340-105-landing-gear-emergency-extension-valve/history","analysis":"/api/acts/ad-sf340-105-landing-gear-emergency-extension-valve/analysis","conflicts":"/api/acts/ad-sf340-105-landing-gear-emergency-extension-valve/conflicts","importantCases":"/api/acts/ad-sf340-105-landing-gear-emergency-extension-valve/important-cases","documents":"/api/acts/ad-sf340-105-landing-gear-emergency-extension-valve/documents"}}