{"id":"F2009L03072","name":"AD/SF340/108 Amdt 2 - Hydraulic System Accumulators","slug":"ad-sf340-108-amdt-2-hydraulic-system-accumulators","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":80695,"registerId":"commonwealth-F2009L03072-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/SF340/108 Amdt 2 | Hydraulic System Accumulators | 9/2009 |\n| ------------------- | ----------------------------- | ------ |\n\n| Applicability: | SAAB AB, SAAB Aerosystems (formerly SAAB Aircraft AB) SF340A and 340B aircraft, which have hydraulic accumulators Part Number (P/N) 08 8423 001 1 orP/N 08 8423 030 1 installed, except accumulators with serial numbers as listed in SAAB Service Bulletin (SB) 340-29-023 dated 10 June 2008 or revision 1 dated3 April 2009.                                                                                                                                                                                                                                                                                                                                                                                                        |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Replace hydraulic accumulators P/N 08 8423 001 1 and P/N 08 8423 030 1 (except those with serial numbers as listed in SAAB SB 340-29-023) with a new or modified accumulator in accordance with SAAB SB 340-29-023 or later approved revision.Replacement of a hydraulic accumulator having P/N 08 8423 001 1 or P/N08 8423 030 1 in accordance with the instructions of SAAB SB-340-29-024 Revision 01 is an acceptable method to comply with the Requirement 1 of this AD.2. Do not install a hydraulic accumulator with P/N 08 8423 001 1 or P/N08 8423 030 1 on any aircraft, except those with serial numbers as listed in SAAB SB 340-29-023 or later approved revision.Note: EASA AD 2008-0146R1 dated 16 April 2009 refers. |\n| Compliance:    | For Requirement 1 - Remains unchanged as detailed in the original issue of this AD as:For accumulators having a manufacturing date of June 2000 or earlier - Within 24 months after 25 September 2008 (the effective date of the original issue of this AD).For accumulators having a manufacturing date of July 2000 or later - Within 10 years from the manufacturing date or within 24 months after 25 September 2008, whichever occurs later.For Requirement 2 - After 15 August 2010.                                                                                                                                                                                                                                             |\n|                | This Amendment becomes effective on 27 August 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |\n\n| Background: | Two cases of main hydraulic accumulator failure have been reported, one of which was caused by corrosion. Investigation has shown that a severe failure can occur to any of the four hydraulic accumulators which are installed in the hydraulic compartment. Either one of the two end parts on the accumulator may depart from the pressure vessel due to corrosion. This condition, if not corrected, is likely to degrade the functionality of the hydraulic system, possibly resulting in degradation or total loss of control of the landing gear, flap actuation and brakes.A severe failure during flight may even result in debris penetrating and exiting the fuselage outer skin. When such a failure occurs while the aircraft is on the ground, as in the two reported cases, this may cause severe damage to the fuselage and result in injuries to persons nearby.To address and correct the unsafe condition, a modified hydraulic accumulator has been developed, which is sealed between the barrel and the screw cap and between the screw cap and the end cap.For the reasons described above, this AD requires the replacement of the affected hydraulic accumulators P/N 08 8423 001 1 and P/N 08 8423 030 1, as identified in SAAB SB 340-29-023, with a modified hydraulic accumulator.Since the original issue of this AD, one more case of main hydraulic accumulator failure has been reported, which occurred in flight during final approach. The aeroplane was able to land safely and there were no injuries reported on the aeroplane or on the ground.This amendment corrects the compliance date from 15 September 2008 to25 September 2008 with no change to the requirements. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n15 July 2009","sortOrder":0},{"sectionNumber":"AD/SF340/108 Amdt 2","sectionType":"part","heading":"AD/SF340/108 Amdt 2","content":"## AD/SF340/108 Amdt 2","sortOrder":1},{"sectionNumber":"Hydraulic System Accumulators","sectionType":"part","heading":"Hydraulic System Accumulators","content":"## Hydraulic System Accumulators","sortOrder":2},{"sectionNumber":"9/2009","sectionType":"part","heading":"9/2009","content":"## 9/2009","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment corrects the compliance date from 15 September 2008 to 25 September 2008 but expressly states there is no change to the substantive replacement and installation requirements. The amendment becomes effective 27 August 2009 (Background; Compliance)."},"complexity_factors":["Multiple affected part numbers with serial-number exceptions that require cross-checking against SAAB SB 340-29-023 (Applicability; Requirement).","Staggered compliance deadlines tied to manufacturing date or a fixed deadline, creating record-keeping and scheduling complexity (Compliance).","Mandatory use of external technical documents (SAAB SB 340-29-023 / SB-340-29-024 Revision 01) and acceptance of later approved revisions introduces administrative reliance on manufacturer/Bureau approvals (Requirement).","A firm prohibition on future installation after a set date creates an operational procurement constraint for operators and maintenance organisations (Requirement; Compliance).","Safety-critical nature raises urgency and potential operational disruption during replacement, including need for parts supply and downtime (Background).","Cross-reference to EASA AD 2008-0146R1 adds an international regulatory linkage to track for equivalence or additional requirements (Requirement note)."],"plain_english_summary":"Requires SAAB SF340A/B operators to replace specified hydraulic accumulators (P/N 08‑8423‑001‑1 and 08‑8423‑030‑1) except units with listed serial numbers, and forbids installing those part numbers after 15 August 2010. The rule follows SAAB Service Bulletins as the method of compliance. It aims to prevent accumulator failures (including corrosion and end-cap separation) that can damage the fuselage or impair landing gear, flaps and brakes; operators bear the cost and scheduling burden of parts replacement and modification (Requirement; Compliance)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope. It is a technical correction only — changing one date from 15 September 2008 to 25 September 2008. The safety requirements, affected aircraft, part numbers, and compliance deadlines remain unchanged from the original AD's intent."},"complexity_factors":["Multiple part numbers and serial number exceptions to track (P/N 08 8423 001 1, P/N 08 8423 030 1, plus specific serial number exemptions in SAAB SB 340-29-023)","Tiered compliance dates based on manufacturing date (pre-July 2000 vs post-July 2000)","Cross-reference to external documents (SAAB Service Bulletin 340-29-023 and 340-29-024 Revision 01, EASA AD 2008-0146R1)","Alternative compliance method permitted (using SB-340-29-024 Revision 01 instead of SB 340-29-023)","Amendment structure requires reading across original AD, Amendment 1, and Amendment 2 to understand full compliance timeline"],"plain_english_summary":"This AD requires operators of affected SAAB 340A/340B aircraft to replace specific hydraulic accumulators (parts 08 8423 001 1 and 08 8423 030 1) with approved units and bans installing the faulty parts after 15 Aug 2010. The action addresses catastrophic corrosion that can separate accumulator end caps, risking hydraulic control loss, fuselage debris, and ground injury; one in‑flight failure occurred. Amendment 2 only corrects a date (25 Sep 2008) and does not change the safety requirements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-108-amdt-2-hydraulic-system-accumulators","history":"/api/acts/ad-sf340-108-amdt-2-hydraulic-system-accumulators/history","analysis":"/api/acts/ad-sf340-108-amdt-2-hydraulic-system-accumulators/analysis","conflicts":"/api/acts/ad-sf340-108-amdt-2-hydraulic-system-accumulators/conflicts","importantCases":"/api/acts/ad-sf340-108-amdt-2-hydraulic-system-accumulators/important-cases","documents":"/api/acts/ad-sf340-108-amdt-2-hydraulic-system-accumulators/documents"}}