{"id":"F2006B07009","name":"AD/SF340/79 Amdt 1 - Improved Air Circulation Fan","slug":"ad-sf340-79-amdt-1-improved-air-circulation-fan","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48650,"registerId":"commonwealth-F2006B07009-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/79 Amdt 1 - Improved Air Circulation Fan","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \n![](image.002.png)  \nSAAB SF340 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/SF340/79 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\nAD/SF340/79\n\nAmdt 1\n\n  \nImproved Air Circulation Fan 8/2001\n\nApplicability: Model SF340A serial numbers \\-004 through \\-108 without SAAB Aircraft AB Service Bulletin (SB) 340-21-018 (Modification 1421) incorporated.\n\nRequirement: 1. Replace the flight compartment and passenger compartment air recirculation fans Part Number (P/N) C209-690C with fans P/N C209-690D in accordance with SAAB SB 340-21-039 dated 23 August 2000.\n\n2. If not previously accomplished in accordance with the original issue of this Directive, replace the flight compartment and passenger compartment air recirculation fans P/N C209-690B, C209-690B1 or C209-690C with fans P/N C209-690D in accordance with SAAB SB 340-21-039 Revision 1 dated 18 April 2001.\n\nIncorporation of optional Modification 1421 (brushless fan motor) is an alternate method of compliance for this Directive.\n\nNote: LFV AD 1-160 refers.\n\nCompliance: For Requirement 1 \\- Remains unchanged as ‘Within 1000 hours time in service after the effective date of the original issue of this Directive’.\n\nFor Requirement 2 \\- Within 500 hours time in service after the effective date of this Amendment.\n\nThis Amendment becomes effective on 9 August 2001.\n\nBackground: The Luftfartsverket received reports of smoke or burning smell in the cabin, caused by incorrect brush insulation in the electric fan motor. The original issue of this Directive required replacement of the air recirculation fans with fans that have an improved motor.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\nThis amendment identifies additional part number fans to be replaced.\n\n![](image.003.png)The original issue of this Directive became effective on 2 November 2000.\n\n![](image.004.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 29 June 2001\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 July 2001.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment expands the scope of the original directive. The original AD only required replacement of P/N C209-690C fans. Amendment 1 adds Requirement 2, which mandates replacement of three additional part numbers (C209-690B, C209-690B1, and C209-690C again for those not caught by the original). The background explicitly states 'This amendment identifies additional part number fans to be replaced.' The scope has grown from one specific fan model to four models, though all relate to the same underlying safety issue."},"complexity_factors":["Multiple part numbers referenced (C209-690B, C209-690B1, C209-690C, C209-690D) with different compliance deadlines","Two-tier applicability: serial number range AND exclusion for aircraft with specific prior modification","Cross-reference to external technical documents (SAAB Service Bulletins 340-21-039 and 340-21-018)","Alternative method of compliance (Modification 1421) creates conditional logic","Different compliance timeframes for Requirement 1 (original issue) vs Requirement 2 (this amendment)","Reference to foreign aviation directive (LFV AD 1-160 from Swedish authority)"],"plain_english_summary":"This safety order requires owners/operators of Saab SF340A aircraft (S/N -004 through -108) that have not had Service Bulletin 340-21-018 installed to replace certain cockpit and cabin air-circulation fans because defective brush insulation can cause smoke or burning smells. It sets short compliance windows for replacing older fan part numbers with an improved part, and allows installing Modification 1421 (brushless motors) as an alternative that removes the fire risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This Amendment broadened the scope of the original Directive by identifying additional fan part numbers to be replaced. The original AD required replacement of P/N C209‑690C; this Amendment adds P/N C209‑690B and C209‑690B1 to the replacement requirement (see “Requirement 2”) and sets a separate compliance window for those additional part numbers. It therefore expands the population of affected components and imposes new compliance timing for operators who still have those earlier part numbers installed."},"complexity_factors":["Single airworthiness issue (fan motor insulation / smoke reports)","Applicability limited to one model and a narrow serial number range (SF340A –004 to –108)","Two numbered requirements with different part numbers and two different SAAB Service Bulletin references","Alternate method of compliance allowed (Modification 1421) introduces a choice between compliance paths","Two differing compliance timeframes (1000 hours for Req 1, 500 hours for Req 2)","Cross‑reference to an earlier AD (original AD) and a foreign AD (LFV AD 1‑160)"],"plain_english_summary":"**What this instrument does (mechanics)**\n\n- This is an Airworthiness Directive (AD) that requires replacement of certain air recirculation fans on specific SAAB SF340A aeroplanes. The replacement must be done following the SAAB service bulletin instructions cited in the AD (SAAB SB 340‑21‑039 or its Revision 1).\n- Two specific actions are required:\n  - Requirement 1: Replace fans with Part Number (P/N) C209‑690C by fans P/N C209‑690D, per SAAB SB 340‑21‑039 dated 23 August 2000 (see “Requirement 1”).\n  - Requirement 2: For operators who have not already complied under the original AD, replace fans with P/N C209‑690B, C209‑690B1 or C209‑690C by fans P/N C209‑690D in accordance with SAAB SB 340‑21‑039 Revision 1 dated 18 April 2001 (see “Requirement 2”).\n- As an alternate method of compliance, operators may incorporate optional Modification 1421 (a brushless fan motor) — i.e. installing Mod 1421 satisfies the AD instead of replacing to P/N C209‑690D (see “Incorporation of optional Modification 1421”).\n- Applicability is limited to SF340A aeroplanes, serial numbers –004 through –108, that do not already have SAAB SB 340‑21‑018 (Modification 1421) incorporated (see “Applicability”).\n- Compliance timing: Requirement 1 was to be done within 1,000 hours time in service after the effective date of the original Directive; Requirement 2 must be done within 500 hours time in service after this Amendment became effective (9 August 2001) (see “Compliance”).\n\n**Who it affects**\n\n- Aircraft operators/owners of SAAB SF340A with serial numbers –004 through –108 that have not incorporated SAAB SB 340‑21‑018 (Modification 1421).\n- Maintenance organisations or engineers who carry out the replacements according to the SAAB service bulletin.\n\n**Why it matters (stated safety issue and mechanics of mitigation)**n\n- The stated safety reason is reports of smoke or a burning smell in the cabin caused by incorrect brush insulation in the electric fan motor (see “Background”). The AD requires replacing the affected fan motors (or installing a brushless motor modification) to remove the hazard.\n\n**Who pays, who decides, and what behaviour changes**\n\n- Who pays: aircraft operators/owners pay for parts, labour and any downtime to comply with the AD unless another commercial arrangement applies. The AD itself does not allocate funding.\n- Who decides: the Civil Aviation Safety Authority (CASA) delegate issued the AD; individual operators decide which approved compliance method to use (replacement to P/N C209‑690D or incorporation of Mod 1421) within the AD’s requirements and time limits.\n- Behaviour changes required: operators must schedule and complete the specified maintenance action within the stated time limits, keep records of compliance, and, if choosing Mod 1421, incorporate that modification as the alternative compliance method.\n\n**Costs, incentives and trade‑offs**\n\n- Direct costs: purchase of replacement fans or Mod 1421 kit, maintenance labour, and aircraft downtime while work is done (cost borne by operator).\n- Incentives: adopting Mod 1421 (brushless motor) is an alternative compliance option — operators may choose it if it offers longer life, lower maintenance, or other operational advantages. The AD creates a compliance deadline that incentivises prompt action.\n- Implementation risk and supply constraints: replacing specific P/N fans depends on parts availability and scheduling; delay in parts or maintenance capacity can increase downtime and costs.\n- Compliance burden: actions must be performed in accordance with the SAAB service bulletin instructions cited; maintenance organisations must follow those instructions and keep records as usual for AD compliance.\n\n**Concrete legal links to the document**\n\n- Applicability and affected serial numbers (see “Applicability”).\n- Required actions and referenced SAAB SBs (see “Requirement 1” and “Requirement 2”).\n- Alternate Method of Compliance (Mod 1421) is explicitly allowed (see “Incorporation of optional Modification 1421”).\n- Compliance times: 1,000 hours for Requirement 1 (original AD); 500 hours after this Amendment for Requirement 2 (see “Compliance”).\n\n**Notes and cross‑references**\n\n- This Amendment expands the list of part numbers captured by the AD (see “Background” and the text of the Amendment).\n- The AD notes a related foreign authority reference (LFV AD 1‑160).\n\n(References in parentheses refer to the labelled sections of the AD: Applicability, Requirement 1, Requirement 2, Incorporation of optional Modification 1421, Compliance, Background.)"},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-79-amdt-1-improved-air-circulation-fan","history":"/api/acts/ad-sf340-79-amdt-1-improved-air-circulation-fan/history","analysis":"/api/acts/ad-sf340-79-amdt-1-improved-air-circulation-fan/analysis","conflicts":"/api/acts/ad-sf340-79-amdt-1-improved-air-circulation-fan/conflicts","importantCases":"/api/acts/ad-sf340-79-amdt-1-improved-air-circulation-fan/important-cases","documents":"/api/acts/ad-sf340-79-amdt-1-improved-air-circulation-fan/documents"}}