{"id":"F2006B07012","name":"AD/SF340/81 Amdt 1 - Pitot Static Tubes","slug":"ad-sf340-81-amdt-1-pitot-static-tubes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48658,"registerId":"commonwealth-F2006B07012-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/81 Amdt 1 - Pitot Static Tubes","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\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\n![](image.001.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/SF340/81 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\nSAAB SF340 Series Aeroplanes\n\nAD/SF340/81\n\nAmdt 1\n\n  \nPitot Static Tubes 10/2002\n\nApplicability: Model SF340A aeroplanes, serial numbers (S/N) 004 through 159 inclusive and Model 340B aeroplanes S/N 160 through 459 inclusive.\n\nRequirement: Modify the pitot static system in accordance with Saab Aircraft AB Mandatory Service Bulletin SAAB 340-34-145 dated 1 October 2001.\n\nNote: LFV AD 1-167 refers.\n\nCompliance: Before 31 January 2003.\n\nThis Amendment becomes effective on 3 October 2002.\n\nBackground: The Swedish Luftfartsverket has advised that operators have reported a number of events involving erroneous airspeed indications. In some instances all three airspeed indication systems failed simultaneously. Typically, during descent from cruise altitude one or more airspeed indicators incorrectly show gradually decreasing airspeed, at lower altitudes the correct airspeed is again displayed and no fault can be detected once the aeroplane is on the ground. Investigation revealed that the cause of the incorrect airspeed displays is ice forming in the pitot static tubes.\n\nThe original issue of this Directive required the installation of new left and right main pitot static tubes with increased heating and a new gasket between the tube and aircraft structure that ensures improved thermal insulation. This Amendment contains minor reformatting and extends compliance.\n\nThe original issue of this Airworthiness Directive became effective on 29 November 2001.\n\n![Signature of James Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJames Coyne\n\n![](image.001.png)  \nDelegate of the Civil Aviation Safety Authority 23 August 2002\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 11 September 2002.\n\n  \nPage 1 of 1","sortOrder":0}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of addressing ice formation in pitot static tubes. The changes are limited to minor reformatting and extending the compliance deadline. The substantive safety requirement remains unchanged from the original November 2001 directive."},"complexity_factors":["Single, clearly defined applicability (specific aircraft models and serial numbers)","Single mandatory action with reference to external technical document (Saab Service Bulletin)","No defined terms section or interpretation provisions","No nested exceptions or conditional logic","Straightforward compliance deadline with no alternative methods or phased requirements","Minimal cross-referencing (only one reference to related Swedish aviation authority directive)"],"plain_english_summary":"This safety order requires owners/operators of Saab SF340A (s/n 004–159) and SF340B (s/n 160–459) to modify pitot-static systems—installing heated tubes and improved insulation per Saab Service Bulletin 340-34-145—to prevent ice blockage that can cause erroneous airspeed readings. It revokes and replaces the prior order, extends the compliance deadline to 31 January 2003, and takes effect 3 October 2002."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment did not expand the AD beyond the original technical remedy. The document states it contains only minor reformatting and extends the compliance period. The applicability (models and serial-number ranges) and the required modification (installation per Saab Mandatory Service Bulletin SAAB 340-34-145) remain the same, so the scope of regulated action is unchanged from the original AD aside from the later deadline for compliance."},"complexity_factors":["Single, focused requirement (modify pitot-static system)","Clear, narrow applicability by aircraft model and serial-number ranges (SF340A S/N 004–159; 340B S/N 160–459)","One external normative reference: Saab Mandatory Service Bulletin SAAB 340-34-145 (dated 1 October 2001)","Single compliance deadline (before 31 January 2003)","Minor cross-references only (note refers to LFV AD 1-167; issued under CAR subreg 39.1(1))","No nested exceptions, alternatives or conditional procedures included in the AD text","Amendment status (this is Amdt 1 revoking the earlier AD) contributes little procedural complexity"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- This is a mandatory airworthiness directive (AD) that requires certain Saab SF340 aeroplanes to have their pitot-static system modified. (See the \"Requirement\" section: operators must follow Saab Aircraft AB Mandatory Service Bulletin SAAB 340-34-145 dated 1 October 2001.)\n- It applies to Model SF340A aeroplanes, serial numbers 004–159, and Model 340B aeroplanes, serial numbers 160–459 (see \"Applicability\").\n- The work must be completed by 31 January 2003 (see \"Compliance\").\n\n**Who must act and who pays**\n\n- The aircraft operators (owners/airlines) of the affected Saab SF340 aircraft must arrange and pay for the modification (the AD imposes the obligation on the operator to correct the unsafe condition). The AD requires compliance with the Saab mandatory service bulletin, which defines the parts and procedures to be used.\n\n**Why this matters (official rationale and technical cause)**\n\n- The Swedish aviation authority reported events where airspeed indicators gave erroneous readings during descent and, in some cases, all three airspeed systems failed simultaneously. The investigation linked these events to ice forming in the pitot-static tubes (see \"Background\").\n- The required modification increases pitot-tube heating and improves thermal insulation at the tube-to-structure joint (installation of new left and right main pitot-static tubes and a new gasket), which is intended to prevent ice formation and therefore reduce the risk of incorrect airspeed displays.\n\n**How it affects behaviour and organisations**\n\n- Operators must schedule the modification within the compliance window and follow the Saab service bulletin instructions precisely. That typically means booking maintenance time, acquiring parts specified by the service bulletin, and using qualified maintenance personnel or organisations.\n- Maintenance providers will carry out the work and invoice operators. There is a direct transfer of cost from operators to suppliers/maintenance organisations for parts and labour.\n\n**Costs, incentives and trade-offs**\n\n- Direct costs: parts, labour and aircraft downtime while the modification is fitted. Those are borne by the operator.\n- Incentives: Operators have a regulatory obligation to comply; noncompliance can lead to grounding or enforcement action. The modification also reduces the operational risk of unreliable airspeed readings, which can otherwise cause incident costs and potential revenue loss from unexpected diversions or accidents.\n- Opportunity cost: Aircraft out of service for modification are not available for revenue flights during the work window; operators must balance scheduling the work against service needs.\n- Market effects: The AD creates short-term demand for specific parts and maintenance labour. This benefits authorised Saab parts suppliers and maintenance organisations able to perform the work; it does not restrict who may perform the work beyond standard aviation maintenance qualifications and following the service bulletin.\n\n**Implementation risks and compliance burden**\n\n- Availability risk: If parts or qualified labour are limited, operators may face delays or temporary loss of capacity.\n- Administrative burden: Operators must document compliance and keep records to demonstrate that the AD and the referenced service bulletin were followed.\n- Regulatory discretion: The AD is issued under CAR subregulation 39.1(1) as corrective action for an unsafe condition; the text is prescriptive and leaves little operational discretion other than timing within the compliance date.\n\n**Net mechanics, summarised**\n\n- Who decides: CASA (the delegate named in the AD) mandated the action under the Civil Aviation Regulations. Who acts: operators of the affected Saab SF340 aircraft. What to do: modify pitot-static tubes per Saab Mandatory Service Bulletin SAAB 340-34-145. When: by 31 January 2003. Why: to reduce the risk of airspeed indicator errors caused by ice forming in the pitot-static tubes (see \"Background\")."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-81-amdt-1-pitot-static-tubes","history":"/api/acts/ad-sf340-81-amdt-1-pitot-static-tubes/history","analysis":"/api/acts/ad-sf340-81-amdt-1-pitot-static-tubes/analysis","conflicts":"/api/acts/ad-sf340-81-amdt-1-pitot-static-tubes/conflicts","importantCases":"/api/acts/ad-sf340-81-amdt-1-pitot-static-tubes/important-cases","documents":"/api/acts/ad-sf340-81-amdt-1-pitot-static-tubes/documents"}}