{"id":"F2006B07488","name":"AD/TSA-600/23 Amdt 1 - Three-Tank Fuel Quantity Indication - Installation","slug":"ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49933,"registerId":"commonwealth-F2006B07488-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TSA-600/23 Amdt 1 - Three-Tank Fuel Quantity Indication - Installation","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)  \nAerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes\n\nAD/TSA-600/23\n\nAmdt 1\n\n  \n\nThree-Tank Fuel Quantity Indication - Installation\n\n  \n6/80\n\nApplicability: All aerostar models 600, 601, 601P. Document: 1. Piper SB No. 600-81; or\n\n2. FAA AD 79-01-05.\n\nCompliance: Within 100 hours time in service after 30 June 1980.\n\nBackground: Installation of a three-tank fuel quantity indicator is part of a general improvement of fuel management for all models of Aerostar aeroplanes. The modification meets the requirements of FAA AD 79-01-05. A stay of compliance was effected while seeking technical justification for the modification from the FAA. The justification received from the FAA was such that no changes to the AD could be substantiated. However, the compliance date has been amended because of a time delay for the additional investigation.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The amendment is narrow and procedural — it only extends the compliance deadline due to investigation delays. The core safety requirement (installing the three-tank fuel indicator) and the affected aircraft population remain unchanged from the original AD."},"complexity_factors":["Very short document (approximately 150 words)","Only 3 defined applicability criteria (specific aircraft models)","Single compliance requirement with clear deadline","No nested exceptions or conditional logic","No cross-references to other legislation beyond citing source documents (Piper Service Bulletin and FAA AD)","Straightforward background explanation without technical procedural detail"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). ADs are legally binding instructions that aircraft owners and operators must follow to fix unsafe conditions in aircraft.\n\n**What it requires:** Owners of specific **Aerostar 600 and 700 series aeroplanes** (models 600, 601, and 601P) must install a **three-tank fuel quantity indicator** — a device that shows how much fuel is in each of the aircraft's three fuel tanks. This improves fuel management and prevents situations where pilots might unexpectedly run out of fuel in one tank while others still have fuel.\n\n**Who must comply:** Anyone who owns or operates the affected Aerostar aircraft models.\n\n**When:** The work must be completed **within 100 hours of flight time** after 30 June 1980.\n\n**Why it matters:** This modification addresses a safety risk identified by the US Federal Aviation Administration (FAA). Better fuel quantity indication helps prevent fuel starvation accidents — a significant cause of aircraft incidents. The directive was slightly delayed from its original schedule while CASA sought additional technical justification from the FAA, but the safety requirement itself remained unchanged."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The substantive requirement—to install a three-tank fuel quantity indicator on all Aerostar 600, 601 and 601P aircraft—remains the same. The only change recorded in the instrument is an amendment to the compliance date due to a delay while additional technical justification was sought; the underlying installation obligation and referenced technical documents were not altered. (Background; Compliance)"},"complexity_factors":["Narrow applicability (specific Aerostar models 600, 601, 601P) limits affected population.","Clear, fixed compliance timeframe (within 100 hours time in service after 30 June 1980) simplifies scheduling.","Dependency on external technical documents (Piper SB No. 600-81 or FAA AD 79-01-05) means practical implementation details are not contained in the instrument itself.","Administrative history note (stay of compliance and amended compliance date) introduces minor interpretive context about timing but does not change substantive requirement.","No multiple compliance paths or complex certification procedures specified within the text; requirement is a single equipment installation."],"plain_english_summary":"This instrument requires owners/operators of Aerostar 600, 601 and 601P aeroplanes to install a three‑tank fuel‑quantity indicator in accordance with Piper Service Bulletin No. 600‑81 or FAA AD 79‑01‑05, within 100 hours TIS after 30 June 1980.  \n\nIt matters because it legally conditions continued operation on the retrofit, shifts costs and downtime to operators, and ties compliance to the referenced technical documents that dictate parts, methods and labour."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation","history":"/api/acts/ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation/history","analysis":"/api/acts/ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation/analysis","conflicts":"/api/acts/ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation/conflicts","importantCases":"/api/acts/ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation/important-cases","documents":"/api/acts/ad-tsa-600-23-amdt-1-three-tank-fuel-quantity-indication-installation/documents"}}