{"id":"F2006B02059","name":"AD/AA-5/26 - Fuel Tanks","slug":"ad-aa-5-26-fuel-tanks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41281,"registerId":"commonwealth-F2006B02059-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/AA-5/26 - Fuel Tanks","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)  \nGulfstream (Grumman American/ American Aviation) AA-5 Series Aeroplanes\n\nAD/AA 5/26 Fuel Tanks 2/90\n\nApplicability: Model AA 5, AA 5A and AA 5B.\n\nRequirement: Inspect the fuel tanks, fuel system, and the electric fuel pump filter for fuel tank sealant contamination in accordance with the instructions specified in Gulfstream Aerospace Corporation Service Bulletin No 176.\n\nNote: FAA AD 89-18-08 Amdt 39-6307 refers.\n\nCompliance: Prior to the issue of the next Maintenance Release after 30 April 1990.\n\nBackground: Integral fuel tanks were sealed at manufacture with sealant which has since been determined to be unsuitable for use in a high- octane fuel environment. Fuel Tank Repair Service Kit No 140 also specified the use of this sealant, but was subsequently reissued containing the correct sealant as Kit No 140A. The requirement of this AD will ensure against possible fuel contamination and/or flow interruption to the engine.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-limited safety directive from 1990 addressing a specific manufacturing defect. It has not expanded beyond its original purpose of ensuring fuel system integrity in affected AA-5 series aircraft."},"complexity_factors":["Single, specific applicability (three aircraft models only)","One clear requirement referencing an external technical document (Service Bulletin No. 176)","Simple compliance deadline tied to a calendar date and operational event (next Maintenance Release)","No defined terms section, no cross-references to other legislation beyond a note about the corresponding FAA directive","Background explanation provided in plain language","Total length: approximately 150 words"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Gulfstream (formerly Grumman American/American Aviation) AA-5 series light aircraft to inspect their fuel systems for a specific manufacturing defect.\n\n**Who it affects:**\n- Owners and operators of **AA-5, AA-5A, and AA-5B model aircraft**\n- Licensed aircraft maintenance engineers who issue Maintenance Releases (the Australian equivalent of an airworthiness certificate that allows a plane to fly)\n\n**The problem:**\nThese aircraft were built with fuel tank sealant that breaks down in high-octane fuel. This can contaminate the fuel and potentially block fuel flow to the engine — obviously a serious flight safety risk. A repair kit that also used the wrong sealant was later corrected.\n\n**What must be done:**\nA detailed inspection of:\n- The fuel tanks themselves\n- The entire fuel system\n- The electric fuel pump filter\n\nThis inspection must follow specific instructions in **Gulfstream Service Bulletin No. 176**.\n\n**When:**\nBefore the aircraft can be legally flown again after **30 April 1990** — specifically, before the next Maintenance Release is issued after that date.\n\n**Why it matters:**\nThis is a **flight-critical safety issue**. Degraded sealant can cause engine failure due to fuel starvation or contamination. The AD ensures all affected aircraft in Australia were inspected and repaired if necessary, preventing potential accidents."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies to the stated models (AA-5, AA-5A, AA-5B) and requires inspection per the manufacturer service bulletin before the next Maintenance Release after 30 April 1990. The instrument does not expand or narrow the set of affected aircraft or the required inspection beyond what is stated in the Applicability, Requirement and Compliance sections; it implements a correction of previously supplied sealant (Background)."},"complexity_factors":["Narrow applicability to three specific aircraft models reduces scope complexity (Applicability).","Compliance tied to the administrative milestone of the next Maintenance Release after a fixed date creates scheduling complexity for operators (Compliance).","Technical compliance requires following a separate manufacturer service bulletin (Gulfstream Service Bulletin No. 176), adding reliance on external technical documentation (Requirement).","Potential remedial work (replacement of sealant or parts) introduces operational and supply-chain complexity for maintenance providers and operators (Background).","Cross-reference to an FAA airworthiness directive adds an external regulatory reference point (Note)."],"plain_english_summary":"Owners, operators and maintenance organisations of Gulfstream AA‑5, AA‑5A and AA‑5B aeroplanes must inspect integral fuel tanks, the fuel system and electric fuel‑pump filter for contamination from an improper tank sealant, using Gulfstream Service Bulletin No. 176. The inspection is required by the next Maintenance Release after 30 April 1990 to guard against fuel contamination or engine flow interruption; remedial work and costs fall to the aircraft owner/operator."}},"importantCases":[],"_links":{"self":"/api/acts/ad-aa-5-26-fuel-tanks","history":"/api/acts/ad-aa-5-26-fuel-tanks/history","analysis":"/api/acts/ad-aa-5-26-fuel-tanks/analysis","conflicts":"/api/acts/ad-aa-5-26-fuel-tanks/conflicts","importantCases":"/api/acts/ad-aa-5-26-fuel-tanks/important-cases","documents":"/api/acts/ad-aa-5-26-fuel-tanks/documents"}}