{"id":"F2006B07485","name":"AD/TSA-600/20 - Fuel Filler Cap Leakage - Testing","slug":"ad-tsa-600-20-fuel-filler-cap-leakage-testing","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49923,"registerId":"commonwealth-F2006B07485-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/TSA-600/20 - Fuel Filler Cap Leakage - Testing","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Aerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes\n\n \n\nAD/TSA-600/20 Fuel Filler Cap Leakage - Testing 6/79\n\nApplicability: All models.\n\n \n\nDocument: Piper Aerostar SB No. 600-77, Part II only. Compliance: As detailed in the requirements document.\n\nBackground: Tests carried out on the Aerostar fuel system by the FAA have highlighted the importance of maintaining a proper seal with the wing tank filler caps. Leakage past the cap(s) will reduce the amount of fuel flow to the fuselage tank, causing that tank to be prematurely depleted whilst an appreciable amount of fuel remains in the affected wing tank(s). This condition has resulted in a number of forced landings in the U.S.A.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text does not indicate any change to scope from the instrument's apparent original intent. The directive applies to all Aerostar 600/700 models and directs compliance with the specified part of Piper Aerostar SB No. 600-77 (Part II). There is no text in the instrument suggesting an expansion or narrowing of affected aircraft or obligations beyond that stated (Applicability: All models; Document: Piper Aerostar SB No. 600-77, Part II only; Compliance: As detailed in the requirements document.)."},"complexity_factors":["Short directive text that delegates procedural detail to an external service bulletin (Piper Aerostar SB No. 600-77, Part II), requiring operators to obtain and follow that document.","Safety-critical technical subject matter (fuel filler cap sealing and fuel flow) that requires certified maintenance skills and equipment to test and, if necessary, repair.","Applicability to all models of the Aerostar 600/700 series, increasing the population of affected operators and maintenance events.","Limited on-face procedural detail in the AD increases administrative steps and potential for implementation delays (need to source and interpret the referenced SB).","Regulatory enforcement is prescriptive (directive to comply as per requirements document) leaving little operational discretion for operators in meeting the mandate."],"plain_english_summary":"This AD requires owners/operators and maintenance organisations for Aerostar (Piper/Ted Smith) 600 and 700 series aeroplanes to perform the testing and corrective maintenance for wing fuel filler caps as specified in Piper Aerostar SB No. 600‑77 Part II to ensure proper sealing. It was issued after FAA testing showed cap leakage can cause fuel starvation and forced landings. Compliance costs fall to operators/maintenance providers; the directive is issued under CASA authority."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a narrow, specific safety purpose — addressing fuel cap leakage on particular aircraft models. It has not expanded beyond its original technical safety intent."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 defined term implicitly referenced (the service bulletin)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional structure: applicability statement + compliance requirement","No nested exceptions or complex logical operators","Single compliance pathway with no alternatives"],"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 Piper Aerostar aircraft.\n\n**What it does:**\n- Requires owners and operators of **Aerostar 600 and 700 series aeroplanes** to carry out specific tests on their fuel filler caps\n- The testing procedure is found in **Piper Service Bulletin 600-77, Part II only**\n\n**Why it matters:**\n- The FAA (American aviation regulator) discovered that if fuel filler caps don't seal properly, fuel leaks past them instead of flowing to the main fuselage tank\n- This causes the main tank to run dry **while there's still plenty of fuel in the wing tanks** — a dangerous situation that has already caused multiple emergency landings in the United States\n- The directive prevents aircraft from running out of usable fuel unexpectedly\n\n**Who must comply:**\n- Anyone operating these specific Aerostar models (all variants included)\n- Compliance must follow exactly what's written in the referenced Piper service bulletin\n\n**Bottom line:** If you own or fly one of these planes, you must test your fuel caps to make sure they're not leaking — or risk your engine stopping mid-flight due to fuel starvation even when your gauges say you have fuel remaining."}},"importantCases":[],"_links":{"self":"/api/acts/ad-tsa-600-20-fuel-filler-cap-leakage-testing","history":"/api/acts/ad-tsa-600-20-fuel-filler-cap-leakage-testing/history","analysis":"/api/acts/ad-tsa-600-20-fuel-filler-cap-leakage-testing/analysis","conflicts":"/api/acts/ad-tsa-600-20-fuel-filler-cap-leakage-testing/conflicts","importantCases":"/api/acts/ad-tsa-600-20-fuel-filler-cap-leakage-testing/important-cases","documents":"/api/acts/ad-tsa-600-20-fuel-filler-cap-leakage-testing/documents"}}