{"id":"F2006B09884","name":"AD/F50/56 Amdt 1 - Collector Tank Strap Assemblies and Fuel Lines","slug":"ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55016,"registerId":"commonwealth-F2006B09884-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/56 Amdt 1 - Collector Tank Strap Assemblies and Fuel Lines","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)  \nFokker F50 (F27 Mk 50) Series Aeroplanes\n\nAD/F50/56\n\nAmdt 1\n\n  \nCollector Tank Strap Assemblies and Fuel Lines 13/95\n\nApplicability: Fokker F27 Mk 50 aircraft Serial Numbers 20133 to 20199 inclusive.\n\nRequirement: Action in accordance with the technical requirements of the Netherlands Directive BLA 92-099/2 (A) dated 31 August 1995.\n\nNote: Fokker Service Bulletin F50-28-014 and F50-28-018 both refer.\n\nCompliance: Unless previously carried out, as specified in the requirement document with an effective date of 7 December 1995.\n\nBackground: Reports of leaking fuel lines on four different aircraft have been received by the Netherlands Airworthiness Authority. Two of these also included advice of failure of a collector tank support strap which results in movement of the tank imposing abnormal loads on the fuel lines.\n\nThis Amendment is issued to include terminating action for the periodic inspections of the fuel lines.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The Amendment changes the operational scope of prior obligations by adding a terminating action for the periodic inspections of the fuel lines. Previously affected aircraft were subject to ongoing periodic inspections; after completing the corrective work required by Netherlands Directive BLA 92-099/2 (A) (and the referenced Fokker service bulletins), operators can cease those periodic inspections (see final paragraph and “Requirement”)."},"complexity_factors":["Applicability limited to a discrete range of serial numbers (20133–20199), reducing breadth but requiring serial-number checks.","Technical compliance is set by an external foreign directive (Netherlands BLA 92-099/2 (A)) and referenced manufacturer service bulletins (F50-28-014, F50-28-018), requiring operators to obtain and follow multiple documents.","The AD modifies prior inspection requirements by adding a terminating action, creating a one-step compliance decision (do corrective work to stop recurring inspections) rather than an ongoing inspection regime.","A fixed effective/compliance date (7 December 1995) creates timing pressure and potential logistics complexity for scheduling maintenance and parts.","Operational and commercial complexity arises from coordination between regulator (CASA), foreign airworthiness authority technical content, maintenance organisations, and aircraft operators."],"plain_english_summary":"This AD requires operators of Fokker F27 Mk 50 aircraft (S/N 20133–20199) to carry out the inspection and corrective work in Netherlands Directive BLA 92-099/2 (A) and referenced Fokker service bulletins—addressing leaking fuel lines and collector tank support strap issues—by 7 December 1995 (unless already done). Once the corrective work is completed, the prior periodic fuel-line inspections may be discontinued. CASA enforces the AD; owners/operators bear compliance costs; the action responds to reported leaks and strap failures that could cause unsafe loads."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive amendment. The original AD required periodic inspections; Amendment 1 adds terminating action (a permanent repair). This is a routine technical update within the original safety purpose, not scope creep."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined applicability criterion (serial number range)","Single cross-reference to Netherlands technical directive (BLA 92-099/2)","No conditional logic or nested exceptions","Simple compliance structure: do X by Y date unless already done","Background explanation is straightforward narrative"],"plain_english_summary":"This is a **safety directive for specific Fokker F50 aircraft** (serial numbers 20133 to 20199) that requires airlines and operators to fix a dangerous fuel system problem.\n\n**What the problem is:**\n- Fuel lines on these planes have been leaking\n- A metal strap that holds the fuel collector tank in place can fail\n- When the strap fails, the tank moves around and damages the fuel lines\n- This creates a fire risk\n\n**What must be done:**\n- Aircraft operators must follow a technical repair procedure from the Netherlands aviation authority (Directive BLA 92-099/2)\n- This involves inspecting and repairing the fuel lines and tank straps\n- The work had to be completed by 7 December 1995 (unless already done)\n- This updated version (Amendment 1) adds a **permanent fix** that ends the need for repeated inspections\n\n**Who it affects:**\n- Owners and operators of 67 specific Fokker F50 aircraft\n- Maintenance engineers working on these planes\n\n**Why it matters:**\nFuel leaks near engines or hot components can cause catastrophic fires. This directive prevents that by mandating a one-time permanent repair rather than ongoing repeated checks."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines","history":"/api/acts/ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines/history","analysis":"/api/acts/ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines/analysis","conflicts":"/api/acts/ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines/conflicts","importantCases":"/api/acts/ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines/important-cases","documents":"/api/acts/ad-f50-56-amdt-1-collector-tank-strap-assemblies-and-fuel-lines/documents"}}