{"id":"F2006B09871","name":"AD/F50/44 - Fuselage - Flight Compartment Window Frames -2","slug":"ad-f50-44-fuselage-flight-compartment-window-frames-2","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54982,"registerId":"commonwealth-F2006B09871-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/44 - Fuselage - Flight Compartment Window Frames -2","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/F50/44 Fuselage \\- Flight Compartment Window Frames \\-2 9/91\n\nApplicability: All F50 aircraft serial numbers 20103 to 20108 inclusive; 20110 to 20149 inclusive, 20151 to 20155 inclusive, 20159 and 20160.\n\nRequirement: Action in accordance with the Technical Requirements of Netherlands AD BLA 90-002, dated 10 January 1990.\n\nCompliance: Prior to accumulating 15,000 pressurization cycles.\n\nBackground: Full-scale fatigue tests indicated cracks occurring in the edges of the window frames.\n\nThese edges are sharp, which creates local stress concentrations. To remove these stress concentrations, AD/F50/43 was issued, calling for outside edges of the flight compartment window frames to be modified around the sliding windows and the direct vision windows.\n\nThis AD calls for a similar modification to the outside edges of the windshield frames and reinforcing plates to be installed to the window frames of the sliding windows, direct vision windows and windshields.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural fatigue issue on a specific aircraft type. It has not expanded beyond its original purpose of mandating window frame modifications."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly understood (pressurization cycles)","Single compliance requirement with clear deadline (15,000 cycles)","No cross-references to other legislation beyond a single reference to a Netherlands AD (technical standard)","No conditional logic or nested exceptions","Straightforward applicability list (specific serial numbers)"],"plain_english_summary":"This AD requires owners/operators of about 50 Fokker F50 aircraft (serial numbers roughly 20103–20160, with gaps) to modify cockpit window frames — smoothing windshield frame edges and adding reinforcing plates to sliding, direct-vision and windshield frames — before 15,000 pressurization cycles.  \n\nIt prevents fatigue cracks from sharp-frame stress points that could lead to sudden decompression, closing a gap left by an earlier AD and addressing a serious safety risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This AD extends the earlier corrective measure (AD/F50/43) by adding outside‑edge modifications to windshield frames and requiring reinforcing plates for sliding windows, direct vision windows and windshields (\"This AD calls for a similar modification ... to the outside edges of the windshield frames and reinforcing plates to be installed\")."},"complexity_factors":["Applicability limited to a defined list of serial numbers (Applicability: All F50 aircraft serial numbers 20103 to 20160, with some gaps).","Cross‑reference to a foreign airworthiness directive for technical steps (Requirement: Action in accordance with the Technical Requirements of Netherlands AD BLA 90-002, dated 10 January 1990).","Fixed operational compliance trigger based on airframe usage (Compliance: Prior to accumulating 15,000 pressurization cycles).","Scope of work requires structural modification and installation of reinforcing plates (This AD calls for ... modification to the outside edges of the windshield frames and reinforcing plates to be installed).","Root cause is technical fatigue testing rather than on‑fleet reports (Background: Full‑scale fatigue tests indicated cracks occurring in the edges of the window frames)."],"plain_english_summary":"Requires operators of specified Fokker F50 serial numbers to modify the outside edges of flight‑compartment window and windshield frames and fit reinforcing plates, following the technical steps in Netherlands AD BLA 90‑002, before accumulating 15,000 pressurisation cycles. The directive responds to full‑scale fatigue tests that found cracks at sharp window‑frame edges and makes the specified structural modifications mandatory to remove local stress concentrations and avoid further cracking."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-44-fuselage-flight-compartment-window-frames-2","history":"/api/acts/ad-f50-44-fuselage-flight-compartment-window-frames-2/history","analysis":"/api/acts/ad-f50-44-fuselage-flight-compartment-window-frames-2/analysis","conflicts":"/api/acts/ad-f50-44-fuselage-flight-compartment-window-frames-2/conflicts","importantCases":"/api/acts/ad-f50-44-fuselage-flight-compartment-window-frames-2/important-cases","documents":"/api/acts/ad-f50-44-fuselage-flight-compartment-window-frames-2/documents"}}