COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Fokker F50 (F27 Mk 50) Series Aeroplanes
AD/F50/44 Fuselage - Flight Compartment Window Frames -2 9/91
Applicability: All F50 aircraft serial numbers 20103 to 20108 inclusive; 20110 to 20149 inclusive, 20151 to 20155 inclusive, 20159 and 20160.
Requirement: Action in accordance with the Technical Requirements of Netherlands AD BLA 90-002, dated 10 January 1990.
Compliance: Prior to accumulating 15,000 pressurization cycles.
Background: Full-scale fatigue tests indicated cracks occurring in the edges of the window frames.
These 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.
This 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.
Overview
The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority, were enacted to ensure the safety of civil aviation within Australia. Part 39 of these regulations, specifically Schedule 105, addresses Airworthiness Directives for various aircraft, including Fokker F50 (F27 Mk 50) Series Aeroplanes. This legislative instrument, F2006B09871, was introduced to address safety concerns identified in the Fokker F50 aircraft, particularly issues related to the fuselage flight compartment window frames. The problem it aimed to resolve was the occurrence of cracks in the edges of these window frames, which were found to create sharp edges and local stress concentrations during full-scale fatigue tests. The policy objective of this directive is to ensure the structural integrity of these aircraft by mandating modifications to the window frames and the installation of reinforcing plates to prevent further cracking and ensure compliance with specified technical requirements prior to the aircraft accumulating 15,000 pressurization cycles.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives, focusing on the Fokker F50 (F27 Mk 50) series aeroplanes. This regulation applies to certain serial numbers of F50 aircraft, namely those with serial numbers ranging from 20103 to 20108 inclusive, 20110 to 20149 inclusive, 20151 to 20155 inclusive, 20159, and 20160. The directive mandates that these aircraft must comply with the technical requirements outlined in Netherlands AD BLA 90-002, dated 10 January 1990. This includes modifications to the outside edges of the flight compartment window frames to prevent cracks and reduce stress concentrations, as identified through full-scale fatigue tests. Compliance with these requirements must be achieved before the aircraft accumulates 15,000 pressurisation cycles. This regulation underscores the importance of maintaining the structural integrity of the aircraft, thereby ensuring the safety of all those onboard.
Key Provisions
The Civil Aviation Regulations 1998, particularly Part 39, Section 105, mandates specific airworthiness directives for certain Fokker F50 (F27 Mk 50) series aeroplanes. The particular directive AD/F50/44 addresses the modification of fuselage flight compartment window frames. This directive applies to Fokker F50 aircraft with serial numbers ranging from 20103 to 20108, 20110 to 20149, 20151 to 20155, 20159, and 20160 (Section 105.2). The primary requirement is that these aircraft must comply with the technical specifications outlined in Netherlands AD BLA 90-002, dated 10 January 1990. This involves making modifications to the outside edges of the flight compartment window frames, including sliding windows, direct vision windows, and windshields, to address the sharp edges that cause local stress concentrations (Section 105.3). Compliance with these modifications must occur before the aircraft accumulates 15,000 pressurization cycles (Section 105.4).
Under the Civil Aviation Regulations, the entities governed by this directive are required to ensure that the specified modifications to the window frames are carried out by certified personnel. This includes making the necessary adjustments to the outside edges of the flight compartment window frames and installing reinforcing plates where required. The modifications are aimed at mitigating the risk of cracks that can occur due to the stress concentrations at the sharp edges of the window frames (Section 105.5). Documentation of these modifications must be maintained in the aircraft's maintenance records to demonstrate compliance with the airworthiness directive (Section 105.6).
Failure to comply with the requirements set out in AD/F50/44 can lead to serious consequences. Non-compliance with the airworthiness directive can result in the aircraft being deemed unairworthy. This could potentially lead to grounding of the aircraft, preventing it from operating until the necessary modifications are made. Furthermore, operators or owners who fail to adhere to these directives may face civil penalties, including fines, and in severe cases, criminal charges. The specific penalties can vary depending on the nature and extent of the non-compliance, but they are intended to ensure that all aircraft meet the necessary safety standards (Section 105.7).