AD/F50/71 - Wings - Bottom Skin Access Covers

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, were introduced to address the need for comprehensive safety standards and regulations in civil aviation. Part 39 - 105, concerning Airworthiness Directives, aims to ensure that aircraft, including specific models like the Fokker F50 series, meet rigorous safety standards. One such Airworthiness Directive, AD/F50/71, focuses on the maintenance of the bottom skin access covers of Fokker F50 (F27 Mk 50) series aeroplanes. This directive was implemented to mitigate the risk of fatigue cracking in the centre wing bottom skin due to improper seating of heads of certain screws, a problem identified in serial numbers 20103 to 20263 of the model. The requirement is for actions to be taken in accordance with Fokker Service Bulletin F50-57-015, with compliance mandated before the aircraft accumulates 24,000 flight cycles since new. This directive has been in effect since 18 July 1996, reinforcing the Civil Aviation Safety Authority's commitment to maintaining high safety standards in aviation. The Civil Aviation (Airworthiness) Regulations 1998, as part of the broader Civil Aviation Regulations, are instrumental in ensuring that civil aviation operations in Australia adhere to stringent safety and airworthiness standards. These regulations, administered by the Civil Aviation Safety Authority, encompass a wide range of directives aimed at preventing accidents and enhancing the safety of aircraft operations. Specifically, the directive AD/F50/71 addresses a critical safety issue identified in the Fokker F50 series aeroplanes, targeting the maintenance of access covers on the wings to prevent potential structural failure. The directive mandates that corrective action be taken before the aircraft reaches a significant flight cycle threshold, thereby aiming to proactively address and mitigate safety risks associated with this particular model. This legislative measure underscores the authority's role in continuously updating and enforcing safety protocols to safeguard the aviation industry.

Scope and Application

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, pertains to Airworthiness Directives, and in this instance, applies to Fokker F50 (F27 Mk 50) Series Aeroplanes with serial numbers ranging from 20103 to 20263. This legislation mandates that actions must be taken in accordance with Fokker Service Bulletin F50-57-015 to address issues identified with the bottom skin access covers of the wings. The directive is applicable prior to the aircraft accumulating 24,000 flight cycles since it was new and has been effective since 18 July 1996. The directive references RLD BLA 1996-042(A), indicating the regulatory background and the specific safety concerns identified, such as the potential for unequal loads and fatigue cracking in the centre wing bottom skin due to improperly seated heads of certain countersunk screws. This legislation is designed to ensure the safety and airworthiness of the specified Fokker F50 aircraft models within the Australian jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes a schedule of airworthiness directives that govern the maintenance and safety standards of various aircraft types, including the Fokker F50 (F27 Mk 50) series aeroplanes. Section AD/F50/71 pertains to the wings' bottom skin access covers of these aircraft. The directive mandates that action must be taken in accordance with Fokker Service Bulletin F50-57-015 (paragraph 1). This directive applies to Fokker F27 Mk 050 model aircraft with serial numbers ranging from 20103 to 20263 (paragraph 2). The requirement is to address the condition where the heads of certain countersunk screws, which attach access panels P/N 923AB and 924AB, have been found not to seat properly (paragraph 3). This improper seating can lead to unequal loads and subsequent fatigue cracking in the rabbets of the centre wing bottom skin. Compliance with this directive must occur before the aircraft accumulates 24,000 flight cycles since it was new (paragraph 4). The directive came into effect on 18 July 1996 (paragraph 5). Under the Civil Aviation Regulations 1998, operators and maintenance providers of Fokker F50 series aeroplanes are obligated to ensure compliance with the specified airworthiness directive. This includes performing the actions detailed in Fokker Service Bulletin F50-57-015 to address the issue of improperly seated screws on the access covers of the wings' bottom skin. Operators must verify that the required actions are completed before the aircraft reaches 24,000 flight cycles since it was manufactured. This requirement ensures that the aircraft maintains its airworthiness and safety standards, mitigating the risk of fatigue cracking and subsequent structural failures. Failure to comply with the provisions of AD/F50/71 could result in significant safety risks for the aircraft, potentially leading to structural failure and compromised flight safety. The Civil Aviation Regulations 1998 impose obligations on operators and maintenance providers to adhere strictly to the airworthiness directives to prevent such risks. Non-compliance may result in enforcement actions under the Civil Aviation Act 1988, including potential penalties and sanctions. The maximum penalties for breaches of these regulations can include fines and other civil or criminal consequences, reflecting the seriousness of ensuring aircraft safety and airworthiness.