AD/F50/52 - Cockpit Window Post Attach Angles

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA), were enacted to ensure the safety of civil aviation operations within Australia. Part 39 - 105 of these regulations pertains to airworthiness directives, which are legally enforceable rules regarding the design, production, and maintenance of aircraft. One such directive, AD/F50/52, applies specifically to Fokker F50 (F27 Mk 50) series aeroplanes, mandating modifications to the cockpit window post attach angles to address identified safety concerns. This directive was introduced in response to findings from fatigue tests that revealed potential structural weaknesses in the window post attachments, which could compromise the aircraft's integrity over time. The policy objective of AD/F50/52 is to mitigate these risks by requiring the replacement of existing aluminium alloy angles with corrosion-resistant steel angles, thereby extending the fatigue life of the window posts and enhancing overall aircraft safety. The requirement outlined in AD/F50/52 is that the specified modifications must be completed before the aircraft accumulates 30,000 flight cycles. This directive references Fokker Service Bulletin F50-53-029 dated 1 August 1990 and also notes the relevance of RLD AD (BLA) 90-084. The directive's applicability extends to Fokker F50 series aeroplanes with specific serial numbers, ensuring that only the affected aircraft undergo the necessary modifications. This targeted approach aims to address the identified safety issues effectively without unnecessarily burdening other aircraft models.

Scope and Application

The Civil Aviation Regulations 1998, as amended, establish a comprehensive regulatory framework for civil aviation in Australia, with Part 39 focusing on airworthiness directives. Within this part, Schedule 105 specifically addresses airworthiness directives for Fokker F50 (F27 Mk 50) series aeroplanes, including the directive AD/F50/52 concerning the cockpit window post attach angles. This directive applies to Fokker F50 series aeroplanes with specific serial numbers, namely those ranging from 20103 to 20108 inclusive, 20110 to 20149 inclusive, and 20151 and 20152. The directive mandates modifications to the cockpit window post attach angles in accordance with Fokker Service Bulletin F50-53-029 dated 1 August 1990, replacing the existing aluminium alloy angles with corrosion-resistant steel angles to mitigate the risk of fatigue cracks observed during a full-scale fatigue test. Compliance with this directive is mandatory before the aircraft accumulates 30,000 flight cycles, ensuring the ongoing airworthiness and safety of the specified Fokker F50 series aeroplanes. The regulation extends its applicability nationally, overseen by the Civil Aviation Safety Authority.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39, include an Airworthiness Directive (AD) pertaining to Fokker F50 (F27 Mk 50) series aeroplanes. This directive, AD/F50/52, concerns the modification of cockpit window post attach angles (section 105). The directive applies to Fokker F50 aircraft with serial numbers 20103 to 20108, 20110 to 20149, and 20151 and 20152 (section 4/92). The directive mandates that these aircraft must be modified in accordance with Fokker Service Bulletin F50-53-029 dated 1 August 1990. This modification is referenced in RLD AD (BLA) 90-084 and requires compliance before the aircraft accumulates 30,000 flight cycles (section Applicability). The AD imposes specific obligations on the parties responsible for the Fokker F50 series aeroplanes listed. The primary obligation is to ensure that the cockpit window post attach angles are modified as per the specified service bulletin. This involves replacing the existing 16 aluminium alloy angles with corrosion-resistant steel angles to extend the fatigue life of the window posts. The modifications must be completed before the aircraft reaches 30,000 flight cycles, ensuring the structural integrity and safety of the aircraft are maintained throughout its operational life. Failure to comply with the requirements of AD/F50/52 may result in significant legal and safety consequences. While the specific penalties for non-compliance are not detailed in the text, under the Civil Aviation Act 1988, non-compliance with an airworthiness directive can result in both civil and criminal penalties. Civil penalties may include fines and the possibility of grounding the aircraft until compliance is achieved. In more severe cases, criminal penalties may apply, potentially involving imprisonment or substantial fines, depending on the severity and impact of the non-compliance on aviation safety.