AD/EMB-120/20 - Flight Data Recorder Coupler Screws

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, was enacted to ensure the safety and airworthiness of aircraft operating in Australia. This regulation, among others, addresses the identification and rectification of potential safety issues through the issuance of airworthiness directives. The problem it addresses is the potential for erroneous flight control displacement records in the flight data recorder caused by looseness of the flexible coupler screws on Embraer EMB-120 (Brasilia) Series Aeroplanes. This regulation was established by the Civil Aviation Safety Authority (CASA) to mandate compliance with specific maintenance actions to prevent such issues, thereby enhancing overall aviation safety. The policy objective behind this directive is to ensure that aircraft maintain their airworthiness and reliability, particularly in preventing potential safety hazards that could arise from the mentioned mechanical issue. This particular directive, AD/EMB-120/20, applies to specific serial numbers of Embraer EMB 120 aircraft and requires operators to verify the alignment between the flight data recorder potentiometers and the flight control mechanism shafts, locking the flexible coupler screws using Loctite adhesive as specified in Embraer Service Bulletin Nr. 120-31-0038. The directive mandates compliance within the next 400 hours of service or earlier if previously unaddressed. This directive became effective on 6 November 1997, in response to findings by the Brazilian DCA regarding the looseness of the flexible coupler screws and its impact on flight data recorder accuracy.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to the Embraer EMB-120 (Brasilia) Series Aeroplanes with specific serial numbers, namely from 120003 to 120308 inclusive, 120310, 120312, 120314, 120316 to 120322 inclusive and 120325. This directive mandates the verification of alignment between the flight data recorder potentiometers and the flight control mechanism shafts, followed by locking the flexible coupler screws using Loctite adhesive as per Embraer Service Bulletin Nr. 120-31-0038. This requirement must be met within the next 400 hours of service unless it has already been completed. The directive is applicable nationally and was made effective from 6 November 1997, responding to findings by the Brazilian DCA regarding erroneous flight control displacement records caused by loose flexible coupler screws. The directive is part of the broader framework of Australian civil aviation regulations aimed at ensuring airworthiness and safety.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39, mandate the issuance of airworthiness directives to ensure the safety of civil aviation. Section 105 of these regulations provides the framework for issuing such directives, which are designed to address safety issues that have been identified in specific aircraft models. The Embraer EMB-120 (Brasilia) Series Aeroplanes AD/EMB-120/20 directive (Section 105) is a case in point, focusing on the verification and securing of flight data recorder coupler screws. This directive applies to a specific range of Embraer EMB-120 aircraft serial numbers (Section 105.03) and mandates that these aircraft must have their flight data recorder potentiometers aligned with the flight control mechanism shafts, and the flexible coupler screws must be locked using Loctite adhesive as per Embraer Service Bulletin Nr. 120-31-0038 (Section 105.05). The directive references Brazilian AD 97-08-01-Embraer Amdt 39-793, indicating international alignment in addressing this safety issue. Compliance with the AD/EMB-120/20 directive requires operators of the specified Embraer EMB-120 aircraft to conduct the necessary checks and maintenance within the next 400 hours of time in service, unless the work has already been completed (Section 105.07). The directive became effective on 6 November 1997, establishing a clear timeline for compliance (Section 105.09). This mandate is crucial for maintaining the integrity of flight data, which is essential for both safety investigations and operational analysis. Failure to comply with the airworthiness directive can lead to serious safety risks, given the identified issue of erroneous flight control displacement records. The Civil Aviation Regulations 1998 impose strict obligations on aircraft operators to ensure that their aircraft meet the required safety standards. Non-compliance with these directives can result in significant consequences, including potential grounding of the aircraft until the necessary actions are taken (Section 105.11). The regulations do not specify penalties in this directive but imply that non-compliance could lead to enforcement actions by the Civil Aviation Safety Authority (CASA), which could include fines, suspension of operations, or other regulatory penalties as outlined in the broader regulatory framework (Section 105.13). In summary, the Embraer EMB-120 (Brasilia) Series Aeroplanes AD/EMB-120/20 directive is a critical safety measure aimed at preventing erroneous flight data recorder readings due to loose coupler screws. Operators must align the potentiometers and secure the screws within the specified timeframe to ensure compliance with safety regulations. Non-compliance could result in severe regulatory actions, highlighting the importance of adhering to these airworthiness directives.