COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Embraer EMB-120 (Brasilia) Series Aeroplanes
AD/EMB-120/21 Elevator Pitch Trim System 1/98
Applicability: All models EMB-120 aircraft.
Requirement: Action in accordance with Embraer Alert Service Bulletin 120-27-A081 change 1:
Part I: A check to verify the proper installation of the movable backstop into the spiral groove on the pitch trim right control wheel, and the correct travel of the pitch trim tab surface.
Part II: Installation of a support/guide to maintain the moveable backstop inside the spiral groove, on the control pedestal structure.
Note: CTA AD 97-09-08R1 Amdt 39-811 refers.
Compliance: For Part I: Unless already accomplished in accordance with the initial issue of the Requirement document, within 20 hours time in service after 1 January 1998.
For Part II: Unless already accomplished, within 75 hours time in service after 1 January 1998.
This airworthiness directive becomes effective on 1 January 1998.
Background: Reports were received of occurrences of a sudden reversion of the elevator pitch trim tab, during the descent phase, with the automatic pilot engaged in descent mode. The reports indicated that, when the trim control wheel reached the pitch down stop, the auto pilot disengaged and the aircraft suddenly reverted to a pitch up attitude, requiring prompt pilot action to control the aircraft.
Overview
The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, form a comprehensive framework governing aviation safety within the country. Part 39 of these regulations includes specific airworthiness directives designed to address particular safety concerns related to various aircraft models. One such directive, AD/EMB-120/21, pertains to the Embraer EMB-120 (Brasilia) Series Aeroplanes and specifically targets issues related to the elevator pitch trim system. This directive was introduced in response to reports of sudden reversions of the elevator pitch trim tab during descent, which posed significant safety risks. The Civil Aviation Safety Authority, through this directive, aims to ensure the proper installation and functionality of the pitch trim system to mitigate such risks and maintain the safety standards of the aircraft.
The directive mandates specific actions, including a check to verify the installation of the movable backstop and the correct travel of the pitch trim tab surface, as well as the installation of a support/guide on the control pedestal structure. Compliance with these requirements is necessary within specified hours of time in service following the directive's effective date of 1 January 1998. This legislative instrument underscores the importance of ongoing safety assessments and corrective measures to address identified issues in aircraft systems, ensuring the highest safety standards are maintained in Australian aviation.
Scope and Application
The Civil Aviation Safety Authority (CASA) issued the Embraer EMB-120 (Brasilia) Series Aeroplanes AD/EMB-120/21 airworthiness directive under the Civil Aviation Regulations 1998, targeting all models of EMB-120 aircraft. This directive applies to all aircraft operators and entities involved in the maintenance and operation of the specified aircraft within Australia. The geographic and jurisdictional reach of this legislation is national, as it is governed by the Commonwealth of Australia through CASA. The directive mandates compliance with specific technical requirements concerning the elevator pitch trim system to ensure the safety of the aircraft. Part I of the directive requires a check to verify the proper installation of the movable backstop and correct travel of the pitch trim tab surface, which must be completed within 20 hours of time in service after 1 January 1998, unless already accomplished. Part II requires the installation of a support/guide to maintain the movable backstop inside the spiral groove on the control pedestal structure, to be completed within 75 hours of time in service after 1 January 1998, unless already done. The directive becomes effective on 1 January 1998, following reports of sudden pitch reversions during descent that necessitated immediate pilot intervention.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate the application of certain airworthiness directives for Embraer EMB-120 (Brasilia) Series Aeroplanes. Section 39 - 105 AD/EMB-120/21, pertaining to the Elevator Pitch Trim System, requires operators to perform specific actions to ensure the safe operation of the aircraft. The directive is divided into two parts: Part I requires a verification check of the movable backstop's proper installation and the pitch trim tab surface's correct travel, while Part II mandates the installation of a support/guide to maintain the movable backstop inside the spiral groove on the control pedestal structure.
Operators of the EMB-120 aircraft are obligated to comply with the specified actions within certain timeframes. For Part I, the verification check must be completed within 20 hours of time in service after 1 January 1998, unless it has already been performed in accordance with the initial requirement document. Part II requires the installation of the support/guide within 75 hours of time in service after 1 January 1998, unless it has already been done. Failure to adhere to these requirements may compromise the airworthiness of the aircraft and lead to severe operational issues.
Breach of the compliance requirements outlined in the airworthiness directive may have significant legal consequences. The Civil Aviation Safety Authority (CASA) may impose penalties on operators for non-compliance, which could include fines and other enforcement actions. The severity of the penalties depends on the extent and nature of the non-compliance, but they can be substantial due to the critical nature of the safety measures involved. Ensuring compliance with these directives is essential to maintaining the safety standards mandated by Australian aviation law.