AD/EMB-110/5 Amdt 4 - Flight Control Trim System Bearings

Overview

The Embraer EMB-110 (Bandeirante) Series Aeroplanes AD/EMB-110/5 Amendment 4, published in 1992, is an airworthiness directive issued by the Civil Aviation Safety Authority under the Civil Aviation Regulations 1998. This legislative instrument was introduced to address safety concerns associated with in-flight failures of the control rod terminal in the elevator trim tab of the EMB-110 series aeroplanes, which were attributed to jamming of the trim tab bearing assembly. The policy objective of this directive is to ensure the continued airworthiness of these aircraft by mandating specific inspections and modifications to prevent such failures. The directive applies to all EMB-110 series aeroplanes and requires the disconnection and visual inspection of bearings at specified locations, as well as compliance with certain Embraer service bulletins. This amendment to the airworthiness directive was made in response to a directive issued by the aeroplane's country of origin, which recommended modification actions instead of ongoing repetitive inspections. Compliance with this directive must be achieved within 1500 hours of time in service or 8 months after 3 February 1992, whichever comes first. The directive aims to enhance safety by mitigating the risk of jamming in the trim tab bearing assemblies, thus preventing potential in-flight failures.

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 105, pertains to the airworthiness directives governing Embraer EMB-110 (Bandeirante) Series Aeroplanes. This regulation applies to all EMB-110 series aircraft, demanding adherence to specific requirements related to the flight control trim system bearings. These requirements include the disconnection and visual inspection of the bearings at various critical locations, such as the tube terminals of the elevator, rudder, and aileron trim tab control systems, and the aileron trim tab bellcrank and actuator eyelets. The directive mandates inspections at intervals not exceeding 250 hours of time in service until compliance with the modification requirements, which must be completed within 1500 hours of time in service or 8 months after 3 February 1992, whichever occurs first. The regulation is enforced by the Civil Aviation Safety Authority and applies nationally within Australia. It is noted that compliance with certain Embraer Service Bulletins terminates the inspection requirement, thereby transitioning to the maintenance intervals prescribed in the Maintenance Planning Guide.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39, Section 105, addresses the requirements for maintaining the airworthiness of Embraer EMB-110 (Bandeirante) series aeroplanes through the issuance of Airworthiness Directives (AD). AD/EMB-110/5 Amendment 4 pertains to the flight control trim system bearings. Section (a) mandates that all EMB-110 series aircraft must have their bearings inspected for jamming at the tube terminals of the elevator, rudder, and aileron trim tab control systems, as well as at the aileron trim tab bellcrank and actuator eyelets. Compliance with Embraer Service Bulletin No. 110-27-036 R2 and Brazilian AD 82-06-01 R8 is also required, and certain modifications may terminate specific inspection requirements. The obligations imposed by the Act are clear and must be adhered to by operators of the EMB-110 series aircraft. Operators are required to disconnect and visually inspect the specified bearings for jamming at intervals not exceeding 250 hours of time in service until the modifications outlined in Embraer Service Bulletin No. 110-27-060 R2 are implemented. Additionally, operators must ensure compliance with these inspection and modification requirements within 1500 hours of time in service or eight months from 3 February 1992, whichever comes first. These obligations aim to prevent in-flight failures attributed to bearing jamming. Failure to comply with the provisions of this AD may result in serious safety risks and legal consequences. The Civil Aviation Safety Authority (CASA) has the authority to enforce compliance through various measures, including the issuance of compliance orders, fines, and other regulatory actions. While specific penalties are not detailed in the AD, the overarching Civil Aviation Act 1988 provides for penalties that can include substantial fines and potential imprisonment for serious violations affecting aviation safety.