AD/B767/93 Amdt 1 - Ram Air Turbine Actuator Motor

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, were enacted by the Parliament of the Commonwealth of Australia to address safety concerns within the aviation sector. The legislation was designed to fill a gap in ensuring that aircraft maintain a high standard of safety and reliability, particularly in the context of the operation of Boeing 767 series aeroplanes. One of the significant issues this legislation aimed to address was the potential failure of the Ram Air Turbine (RAT) actuator due to corrosion, which could lead to critical safety incidents. The Civil Aviation Safety Authority (CASA) developed Airworthiness Directives to mandate regular testing and replacement of RAT components to mitigate these risks. This particular legislative instrument, AD/B767/93 Amendment 1, was introduced to enforce a US Federal Aviation Administration (FAA) directive, AD 96-20-05, and requires all Boeing 767 aircraft to undergo rigorous operational tests of the RAT. The policy objective is to ensure that the RAT deploys correctly to avoid in-flight emergencies, thereby enhancing the overall safety of civil aviation. The amendment became effective on 8 October 1998, following the identification of corroded RAT actuators and an incident where the RAT failed to deploy due to corrosion.

Scope and Application

The Civil Aviation Safety Authority's Schedule of Airworthiness Directives, specifically AD/B767/93 Amendment 1, pertains to all Boeing 767 aircraft and mandates certain operational and maintenance requirements to ensure the safety of the Ram Air Turbine (RAT) system. This legislation applies to the aircraft themselves and the entities responsible for their operation and maintenance. Its jurisdictional reach is national, enforced under the Civil Aviation Regulations 1998, and it incorporates a corresponding directive issued by the United States Federal Aviation Administration (FAA). The directive requires operators to test and, if necessary, replace the rotary actuator motor of the RAT to prevent failures due to corrosion. Compliance involves conducting an initial operational test at 3000 flight hours or within six months of the last RAT deployment, whichever comes later, and subsequent tests every 3000 flight hours or six months, depending on the outcome of the initial test. This amendment became effective on 8 October 1998, building upon the original directive issued on 5 December 1996, which was necessitated by incidents of RAT actuator corrosion and deployment failures.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate certain procedures for maintaining the airworthiness of Boeing 767 series aeroplanes. Under section 105 of the regulations, the Civil Aviation Safety Authority has issued a schedule of airworthiness directives (ADs), with AD/B767/93 Amendment 1 focusing on the Ram Air Turbine (RAT) actuator motor. The primary requirement outlined in this directive (section 1) is that operators must test the RAT in accordance with Boeing Alert Service Bulletin 767-29A0080 Rev 1 dated 21 November 1996 and replace the rotary actuator motor of the RAT. This directive references a similar US Federal Aviation Administration (FAA) AD 96-20-05, indicating a coordinated effort to address safety concerns. Operators of Boeing 767 aircraft must adhere to specific operational testing schedules as mandated by the directive. Section 1 of the directive states that the initial operational test must occur at 3,000 flight hours or within six months of the last deployment of the RAT, whichever is later. If the RAT deploys correctly, subsequent tests must be conducted every 3,000 flight hours or six months, whichever comes first. In the event the RAT does not fully deploy during the operational test, additional procedures must be followed as specified by the directive. Failure to comply with the airworthiness directive carries potential legal and safety repercussions. Under the Civil Aviation Act 1988, non-compliance with airworthiness directives can result in serious consequences, including the potential for grounding of the aircraft, enforcement actions, and significant financial penalties. The directive became effective on 8 October 1998, and any failure to adhere to the outlined requirements could result in enforcement actions by the Civil Aviation Safety Authority. The directive originated due to several instances of corroded RAT actuators and a case of RAT deployment failure, underscoring the critical importance of adhering to these safety mandates to prevent similar incidents.