AD/B727/123 - Landing Gear Selector Valve Actuator Arm

Overview

The Civil Aviation Regulations 1998, particularly Part 39, establish comprehensive safety standards and procedures for civil aviation in Australia. One such regulation is the Airworthiness Directive AD/B727/123, which was enacted to address the specific safety concern of the Boeing 727 series aeroplanes' landing gear selector valve actuator arm. This directive was introduced to mitigate the risk of an all wheels-up landing, which can occur if a nut is missing from the landing gear control selector valve actuator arm installation. The Australian Parliament, through the Civil Aviation Safety Authority, issued this directive to ensure compliance with safety standards, reflecting the policy objective of enhancing aviation safety by requiring modifications as specified in Boeing Service Bulletin 727-32-0372 or its revision. The directive mandates that the specified modification be carried out unless it has already been completed, and compliance is required by 31 March 1992. This legislative measure aligns with the broader goal of maintaining high safety standards within the Australian civil aviation sector, thereby protecting passengers, crew, and the general public from potential hazards associated with aircraft malfunctions. The directive references FAA AD 90-02-08 Amendment 39-6470, indicating a coordinated effort with international aviation authorities to address this critical safety issue.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, which deals with the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to Boeing 727 series aeroplanes. This legislation mandates that the selector valve actuator arm must be modified in compliance with Boeing Service Bulletin 727-32-0372 or its Revision 2 to prevent incidents such as the reported all wheels-up landing, which was attributed to a missing nut from the landing gear control selector valve actuator arm. The requirement necessitates that these modifications be completed before 31 March 1992, as referenced in FAA AD 90-02-08 Amendment 39-6470. This regulation applies to all entities and persons operating Boeing 727 series aircraft within Australia, ensuring adherence to national and international aviation safety standards.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, contains an Airworthiness Directive (AD) relating to the Boeing 727 series aeroplanes, known as AD/B727/123 (1). This AD focuses on the landing gear selector valve actuator arm and mandates that the selector valve actuator arm must be modified in accordance with Boeing Service Bulletin 727-32-0372, or Revision 2 of Service Bulletin 727-32-0372 (2). This directive applies to all models in the 727 series (3). The modification must be completed unless it has already been accomplished (4). The AD imposes specific obligations on the parties and entities it governs. Primarily, operators of Boeing 727 series aircraft are required to ensure that the selector valve actuator arm is modified as specified in the referenced Boeing Service Bulletins (5). This requirement ensures that the risk of an all wheels-up landing, which was reported due to a missing nut from the landing gear control selector valve actuator arm, is mitigated (6). Operators must ensure that this modification is carried out prior to the compliance deadline of 31 March 1992 (7). Failure to comply with the requirements of AD/B727/123 may result in serious safety implications, as the directive was issued in response to a significant incident (8). While the specific offences, penalties, or consequences for non-compliance are not detailed in the extract, it is implied that failure to adhere to the AD could result in regulatory action under the Civil Aviation Act 1988 or the Civil Aviation Regulations 1998 (9). Non-compliance with airworthiness directives is generally considered a breach of the operator's licence conditions, potentially leading to enforcement actions by the Civil Aviation Safety Authority (CASA) (10). Such actions could include fines, suspension, or revocation of the operator’s licence, thereby impacting the ability to legally operate the aircraft.