AD/B737/68 - Sperry SP300 Autopilot Mode Control Panel

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority, were enacted to provide a comprehensive regulatory framework for civil aviation in Australia. Part 39 of these regulations pertains to the airworthiness of aircraft and includes the Schedule of Airworthiness Directives, which ensure the safety and reliability of specific aircraft models. One such directive, AD/B737/68, addresses a specific safety issue with Boeing 737 Series aeroplanes, particularly those equipped with Sperry SP300 Autopilot Flight Control Computers and Mode Control Panels (MCP). This directive was introduced to rectify reports of uncommanded changes in the MCP altitude window that resulted in unintended altitude changes, thereby enhancing flight safety and compliance with international standards. This particular airworthiness directive was issued to address a problem identified by the Federal Aviation Administration (FAA) regarding the Boeing 737 Series aeroplanes with the specified components. The directive mandates compliance with Boeing Alert Service Bulletin 22A1098, ensuring that modifications are made to the MCP to prevent such uncommanded altitude changes. The policy objective behind this directive is to mitigate safety risks and maintain the airworthiness of the affected aircraft, aligning with the overarching goal of the Civil Aviation Regulations to safeguard public safety and aviation standards.

Scope and Application

The Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, specifically AD/B737/68, pertains to Boeing 737 Series aeroplanes, including models 737-300, -400, and -500, that are equipped with Sperry SP300 Autopilot Flight Control Computers and Mode Control Panels (MCP). The directive mandates compliance with Boeing Alert Service Bulletin 22A1098 and references FAA AD 92-07-09 Amendment 39-8205. The primary objective of this directive is to address and rectify instances of uncommanded changes in the MCP altitude window, which had previously resulted in unintended changes to the aircraft's altitude. To prevent such occurrences, the directive requires modifications to the MCP to ensure it cannot undergo uncommanded altitude changes. Compliance with this directive is mandatory, with an effective date preceding 4 December 1993. The directive applies to specific aircraft models and components, ensuring that they meet the specified safety standards set by CASA and the FAA.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, include the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives for the Boeing 737 series aeroplanes (sections 39-105). One such directive, AD/B737/68, pertains to the Sperry SP300 Autopilot Mode Control Panel (MCP) for the Boeing 737-300, -400, and -500 series aeroplanes equipped with the Sperry SP300 Autopilot Flight Control Computers and Mode Control Panels (MCP). This directive mandates compliance with Boeing Alert Service Bulletin 22A1098 and references FAA AD 92-07-09 Amendment 39-8205. The directive was applicable prior to 4 December 1993 and addresses an issue where there were reports of uncommanded changes in the MCP altitude window, which resulted in changes to the aircraft altitude. The directive requires modification to the MCP to prevent such uncommanded altitude changes. The key obligation imposed by this directive is that the operators of Boeing 737-300, -400, and -500 series aeroplanes with the specified equipment must ensure that the modifications outlined in Boeing Alert Service Bulletin 22A1098 are implemented. This involves making changes to the MCP to prevent uncommanded altitude changes, as reported by the FAA. Compliance with this directive is critical to maintaining the airworthiness of the aircraft, ensuring safety standards are met, and preventing incidents related to altitude changes that are not commanded by the pilot. Failure to comply with this airworthiness directive can result in significant consequences. While specific penalties are not detailed within this directive, non-compliance with CASA airworthiness directives generally can lead to enforcement actions by CASA. These actions can include the imposition of fines, suspension or revocation of air operator certificates, and potential grounding of the aircraft. Additionally, in severe cases, non-compliance could lead to criminal charges if it is found that the failure to comply has caused harm or endangered safety. The potential civil and criminal penalties reflect the importance of adhering to airworthiness directives to ensure the safety and reliability of air travel.