COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AD/B747/73 Stabiliser Limit Switch Assembly 11/89
Applicability: All model Boeing 747 series aeroplanes as listed in Boeing Service Bulletin 747-27- 2228 Revision 1 dated 26 October 1984.
Requirement: Action in accordance with Boeing SB 747-27-2228 Revision 1 dated 26 October 1984.
Note: FAA AD 89-15-02 refers.
Compliance: Prior to 2 May 1991.
Background: The FAA have advised that reports have been received that even though the stabilizer controls have been set within safe operating limits, air loading on the horizontal stabilizer can cause the take off warning alarm to sound at speeds approaching V1 during take off when trim is set at the end of the “green band”. This condition, if not corrected could result in unnecessary rejected take offs, and the consequent high potential for aircraft incidents and accidents.
Overview
The Civil Aviation Regulations 1998, which are part of the legislative framework governing civil aviation safety in Australia, include the Airworthiness Directives that ensure aircraft maintain a high standard of airworthiness. One such directive, AD/B747/73, was introduced to address a specific issue with the stabiliser limit switch assembly in Boeing 747 series aeroplanes. The Federal Parliament, through the Civil Aviation Safety Authority (CASA), enacted these regulations to ensure the safety of air travel. The policy objective behind AD/B747/73 is to mitigate the risk of unnecessary rejected takeoffs and potential aircraft incidents or accidents, which could arise from the take-off warning alarm sounding erroneously due to air loading on the horizontal stabiliser. Compliance with this directive was required by 2 May 1991, aligning with the Federal Aviation Administration's corresponding directive, FAA AD 89-15-02.
Scope and Application
The Civil Aviation Safety Authority's Airworthiness Directive AD/B747/73, part of the Civil Aviation Regulations 1998, applies specifically to all Boeing 747 series aeroplanes as detailed in Boeing Service Bulletin 747-27-2228 Revision 1 dated 26 October 1984. This directive is essential for ensuring the continued safe operation of these aircraft by addressing an issue where air loading on the horizontal stabiliser can cause the take-off warning alarm to activate under certain conditions. The requirement outlined in the directive necessitates action in accordance with the referenced Boeing Service Bulletin. The directive mandates compliance before 2 May 1991, ensuring that all relevant aircraft meet the specified safety standards to prevent unnecessary rejected take-offs, which could lead to increased risk of incidents and accidents. While the directive itself sets forth the necessary actions, it may be further elaborated or implemented through additional regulatory instruments as needed to ensure compliance and safety within the Australian aviation industry.
Key Provisions
The key provisions of the Civil Aviation Regulations 1998, particularly under Part 39 - 105, involve the Airworthiness Directives for Boeing 747 Series Aeroplanes. Section AD/B747/73 pertains to the Stabiliser Limit Switch Assembly. This directive applies to all Boeing 747 series aeroplanes as specified in Boeing Service Bulletin 747-27-2228 Revision 1 dated 26 October 1984. The directive requires operators to take specific action in accordance with the Boeing Service Bulletin mentioned, which addresses the issue of the take-off warning alarm sounding erroneously due to air loading on the horizontal stabiliser.
The obligations imposed on the parties governed by this directive include ensuring that all model Boeing 747 series aeroplanes adhere to the requirements outlined in Boeing Service Bulletin 747-27-2228 Revision 1. This involves implementing the specified modifications or checks to prevent the erroneous activation of the take-off warning alarm. Operators must comply with the directive and ensure that the necessary actions are completed prior to the compliance deadline of 2 May 1991.
Failure to comply with the requirements set forth in this Airworthiness Directive can result in serious consequences. The directive highlights that if the stabiliser limit switch assembly issue is not addressed, there is a high potential for aircraft incidents and accidents due to unnecessary rejected take-offs. The Federal Aviation Administration (FAA) has issued a corresponding Advisory Directive (AD 89-15-02) to emphasise the importance of compliance. While the specific penalties for non-compliance are not detailed in the text, it is clear that non-compliance could lead to safety risks and potential regulatory enforcement actions.