AD/F28/70 Amdt 1 - Horizontal Stabilizer Actuator Servo Valve Assembly

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, represent a comprehensive framework governing civil aviation safety within the country. One particular legislative instrument under this act, F2006B09804, specifically addresses the safety concerns of Fokker F28 Series Aeroplanes through Airworthiness Directives. This legislative instrument was introduced to address the identified problem of horizontal stabilizer malfunctions in Fokker F28 aircraft, which can lead to dangerous flight conditions. The policy objective of this directive is to ensure the continued airworthiness and safety of these aircraft by mandating specific modifications to the horizontal stabilizer actuator servo valve assembly, as outlined in the Fokker Service Bulletin SB F28/27-183. Compliance with this directive is critical to prevent incidents where the stabilizer trim could inadvertently move to unsafe positions, as evidenced by an incident where a F28 climbed uncontrollably to 31,000 feet due to such a malfunction.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, concerns the application of Airworthiness Directives (AD) for the Fokker F28 Series Aeroplanes. This legislative instrument applies to all model F28 aircraft serial numbers 11003 through 11241, 11991 and 11992, and all spare Menasco actuators part number 11100. The directive mandates that action must be taken in accordance with Fokker Service Bulletin SB F28/27-183 unless such action has already been completed. Compliance with the directive is critical, with a requirement to adhere to the specific timelines provided for the different parts of the requirement document. Part 1 must be completed by 1 August 1995, while Part 2 must occur at the next removal of the stabilizer control unit or by 1 January 1998, whichever is earlier. The directive also stipulates that the required modifications must be made prior to the installation of the actuator on an aircraft. This AD was prompted by an incident where a horizontal stabilizer malfunction caused an aircraft to climb uncontrollably, highlighting the importance of these safety measures.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives for Fokker F28 Series Aeroplanes, includes Amendment 1 (AD/F28/70) concerning the horizontal stabilizer actuator servo valve assembly, dated 5/95. This amendment applies to all model F28 aeroplanes, excluding Mark 0100, with serial numbers ranging from 11003 to 11241, 11991, and 11992, as well as all spare Menasco actuators with part number 11100. The amendment requires actions to be taken in accordance with Fokker Service Bulletin SB F28/27-183, referencing RLD AD 1992-077/2 (A) and Fokker SB F28/27-183, which in turn refers to Menasco SB 11100-27-105. Compliance with this directive necessitates that specific actions be completed by certain deadlines. For Part 1 of the requirement, the actions must be completed by 1 August 1995. For Part 2, the requirement must be met at the next removal of the stabilizer control unit or by 1 January 1998, whichever comes first. Additionally, any modifications must be done before the installation on an aircraft. This directive was prompted by an incident where an overseas F28 experienced a malfunction in the horizontal stabilizer that led to a hazardous situation, underscoring the necessity for the mandated modifications. The obligations imposed by this legislation are clear and stringent, ensuring that the specified modifications to the horizontal stabilizer actuator servo valve assembly are completed in a timely manner. The directive mandates specific compliance timelines and conditions under which the modifications must be performed, ensuring that all affected aircraft are brought up to the required safety standards. Failure to comply with these requirements can result in serious safety risks, as evidenced by the incident that prompted the directive. Breach of these requirements can lead to various consequences. While the specific penalties or consequences for non-compliance are not detailed within the text, it is implied that failure to adhere to the Civil Aviation Regulations and the directives issued under them can result in significant civil or criminal penalties. Given the safety implications of this directive, non-compliance could potentially lead to enforcement actions by the Civil Aviation Safety Authority, which may include fines, penalties, or other regulatory measures. The exact penalties would be determined based on the severity and impact of the non-compliance, but the overarching aim is to ensure the highest standards of aviation safety are maintained.