AD/SF340/71 - Engine Control Quadrant - Inspection of Flight Idle Stop Solenoid Bracket Screw

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, aim to ensure the safety and efficiency of civil aviation operations within the country. These regulations, overseen by the Civil Aviation Safety Authority (CASA), are designed to establish comprehensive safety standards and procedures for aircraft operations, maintenance, and certification. One such regulation, specifically targeting the SAAB SF340 Series Aeroplanes, is addressed in Airworthiness Directive AD/SF340/71. This directive was introduced to mitigate the risk of engine control quadrant issues that could potentially lead to operational hazards, such as power lever binding and malfunctions in the Flight Idle Stop. The directive mandates regular inspections and replacements of specific screws within the control quadrant to prevent the identified problems, ensuring the continued airworthiness of affected aircraft. The policy objective behind AD/SF340/71 is to enhance the safety of SAAB SF340 Series Aeroplanes by addressing a specific mechanical issue that could compromise flight operations. By requiring periodic inspections and the replacement of certain components within the engine control quadrant, the directive aims to prevent the occurrence of loose screws that might cause the power levers to bind or malfunction. This proactive measure is essential in maintaining the integrity of the aircraft's control systems and ensuring the safety of all passengers and crew on board. The directive's effective date of 9 September 1999 underscores the urgency and importance of addressing this identified safety concern within the aviation industry.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 – 105, mandates the inspection and maintenance of certain components of the Engine Control Quadrant in SAAB SF340 Series Aeroplanes, affecting operators of these aircraft within Australia and internationally as they must comply with Australian regulations when operating in Australian airspace. The Airworthiness Directive AD/SF340/71 applies to SAAB Model SF340A aircraft serial numbers 004 through 159 and SAAB Model 340B aircraft serial numbers 160 through 459, excluding those Engine Control Quadrants with specific part numbers and reference letters such as 53082 F, 53162 C, 53170 D, and 53210 A. The directive requires the inspection and, if necessary, the replacement of the Flight Idle Stop Solenoid Bracket Screw, with compliance to be achieved within 800 flight hours of the directive's effective date and thereafter every 800 flight hours or within 8000 flight hours or six years from the directive's effective date, whichever is sooner. The directive came into effect on 9 September 1999 following a reported issue with the left-hand power lever binding, which was traced to loose screws within the Control Quadrant assembly.

Key Provisions

The Civil Aviation Regulations 1998, Part 39, Section 105 (referenced as F2006B07001), mandates specific maintenance actions for the Engine Control Quadrants of SAAB SF340 Series Aeroplanes. This directive applies to aircraft serial numbers 004 through 159 for SAAB Model SF340A and 160 through 459 for SAAB Model 340B, excluding certain part numbers and reference letters as listed. The primary requirement outlined in Section 1 of this directive is to inspect two screws within the Engine Control Quadrant as specified in SAAB Service Bulletin SAAB 340-76-043 dated 02 July 1999. Furthermore, if any loose screws are discovered during this inspection, the Engine Control Quadrant must be replaced with a serviceable, modified item. This directive became effective on 9 September 1999, following an incident where an operator reported issues with the left-hand power lever binding and failure to go into reverse after landing, due to a screw backing out of a cam and causing binding within the Control Quadrant. The obligations imposed by this Airworthiness Directive are clear and must be strictly adhered to by all operators of the specified SAAB SF340 Series Aeroplanes. Firstly, the inspection of the two screws must occur within 800 flight hours of the directive's effective date and subsequently every 800 flight hours if no faults are found. Secondly, the inspection must also occur within 8000 flight hours or six years from the effective date of the directive, whichever comes sooner. Should loose screws be identified during the inspection, the replacement of the Engine Control Quadrant with a serviceable, modified item becomes the closing action for this directive. Additionally, this directive references LFV Airworthiness Directive 1-143 dated 02 July 1999, which further details the necessary steps for compliance. Failure to comply with the requirements set forth in this directive can lead to significant consequences. According to Section 3 of the Civil Aviation Regulations 1998, non-compliance may result in various penalties, including civil or criminal sanctions. The specific penalties for breaches of this directive are not explicitly detailed within the text provided, but they can potentially include fines, suspension of airworthiness certificates, and other regulatory actions. It is imperative for operators to ensure strict adherence to these provisions to maintain the safety and airworthiness of the SAAB SF340 Series Aeroplanes.