AD/TB10/4 - Wing Flap Deflection - Modification

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority, were enacted to ensure the safety of civil aviation in Australia. This legislation, which forms part of the broader regulatory framework governing the operation of aircraft, includes specific directives to maintain the airworthiness of aircraft types. Among these is the AD/TB10/4 for the Aerospatiale (Socata) TB9 and TB10 (Tobago) series aeroplanes, which was introduced to address issues concerning wing flap deflection and the associated stability and control parameters of these aircraft. The objective of this directive is to modify the wing flap deflection to ensure adequate longitudinal stability when the flaps are fully extended. This is achieved by reducing the maximum flap extension from 32 degrees to 25 degrees 30 minutes, and adjusting the forward centre of gravity limit to 11% of the mean aerodynamic chord, or 0.949 metres. The modifications necessitate corresponding updates to the aircraft flight manuals, requiring the incorporation of amendment 4 and the removal of amendment 3. Compliance with these directives is mandatory before re-certification of the aircraft, ensuring that all affected aircraft meet the required safety standards.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 – 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, mandates modifications to the wing flap deflection for Aerospatiale (Socata) TB9 and TB10 (Tobago) series aeroplanes. This regulation applies to all TB10 aircraft from serial number 1 up to and including serial number 239. The directive necessitates compliance before certification, ensuring that aircraft flight manuals incorporate amendment 4 while removing the contents of amendment 3. This modification is aimed at maintaining adequate longitudinal stability by reducing the maximum flap extension from 32 degrees to 25 degrees 30 minutes, and also adjusts the forward centre of gravity limit to 11% of the mean aerodynamic chord or 0.949 metres. The directive extends to ensuring that the modifications are incorporated prior to the certification of the aircraft, which is critical for maintaining safety standards in civil aviation within the Commonwealth of Australia.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, contain the Airworthiness Directive (AD) AD/TB10/4 which mandates modifications to the wing flap deflection of the Aerospatiale (Socata) TB9 and TB10 (Tobago) series aeroplanes. This directive applies to all TB10 aircraft with serial numbers ranging from 1 up to and including 239 (Section 5/82). The modification is documented in the Rallye TB SB No. 10 GR.27.17, which includes an amendment to the aircraft flight manuals. Specifically, amendment 4 must be incorporated, while the contents of amendment 3 must be removed. The AD imposes several obligations on the parties or entities it governs. Firstly, any modifications to the wing flap deflection must be completed before the aircraft is certified as airworthy. This ensures that the aircraft maintains adequate longitudinal stability, especially with full flap extension. The modification reduces the maximum flap extension from 32 degrees to 25 degrees 30 minutes, and also adjusts the forward centre of gravity (C.G.) limit to 11% of the mean aerodynamic chord (M.A.C.) or 0.949 meters. These modifications are critical to ensuring the safety and compliance of the aircraft in accordance with the regulations. The Civil Aviation Regulations 1998 also outline potential consequences for non-compliance with the AD. While the specific section of the Act pertaining to penalties is not detailed in the provided text, it is standard practice under the Civil Aviation Act 1988 for breaches of airworthiness directives to be subject to civil or criminal penalties. Failure to adhere to these directives can lead to fines, imprisonment, or both, depending on the severity of the breach and its impact on aviation safety. The maximum penalties can be severe, reflecting the critical nature of ensuring aircraft safety and compliance with airworthiness standards. In summary, AD/TB10/4 requires the modification of wing flap deflection for specified TB10 aircraft to maintain adequate longitudinal stability. This directive must be complied with before the aircraft can be certified, and failure to do so can result in significant legal and financial consequences under the Civil Aviation Act 1988. The modifications, including the incorporation of amendment 4 and the removal of amendment 3 from the aircraft flight manuals, are essential to maintaining the safety and airworthiness of the aircraft in question.