AD/TPE 331/26 Amdt 1 - Installation of Direct Drive Fuel Control

Overview

The Civil Aviation Regulations 1998, under Part 39, specifically address the issue of ensuring the airworthiness of aircraft engines through Airworthiness Directives (ADs). This particular AD, F2006B07435, pertains to AlliedSignal (Garrett/AiResearch) Turbine Engines of the TPE 331 Series, and was enacted to address safety concerns related to fuel control drive trains in these engines. The AD was issued by the Civil Aviation Safety Authority (CASA) to mandate modifications aimed at preventing engine overspeed issues, thereby enhancing flight safety. The policy objective is to align with international standards and ensure that engines meet safety requirements through the installation of a modified fuel control drive train, as stipulated in the FAA AD 78-25-08 Revision 3. The re-issued AD, effective from 12 January 1992, aligns CASA’s requirements with the Federal Aviation Administration (FAA), and removes the mandatory requirement to fit a modified torque sensor.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, pertains to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, which mandates specific requirements for the maintenance and operation of certain aircraft engines. This legislation applies to the AlliedSignal (Garrett/AiResearch) Turbine Engines of the TPE 331 Series, including models TSE 331-3 and TPE 331-1, -2, -3, -5, and -6 as listed in Garrett Service Bulletin TPE 331-72-0061 Revision 5. The directive requires the installation of a modified engine fuel control drive train in the main reduction gearbox, in accordance with FAA AD 78-25-08 Revision 3 Amendment 39-3787, as referenced in Garrett Service Bulletin TPE 331-72-0061 Revision 5. Notably, engines modified in line with previous issues of this directive or with AD/AIR-T/35 Amendment 3 do not need further modification. The directive's compliance date was initially set for 31 December 1985, with this reissue effective from 12 January 1992. The directive originated in response to N2 overspeed protection issues in Australia, aiming to enhance safety by implementing specific modifications to the engine's fuel control drive train.

Key Provisions

The primary sections of the Civil Aviation Regulations 1998, Part 39 - 106, as it applies to the AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series, are set out in the Airworthiness Directive AD/TPE 331/26 Amendment 1 (sections 1-4). This directive specifies the applicability of the directive to certain TPE 331 series engines and mandates the incorporation of a modified engine fuel control drive train in the main reduction gearbox in accordance with FAA AD 78-25-08 Revision 3 Amendment 39-3787 (section 2). Equipment that has been modified in compliance with previous issues of this directive or with AD/AIR-T/35 Amendment 3 does not require further rework (section 3). The compliance date for the original issue of this directive was 31 December 1985, with this re-issue effective from 12 January 1992 (section 4). The obligations imposed by this directive include ensuring that the specified TPE 331 series engines are fitted with the modified engine fuel control drive train as described. This requirement is applicable to TSE 331-3 and TPE 331-1, -2, -3, -5 and -6 series engines, as listed by model and part number in Garrett Service Bulletin TPE 331-72-0061 Revision 5. Furthermore, the directive explicitly notes that engines modified in accordance with previous versions of this directive, or with AD/AIR-T/35 Amendment 3, do not need further modification. In the event of non-compliance with the Airworthiness Directive AD/TPE 331/26 Amendment 1, the consequences can be severe. While the specific penalties are not detailed within the text, the overarching legislation under which these regulations operate can impose significant fines and penalties for non-compliance with airworthiness directives. The severity of the penalties typically depends on the nature and extent of the non-compliance, and could potentially include both civil and criminal consequences. Given the critical nature of aircraft safety, breaches of airworthiness directives are taken very seriously, and can result in substantial financial penalties, as well as potential criminal charges against the responsible parties.