AD/RRT-S/7 - Airflow Control Bleed Valve - Removal of Mod. 5866

Overview

The Civil Aviation Regulations 1998, specifically Part 39, Section 106, addresses the issue of airworthiness directives related to civil aviation safety. Enacted by the Australian Government, these regulations were introduced to ensure that all civil aircraft meet the required safety standards to protect passengers, crew, and the general public. This legislative instrument, F2006B06688, targets a specific issue concerning the Rolls Royce Turbine Engines - Spey Series, particularly the airflow control bleed valve. The policy objective is to mitigate the risks associated with engine accelerations from low power settings, which can lead to power stagnation and excessive turbine gas temperature excursions. The regulation mandates the removal of modification 5866 and requires the installation of modification 6040 to prevent stiction in the bleed valve mechanism, thereby enhancing overall aircraft safety. Compliance with these directives is essential for maintaining the airworthiness of the specified aircraft models, ensuring adherence to the highest safety standards set forth by the Civil Aviation Safety Authority.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, which deals with the Civil Aviation Safety Authority Schedule of Airworthiness Directives, governs the requirements for the airworthiness of Rolls Royce Turbine Engines - Spey Series, including the removal of modification 5866. This directive applies to Rolls Royce engines of specific models, namely 511-5W, 511-8, 511-14, 511-14W, and 555-15/555-15H/555-15N/555/15P, that feature the problematic modification 5866, as identified in Service Bulletin SP 72-916. The directive is designed to ensure that these engines meet safety standards by requiring the installation of Rolls Royce SB No. SP72-964 (Modification 6040) to prevent issues such as power stagnation and excessive turbine gas temperature excursions during engine acceleration from low power settings. Compliance with this directive is mandatory and must be completed before the engine is installed in an aircraft following its next scheduled visit after 30 November 1983. This directive effectively supersedes the previous directive AD/RRT-S/6, which was issued to alert operators about the potential safety issues caused by bleed valve mechanism stiction.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 106, includes an Airworthiness Directive (AD) concerning Rolls Royce Turbine Engines of the Spey Series, specifically AD/RRT-S/7, which mandates the removal of modification 5866 (paragraph 1). This directive applies to the Rolls Royce engines listed in the applicability section, including models 511-5W, 511-8, 511-14, 511-14W, 555-15/555-15H/555-15N/555-15P, provided they feature modification 5866, which is detailed in Service Bulletin (SB) Sp 72-916. The requirement is to implement Rolls Royce Service Bulletin SP72-964, which details modification 6040. This modification must be installed before the engine is placed back into service following its next scheduled maintenance visit after 30th November 1983. Entities governed by these regulations must ensure compliance with AD/RRT-S/7 by incorporating the specified modification 6040 in their maintenance procedures. The compliance timeline is clear: the modification must be installed before the engine returns to service after its next maintenance visit post 30th November 1983. This ensures that any engine featuring modification 5866 is updated to prevent issues such as power stagnation and excessive turbine gas temperature (TGT) excursions, which can occur during engine accelerations from low power settings. By adhering to this directive, operators safeguard the operational integrity and safety of the aircraft. Failure to comply with the AD/RRT-S/7 could lead to serious consequences. The regulations do not explicitly state penalties within the directive, but non-compliance with Civil Aviation Regulations generally could result in enforcement actions by the Civil Aviation Safety Authority (CASA). These actions could include fines, suspension of airworthiness certificates, or other regulatory sanctions. The severity of the penalty would depend on the nature and extent of the non-compliance, but the overarching goal is to ensure that all aircraft meet the necessary safety standards to protect passengers, crew, and the general public.