AD/LTS/11 - Engine Electronic Overspeed Protection System

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Parliament, address gaps in ensuring the safety of civil aviation by imposing stringent regulations on aircraft and their operation. A notable legislative instrument within this framework is the AlliedSignal (Lycoming) Turbine Engines - LTS 101 Series AD/LTS/11 Engine Electronic Overspeed Protection System, which was introduced to address specific safety concerns associated with the engine electronic overspeed protection system of certain AlliedSignal (Lycoming) LTS 101 series engines. This instrument was issued by the Civil Aviation Safety Authority (CASA) to ensure compliance with safety standards, specifically targeting engines that might be at risk due to a manufacturing error affecting the sensor polarity of the magnetic speed pickup. The policy objective behind this directive is to prevent potential engine failures that could compromise flight safety, thereby protecting both the aircraft and its occupants.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, addresses the safety directives related to AlliedSignal (formerly Textron Lycoming) LTS101 series turbine engines installed in certain helicopter models. This directive applies to engines of the LTS101-650B1, -750B1, -650C3/3A, and -750C1 series, which were produced before 9 May 1995 or retrofitted with specific service bulletins prior to that date. The directive mandates that these engines must either replace the magnetic speed pickup with a serviceable one or inspect the pickup to confirm its correct polarity, ensuring the engine's electronic overspeed protection system functions correctly. The directive is applicable to operators of Messerschmitt-Bolkow-Blohm BK117 and Bell Helicopter Textron 222 series helicopters equipped with the specified engine models. Compliance is required within 100 hours of service from 9 June 1995, before further flight, and prior to installation on an engine. This regulation is part of the broader framework of the Civil Aviation Regulations, enforcing safety standards within the Australian aviation industry.

Key Provisions

The Civil Aviation Regulations 1998 (Part 39 - 106) establish specific airworthiness directives for particular aircraft engines, with AlliedSignal (Lycoming) Turbine Engines LTS 101 Series being the focus here (section 1). This directive, AD/LTS/11, pertains to the engine electronic overspeed protection system of certain LTS101 series engines produced or retrofitted before a specified date. The regulation requires either the replacement or inspection of the magnetic speed pickup component (section 2). Specifically, the magnetic speed pickup, part number 4-301-356-01, must be replaced with a serviceable speed pickup in accordance with AlliedSignal Engines Service Bulletin LTS101-73-10-0169 dated 12 December 1994, or inspected to determine correct polarity following the same service bulletin. If the inspection reveals incorrect polarity, the component must be replaced (section 3). Additionally, any uninstalled magnetic speed pickups PN 4-301-356-01 must be inspected in line with the specified service bulletin (section 4). The Civil Aviation Regulations 1998 impose certain obligations on the parties involved, particularly those who operate or maintain the affected engines. Operators and maintenance personnel must ensure compliance with the directive by performing the necessary inspections and replacements within specific timeframes. The requirement to complete these actions within 100 hours of time in service from 9 June 1995, before further flight, and prior to installation on an engine underscores the urgency and importance of adhering to the directive (section 5). Non-compliance could potentially result in safety risks, as the directive aims to rectify a manufacturing error that could otherwise lead to the engine electronic overspeed protection system failing to function correctly. Failure to comply with the provisions set out in the Civil Aviation Regulations 1998 may result in significant consequences. While the specific regulatory text does not detail civil or criminal penalties, non-compliance with airworthiness directives generally can lead to enforcement actions by the Civil Aviation Safety Authority (CASA). Such actions could include fines, suspension or revocation of aircraft operating certificates, or other administrative measures. The potential for severe repercussions underscores the importance of adhering to the directive to ensure continued airworthiness and safety.