AIAC-13 Thirteenth Australian International Aerospace Congress Sixth DSTO International Conference on Health & Usage Monitoring Towards Wireless Sensor Usage and Health Monitoring of Helicopter Rotor Components N.A.J. Lieven 1 , P.J. Escamilla-Ambrosio 2 , P. Bunniss 1 , S.G. Burrow 1 and L.R. Clare 1 1 Department of Aerospace Engineering, University of Bristol, University Walk, Bristol, BS8 1TR, United Kingdom 2 Department of Computer Science, University of Bristol, Woodland Road, Bristol, BS8 1UB, United Kingdom Abstract Wireless sensors offer the promise of a paradigm shift from traditional schedule-driven maintenance to condition-based maintenance of aircraft subsystems. In particular this technology will benefit applications where running cables to sensors is difficult or impossible. This is specially the case in rotary-wing aircraft. This work reports research carried out under the umbrella of the Wireless Intelligent Sensor Devices programme, supported by the UK Technology Strategy Board, to advance the development of the hardware and software required to continuously in-flight monitor the wear rate within the pitch link end bearings and fitting of the Lynx Helicopter. This shall greatly enhance the operational readiness and cost effectiveness of the helicopter. Results of this research are reported in three areas: 1) development of low power sensing interface and signal conditioning, 2) pitch link test carried out to aid the development of feature extraction and wear detection algorithms and 3) intelligent feature extraction algorithms, wear detection and results. Keywords: Wireless intelligent sensor, rotor-head health monitoring, low-power signal conditioning, feature extraction, critical wear detection. Introduction One of the long-term objectives of the aviation industry has been the continuous monitoring of the health of aircraft subsystems in order to identify early problems before they affect the airworthiness of the aircraft. The current way of addressing the health monitoring problem is by calendar-based or usage based scheduled inspection and maintenance of damage-sensitive parts and, if required, replacement of such parts [1]. These practices are time-consuming and labour-intensive, which make them expensive. Wireless sensor offer the promise of a paradigm shift from traditional schedule-driven maintenance to condition-based maintenance of aircraft subsystems. In particular this technology will benefit applications where running cables to sensors is difficult or impossible. This is the case with rotating components of which there are many examples in the aerospace industry and, specially, in rotary-wing aircraft. Wireless intelligent sensors could potentially be permanently placed in critical rotating components to monitor their state of health without human intervention. Algorithms running on-board the wireless sensor processor could perform feature extraction and pattern recognition algorithms to determine the level of wear of a component and estimate its remaining useful life, transmitting results only when maintenance or inspection is required. This offers the potential to lower operating costs and enhance flight reliability. However,