Flight tests results of a Fiber Bragg Gratings based ice sensor

Abstract

Icing has been an aeronautical industry problem for safety and for energy consumption save from the beginning of aviation. It affects the safety reducing the lift, decreasing the stall angle of attack, affecting the aircraft stability and reducing the control efficiency. The European project SENS4ICE (2019–2023) introduces a new technology based on hybridization of different detection techniques, combining indirect ice sensing with direct, using atmospheric and ice accretion sensors. In the present work a study about a Fiber Optic Detector based on latent heat that uses a Fiber Bragg Grating for measuring the surface temperature. The Fiber Optic Detector (FOD) was tested in a SAFIRE Flight Testing Platform ATR42 during 40 h of Flight testing, having Liquid Water encounters in all flights. The sensor performance and its ability for measuring the icing severity is evaluated in the paper, showing results in a representative Flight test. During Flight Test, different icing conditions were seen, adapting the detection and severity evaluations to the data seen with other reference atmospheric sensors. For ice detection Discrete Wavelet Transform (DWT) was used using different levels in order to detect all the possible events during the Flight test. The DWT ice severity assessment results were compared with a Messinger Model and with the DLR Nevzorov data in order to evaluate the precision and the sensor performance.