EU Project SENS4ICE Hybrid Ice Detection Architectures Demonstration Results

Abstract

The EU project SENS4ICE (GA no 824253) addresses reliable detection and discrimination of supercooled large droplets (SLD) icing conditions. These conditions are considered as particularly safety-relevant and have been included in airplane certification specifications. A novel hybrid approach for icing detection combines direct sensing (atmospheric conditions / ice accretion) with indirect techniques based on changing aircraft characteristics. The first part of the project was devoted to the development, maturation and icing wind tunnel testing of icing detection technologies, with a focus on Appendix O (of 14 CFR Part 25 and CS-25) icing conditions. The second part of the project was dedicated to flight testing of icing technologies in natural icing conditions including Appendix O. Two flight test campaigns in early 2023 served to test and demonstrate eight of the direct ice detection technologies under development and in addition the hybrid ice detection system including the indirect ice detection system. All detection technologies performed well during the flight demonstration and generally exhibited robust and timely ice detection behaviour. Particularly the hybrid ice detection approach showed the capability to provide both early detection and a continuous monitoring of ice accretion on the aircraft. This is very promising and can allow to assess the effectiveness of ice protection systems and/or ice accretion on unprotected surfaces during flight. One important finding of the flight test campaigns is that for ensuring safety and certification for icing conditions, not only the atmospheric conditions and the local effects on the aircraft like ice shapes have to be considered. It is also crucial to analyse the overall effects on the aircraft including performance and stability aspects, including operational envelopes like stall speed and maximum angle of attack. This outcome may shed a new light on the ways to approach the means for complying with certification requirements. The SENS4ICE project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no 824253 (SENS4ICE).