Overview
When an aircraft flies in cold, moist air, especially at low altitudes, ice can form rapidly both on and behind the leading edge of aerofoils and other structures. The growth of the ice disturbs the local airflow and can radically alter the lift of the aerofoil and hence the handling characteristics of the aircraft. This phenomenon has caused a number of fatal accidents and loss of control events and is a problem that will intensify as increased pressures on airports mean that aircraft will spend much longer in low altitude holding patterns.
Large aircraft use hot-gases diverted from the engines to remove ice from flight-critical surfaces, while smaller aircraft sometimes use pneumatic boots which expand under pressure to shed the ice layers. These technologies are incompatible with future generations of air transport, in which composite materials will be used extensively. Furthermore, current ice detectors are insensitive, cannot distinguish between ice types and are not co-located with the safety critical zones.
Building on electro-thermal de-icing technology now widely used in helicopters, the objective of the ON-WINGS project is to develop a smart, autonomous, composite electro-thermal de-icing system for fixed wing, helicopter rotor blade and engine inlet applications. The system will incorporate, for the first time, ice detection sensors integrated within the structure, capable of reliably detecting the presence, thickness and type of ice including SLD and mixed phase ice - accreted on the surface. The sensors will control the operation of the electro-thermal heater blankets, thus ensuring optimum de-icing performance while minimising power demand.
The system, which will include a self-diagnostic capability, will be validated in an extensive series of icing tunnel trials. ON-WINGS brings together the major European aircraft and helicopter manufacturers, specialist SME's and research institutes to work on a critical safety issue which crosses national and company boundaries.
Funding
Results
At the moment (early February 2013) results have not yet been published. The following results therefore reflect preliminary results. The resulting system will incorporate the following:
- a primary 'on-wing' ice detector for activation of the ice-protection system;
- a 'smart' electro-thermal de-icing system: this is to demonstrate the interaction and control of electro-thermal heater elements and an integral aero-conformal ice detection and distributive temperature/health monitoring system;
- air conformal optical ice detectors for primary activation of the ice-protection system;
- novel concepts based on sophisticated fibre-optic methods capable of measuring ice distributed over large areas.
A complete smart air conformal ice-detection system will be demonstrated, capable of detecting the ice thickness and roughness for critical aerospace applications.
Innovation aspects
Development of a smart, autonomous, composite electro-thermal de-icing system that incorporates ice detection sensors integrated within the structure.
Strategy targets
Innovating for the future (technology and behaviour): A European Transport Research and Innovation Policy