Flight tests, ice detection systems, ice protection systems, ice sensor, icephobic
Ice accretion poses a major threat to the operation and safety of military aircraft (manned and unmanned) and ships operating in cold and humid environments. Under the RTG AVT-299 (Jan. 2018 Dec. 2020), various ice detection and ice protection (anti-icing and de-icing) systems and technologies are being evaluated to mitigate icing risk to allow the military air and sea vehicles to remain at the first degree of operational readiness in all weather conditions. Icing sensors and icephobic coatings are among the solutions that are being proposed as effective and affordable ice detection and ice protection systems, respectively, for military air and sea vehicles. Several member nations of the AVT-299 are currently developing novel icing sensors for better ice detection and formulating various coating materials to prevent ice build up. The effectiveness of these sensors and coatings is typically evaluated in laboratory experiments and through icing wind tunnel testing. However, there are strong needs for the assessment of these technologies on actual aircraft and ships operating in real icing environments to demonstrate their effectiveness and qualify them for real applications.
The Spanish National Institute for Aerospace Technology (INTA), a participating member of the AVT 299, operates CASA C-212 aircraft, equipped with a complete meteorological instrumentation dedicated to carry out a wide variety of in-flight experiments. Every year, INTA conducts two in-flight icing campaigns and these aircraft have been used in several icing studies, including evaluation of the effectiveness of anti-icing and de-icing systems: e.g. Eurice (1997-1999), Extice (2009-2013), Tecoagua (2014-2015), Meteorisk (2015-2017, and 2016-2017), Eufar (2001-present) and Phobic2ice (2016-2019). Within the European Community (EC) Phobic2ice project, INTA has developed a new testing configuration and methodology. The new configuration allows evaluating ice accretion on eight different coatings simultaneously during flights-through-icing conditions. The behaviour of the different coating materials is video recorded, and correlated with the meteorological data monitored in real time.
To complement the ongoing efforts of AVT-299, a number of the RTG participating nations/organizations have expressed interest in leveraging INTA’s yearly icing flight test campaigns, through a Cooperative Demonstration of Technology (CDT) AVT activity, to demonstrate the effectiveness of their respective icing sensors and icephobic coating technologies in the field, under natural icing environments. To this end, the RTG AVT-299 team is proposing a CDT activity leveraging either the fall 2019 or the winter 2020 flight test campaign that will be conducted by INTA. The CDT will run in parallel with the AVT 299 for two years with a target start date of January 2019 and a target end date of December 2020.
The main objective of the proposed CDT activity is to use flight testing to cooperatively evaluate and compare the performance of ice protection systems (IPS) and ice detection systems (IDS) for application to military aircraft (manned and unmanned) and also to military sea vehicles operating in cold and humid environments. The IPS and IDS to be evaluated consist of icephobic coatings and ice detection sensors that will be selected by the CDT technical team members. The flight tests will be conducted using the experimental INTA’s aircraft, C-212, with a configuration developed during a European-Canadian research project (PHOBIC2ICE) for icephobic coatings assessment. This method consists in placing the test samples, with symmetrical profiles and coated with different icephobic surfaces, in a hatch located over the cockpit of the C-212 to expose them to atmospheric icing conditions while flying. In these campaigns, military personnel, experienced in the subject, will dive in areas susceptible of ice accretion. Ice sensors will also be integrated to the configuration to simultaneously evaluate their performance for ice detection. The atmospheric icing conditions will be monitored by the equipment available on the aircraft for correlation studies and comparison purposes.
The coatings and sensors to be tested have been developed in the respective participating nations by highly experienced research groups in the field. These coatings and sensors have been previously validated through laboratory experiments and tests in icing wind tunnels. Therefore, this activity is intended to complement the RTG AVT-299 effort and provide an opportunity for the members of the group to verify the effectiveness of their ice protection (icephobic coatings) and ice detection (ice sensors) technologies under natural icing conditions experienced by a flight test aircraft.
The flight tests to be conducted during this proposed CDT activity are expected to achieve the following:
• Collaboration outcomes
- Increased collaboration between the member nations of the RTG AVT-299 activity
- Effective leveraging of the technical capabilities and facilities of the member nations of AVT-299
- Effective leveraging of the expertise and experience of the technical team members of AVT-299 and other scientific and technical experts of the member nations
• Scientific outcomes
- Establishment of a flight testing method/procedure for efficient evaluation and demonstration of existing and emerging ice detection and ice protection technologies
- In-flight assessment and demonstration the performance of the icephobic coating technology for ice protection in atmospheric icing environments
- In-flight assessment and demonstration of the ice sensor technology for effective ice detection in atmospheric icing environments