The ThermaWing
ice protection system
In aeronautics, ice protection systems keep atmospheric moisture from accumulating on aircraft surfaces, such as wings, propellers, rotor blades, engine intakes, and environmental control intakes. Ice buildup can change the shape of airfoils a ...
uses a flexible, electrically conductive, graphite foil attached to a wing's
leading edge
The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...
. Once activated the foil heats quickly, melting and then shedding any ice.
Background
In 1998
NASA Glenn
NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a subsidiary facilit ...
initiated the research and development of the Thermawing system for
general aviation
General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation services ...
. Supported by the
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
SBIR (
Small Business Innovative Research
The Small Business Innovation Research (or SBIR) program is a U.S. government funding program, coordinated by the Small Business Administration, intended to help certain small businesses conduct research and development (R&D). Funding takes the f ...
) program Kelly Aerospace Thermal Systems put the system into production. The
FAA
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic m ...
has certified the heater element configuration.
The original launch of the system was on Columbia Aircraft Manufacturing (now
Cessna
Cessna () is an American brand of general aviation aircraft owned by Textron Aviation since 2014, headquartered in Wichita, Kansas. Originally, it was a brand of the Cessna Aircraft Company, an American general aviation aircraft manufacturing c ...
) 350 and 400 airframes. ThermaWing (formerly EVADE) employs 6 heaters, 3 heater control modules, one main electronic controller and one 7500 watt alternator.
Operation
The outer layer of the laminate is made of heat-conducting
polyvinyl chloride. It offers the durability of a
fluoropolymer
A fluoropolymer is a fluorocarbon-based polymer with multiple carbon–fluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. The best known fluoropolymer is polytetrafluoroethylene under the brand name "Teflon ...
. A zoned heater system is controlled by a solid-state processor. The leading edge (the "impingement" area) is kept warm, continually melting ice as it begins to form. The area just aft, the shedding zone, is normally kept below freezing, causing the streaming water to freeze and collect as ice. During a de-ice cycle the voltage is increased, raising the temperature of this aft shedding zone, melting the ice bond and shedding the ice via
aerodynamic
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
force. Once power is removed from the heater, the shedding zone immediately refreezes and resumes collecting ice until the next de-ice cycle. This system takes as little as 1 second per surface and only 33 seconds to deice the entire aircraft using a 60-second cycle.
Once armed, the system is digitally controlled with automatic shedding cycles activating at 41 °F.
See also
*
Icing conditions
In aviation, icing conditions are atmospheric conditions that can lead to the formation of water ice on an aircraft. Ice accretion and accumulation can affect the external surfaces of an aircraft – in which case it is referred to as ''airframe ...
*
Ice protection
In aeronautics, ice protection systems keep atmospheric moisture from accumulating on aircraft surfaces, such as wings, Propeller (aeronautics), propellers, Helicopter rotor, rotor blades, Intake, engine intakes, and Environmental control system ...
References
{{Reflist
External links
Kelly Aerospace company home page
Aircraft ice protection systems