UTC Aerospace Systems has licensed a carbon nanotube-based heater technology that it believes could be ready as an electrothermal ice protection system for aircraft within three or four years, the company says.

UTAS licensed the technology from Metis Design Corp, which developed the CNT-based heater with the Massachusetts Institute of Technology’s department of aeronautics and astronautics.

In a field with several existing technologies, including “weeping wing” freezing point depressors and hot gases or compressed air extracted from engines, CNT-based heaters hold the promise to more efficiently prevent ice formation and shed ice across a broad range of applications, including wing leading edges, stabilisers, engine lips and vanes and nose cones, says Chris Wilson, UTAS' senior director of engineering for safety systems.

“The technology will be a strategic enabler as aircraft transition to more electric designs,” Wilson says.

Countering ice build-up on aircraft structures has grown in complexity as aircraft designers pursue ever-thinner wings optimised for laminar flow. In the past, Mike Bair, Boeing’s original 787 programme manager, has said the Dreamliner's composite wing produced a leading edge too thin to accommodate a traditional pneumatic de-icing system, forcing the company to switch to an electrothermal technology. Moreover, Honda Aircraft certificated the HondaJet in December 2015, but needed an extra 11 months to certificate a de-icing system for the aircraft natural laminar flow wings.

With the license in hand, UTAS will now work with manufacturers and regulators to develop the carbon nanotube-based technology into a commercial product suitable for unmanned air vehicles, business jets, rotorcraft and commercial airlines, Wilson says.

By design, CNTs can be integrated into any material – composite or metallic – used to form structures, such as the wing leading edge or the rotor blades of a helicopter, UTAS says. Unlike technologies available today, these vertically embedded CNT heater arrays can vary temperatures as necessary over specific regions of the structure.

"The CNT material has low thermal inertial and excellent heat distribution allowing tailoring of specific heating zones,” Wilson says. “This flexibility allows us to design the heating layers to deliver heat where it is most needed and to optimise for the energy capabilities of the aircraft.”

UTAS plans to develop initial versions of the ice protection systems with carbon nanotube heater arrays for a series of demonstrations over the next two years. Certification and introduction into service could follow within one or two years later, Wilson says.

UPDATE: Article updated with name and title of UTAS official.

Source: Cirium Dashboard