Spirit AeroSystems Developing Nacelle Anti-ice Systems
Taking a proactive approach toward the anti-icing regulations proposed by the FAA in June 2010–and still unscheduled for adoption into the FARs–Spirit AeroSystems (Booth No. C11720) has been working with Wichita State University and an undisclosed supplier to develop two new anti-icing systems for nacelles surrounding large aircraft engines.
Spirit’s electro expulsive de-icing system (EEDS) uses an electromechanical “thumper” to tap the nacelle from the inside to shed ice. Spirit research-and-development manager Daryl Tasker estimates EEDS will weigh less and consume 85 to 95 percent less power than comparable bleed-air de-icing systems.
“Similar types of systems have been implemented on aircraft leading edges and on unmanned aerial vehicles, so this isn’t completely new,” said Tasker. “It’s just new as far as a nacelle application. The nacelle is a lot more intricate. There are surprisingly complex structures and mechanisms involved.”
If adopted as written, the proposed FAA regulations will require airplanes most affected by supercooled large droplet (SLD) icing conditions to meet certain safety standards in the expanded certification icing environment, including additional airplane performance and handling qualities requirements. Currently it’s not clear how much ice airframe and engine induction de-icing systems must remove to comply with the proposed regulations. Because EEDS can leave trace frost behind, Spirit also developed the hybrid ice protection system (HIPS), which adds an electric heating element to the system to melt any residual frost.
“If the system must be completely evaporative to support the SLD requirement from the FAA, then you won’t even be able to have frost,” said Tasker. “[HIPS] incorporates an additional element that applies heat electrically to complement the thumper on EEDS. Some OEMs think they will need [HIPS], some don’t.”
Currently EEDS and HIPS have been tested only in wind tunnels, but Tasker said the program is ready for flight test. No launch customer has yet been identified for either system, and certification is likely at least two years away.
Spun off by Boeing and sold to Onex Corp. in 2005, Wichita-based Spirit AeroSystems is best known for manufacturing large-scale aircraft structures such as wings, fuselages and engine pylons for large business and commercial aircraft. Spirit is currently under contract to build the pylons for the Bombardier CS100 and CS300 jets.