NORTH PLAINS, OR--(Marketwire - May 3, 2010) - WheelTug Limited said today that it is making rapid progress on development of its built-in electric drive system for aircraft, and that the major engineering issues of the complex project have been resolved. Specifications for the initial WheelTug model, for the Boeing 737NG aircraft, are expected to be completed and available to airlines by the end of the summer.
The patented and proprietary WheelTug® hybrid-electric drive system incorporates high-performance electric motors installed in nose gear wheels of an aircraft, providing full mobility while on the ground, without the use of the aircraft's jet engines or external tugs for both pushback and taxi operations. WheelTug enables aircraft to be electrically driven from the terminal gate to the takeoff runway, and upon landing from runway exit to the gate. The resulting improvements in efficiency, flexibility, fuel savings, and reduced engine Foreign Object Damage (FOD) yield projected savings of more than $500,000 per aircraft per year, plus reductions in CO2 and other greenhouse gas emissions.
"The idea of putting an on-board electric drive system on aircraft is not new, since there are so many clear advantages," Isaiah Cox, WheelTug President and CEO, said. "But until recently there was no electric motor technology with the capability to produce the required high torque for its small size, weight and safety profile to make it possible." He noted that the initial breakthrough was the development of the Chorus® Meshcon motor, which produces unrivaled startup torque in a small, lightweight package and with the known reliability and safety of an AC induction motor.
Two small Chorus motors, just inches wide, will be fitted into an aircraft's twin nose gear wheel hubs and produce enough torque to drive a large aircraft at normal taxi speeds. This capability was demonstrated and proven in tests during 2005 with two Chorus motors attached to the nose gear wheels of a Boeing 767 aircraft, which was driven forward and backward during a test program that included pushback, taxi, and other ground maneuvers. (A video of these tests can be seen on YouTube, at http://snipurl.com/vyeik)
WheelTug has since resolved the remaining primary engineering questions. One widespread concern was that the 737NG aircraft might not have sufficient electrical power from the APU to power the drive motors and the aircraft simultaneously. Tests conducted with development partners in January established that the aircraft has more than adequate power available to run the WheelTug system, even when all other usual on-ground electrical systems are also operating.
The other major engineering concern was how to make the WheelTug system package, including the wheel itself, fit into the existing nose wheel envelope. "Until now, this was widely seen as an enormous, and perhaps insurmountable, problem," notes Mr. Cox.
WheelTug said its engineers have now designed a solution that also achieves five key design requirements:
1. Do not increase the wheel/tire assembly spin-up loads during landing.
2. Avoid changes to existing landing gear major components, such as the piston/axle assembly.
3. Enable aircraft tire changes as quickly and as easily as is done currently.
4. Prevent inadvertent engagement. Unless the aircraft is on the ground, and the pilot has explicitly powered-up the WheelTug system, the motors must not engage with the wheels.
5. Match the motor and wheel speeds before engagement, to eliminate the need for a clutch.
"Industry experts told us it would require years' more work to solve these tough problems," noted Mr. Cox. "But with brilliant performances from our engineers and consultants, we have met every one of these requirements, and have now resolved these critical engineering and design issues in the WheelTug system."
WheelTug is in talks with both airframe manufacturers and airlines regarding development of WheelTug models for additional commercial aircraft types, as well as for military aircraft. The company's risk-sharing partners currently include Co-Operative Industries for the wire harness, Luxell Technology for the cockpit interface, and ICE Corporation for the system controller.
WheelTug Limited is a wholly-owned subsidiary of WheelTug plc, which is in turn a majority-owned subsidiary of Chorus Motors plc (
Contact Information:
For more information:
Isaiah Cox
President
WheelTug plc
410-419-0082
Exec@WheelTug.com
http://www.WheelTug.com