What's Driving WheelTug PLC?

Wheeltug PLC may be onto something with their integrated electric tow-motor concept. Rather than towing airplanes to and from the runway with giant towmotor tugs, per Virgin Airlines recent initiative, Wheeltug's concept has light-weight electric motors embedded within the aircraft wheels. Being reversible, they can eliminate tow-tugs from the pushback equation and save on fuel during those long queues enroute to and from the runway. Delta Airlines is looking for installation of the system on its 737NG fleet by late 2009. Apart from the savings on fuel and engine hours, Wheeltug claims that the overall emissions from aircraft could be cut back significantly. Working on a figure of 5,796,274 airliner flights per year, Wheeltug claims a nationwide fuel saving of 320 million gallons per year. Built into the hubs of the nose wheels, Wheeltug would give aircraft of all sizes full ground mobility (forward & reverse with steering) without turbine propulsion or external tugs. Incorporation of the system will not require airframe modifications. Power is provided by the Auxiliary Power Unit (APU) which, while technically a turbine, is designed for on-ground use. It's also claimed that foreign object damage (FOD ingestion) and hazards to ground-crews would be eliminated by not running jet engines on ramps. Whether or not the FAA will insist upon engine-starting fire protection being provided in the vicinity of runway holding points remains to be seen. Wheeltug's electric drive will be provided by the high torque range of Chorus Meshcon Motors. The concept was first demonstrated on an Air Canada 767 by Boeing Phantom Works in June 2005 at loads of up to 94 percent of the maximum takeoff weight.