WheelTug was founded in 2005 to develop and commercialise a new technology: Electric Taxi. This unique technology used patented, high-power electric motors integrated inside the wheels to drive full-size commercial aircraft on the ground. This all-electric drive system would eliminate the need for engine thrust during taxi and return aircraft control during pushback to the pilot. The estimated savings in fuel, emissions, and engine wear, along with the improvements in turnaround time and personnel safety made a very compelling business case.
After several years of development and on-aircraft tests, WheelTug was ready in 2011 to go live with their first drive motor built into the aircraft wheel envelope.
Installing high-power electric motors inside the wheels of a Boeing 737 is no trivial task. Their analysis determined that gearing, as opposed to direct drive, would give the optimal power solution.
WheelTug needed a partner that could create and manufacture a unique, one-off gear design for the debut of a wholly new application. WheelTug needed someone with both aerospace experience and who also understood the demanding environment inside the aircraft. As the full system needed to be tightly integrated, WheelTug wanted their gearing partner to be a full member of the design team; working with them every step of the way to build a solution that met rigorous performance standards. WheelTug evaluated a number of candidates, and decided that Gibbs Gears had the expertise, the personnel and the drive to make the demonstration “M1” program a success.
Initial contact came about through a personal friendship between WheelTug’s CEO, Isaiah Cox, and Gibbs Gears’ sales manager, Phillip Maurice. However, it was a subsequent tour of the facilities at Stoke Mandeville, Buckinghamshire and some background research which cemented the deal.
“Not only is their facility and capability very impressive, but this company has over 60 years’ experience in cut gears, is very competent technically and is accredited to ISO9001 and AS9100 – search for an aerospace rated gearing company in the UK and Gibbs Gears is top of the list,” says Cox. “Their reputation for quality and precision makes them an ideal partner for WheelTug system development on the Boeing 737NG and further aircraft types.”
Gibbs Gears’ brief for the M1 prototype development was to design and manufacture a gearbox in conjunction with the other team members that would be working within the wheel space envelope. The M1 models we developed were not flight ready variants but were to be used for further testing and development. That said, aviation grade materials were used throughout in the manufacture the gearing elements.
WheelTug’s design and manufacturing team comprised of several companies, spread across the globe, all collaborating together. It was essential that each stage of the M1 design work was well-coordinated among the partners, so each stakeholder in the M1 system knew when design changes were being made, and understood why.
A poorly coordinated subcomponent update can lead to an avalanche of follow-on changes, or untold lost time in reversions. It was important to avoid surprises: so good communication was the key to taking the system from an innovative concept through design to the built product.