FUEL COSTS are an airline’s worst enemy. Over the past fifteen years rising global demand and political unrest at main suppliers have seen the commodity jump to an average of 40% of an carrier’s overall costs. That fact is concerning since fuel is a volatile cost, prone to sharp rises and falls in price over short periods of time, making even the soundest of budgets unreliable. Thus efforts to curb this risk are growing, the latest product of these efforts is the ability to taxi without using engines or a tug.
WheelTug, a subsidiary of Chorus Motors, has developed a small but powerful electric motor installed in the nose-gear that draws energy from the APU. Able to provide enough torque to get an aircraft moving, it can also taxi at standard speeds with a full passenger load. The company successfully trialled the system on a Boeing 737-700 this summer, as can been seen here.
WheelTug claim that savings on a Boeing 737-800 of roughly 95,000 gallons, or by accountants estimates; $500,000 per year. They go on to mention other advantages; reduced engine wear, environmental benefits and less dependability on airport staff (no need for pushback tugs).
With merits come detriments. The WheelTug device adds approximately 300lbs to overall weight, which over the course of an entire flight results in higher fuel burn and hence reduced range. And while engine maintenance will be reduced, the device itself will bring its own reliability issues to airline operations.
WheelTug are not alone in the engine-less taxi field, hot on their heels are Messier-Bugatti who are working closely with Airbus to incorporate their taxi system into the main landing gear of the A320neo. Unlike WheelTug, Messier-Bugatti benefit from established relationships in the industry, having designed numerous landing gear components for both Boeing and Airbus.
Whilst very much in its infancy, this technology shows the most promise since the advent of blended winglets, now a common sight on Boeing aircraft and soon to be introduced on the A320 family. As was the case with winglet technology, engine-less taxiing has a great chance of being the next major trend to be adopted by airlines worldwide.