Electric wheels could save airlines billions of dollars in fuel expenses

Electronic Products ^ | 12/02/2013 | Jeffrey Bausch

[null and void]

A simple solution to an expensive problem

Did you know that, annually speaking, airlines burn through tons upon tons (upon tons) of fuel taxiing from the boarding gate to the runway?

That’s because today’s jet liners have only the main engines they use for propulsion on board. As a result, the added operating expense for traveling this relatively minor distance is about $1.1 billion.

Thanks to modern-day technology, though, there IS a solution: the WheelTug e-taxi system from Borealis Exploration Limited.

Basically, what you’re looking at above is an induction motorized ground propulsion system mounted to the nosewheel of the plane. All things considered, it’s pretty small. It’s less than five inches in diameter and weighs close to 300 pounds. But this tiny piece of technology has a lot of pull to it: the system can produce 6,000 kN of force, way more than what’s necessary to push a 200,000-pound 737 from gate to runway.

"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 in a statement. "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."

Worth noting is that the motor is in no way, shape, or form connected to this plane system. Instead, it’s powered by the aircraft’s auxiliary power unit. This means the plane’s flight crew need only rev up the main engines when ready for takeoff, thereby saving fuel, time, maintenance, and, perhaps most important, money.

"We believe on-board electric motors have a great many advantages," added Bob Carman, Chorus Motors' WheelTug program manager. "They could reduce the need for ground tugs and their associated costs, allow faster flight turnarounds and increased fuel efficiency per trip, and reduce airplane noise and emissions at airports, to name just a few advantages."

The WheelTug e-taxi system is expected to reduce the cost of each aircraft by approximately $500,000 a year, or roughly $700 per flight (no word on whether the airlines will be passing on those savings to the customers in the form of reduced ticket fees and free baggage checks).

Check out the WheelTug system in action in the video below. It’s been in the works for a while now, but the group’s first wheel (designed for the Boeing 737NG) has just entered service with El Al airlines.

[video at source]

Learn more at wheeltug.com

[TexasGator]

“The original poster was correct. Adding 300 pounds will have a significant impact on fuel costs, “

The discussion was on gross weight and reduced fares, not fuel.

[zipper]

300 pounds in passengers/bags or fuel left behind, and about 4 % of 300 pounds per hour in additional fuel costs at 6.5 pounds/gallon.

So a three hour flight would cost 36 pounds of fuel (about 5.5 gallons) plus potential lost revenues from the displaced passengers and bags. Plus maintenance costs on the drive system. And the maintenance costs and fuel costs for running the APU the extra time (normally shut down after engine start).

Jet engines generally have to run at least 3 minutes (sometimes 5 min depending on the engine) before being taken to takeoff power, so for short taxi periods there is no benefit.

I don’t see airplanes pushing back under their own power. They can’t see behind them to turn — a tug with a trained driver is much safer.

In icing conditions (and wet with uphill grades) powered taxi on taxiways using only nosewheel power is completely unworkable, especially when sharp turns are necessary. The taxiways are not cleared of ice or snow with the same priority as the runways. The engines (or some engines) would be required if there were any question.

I assume they already accounted for all this in their 700 dollar savings figure.

Or not.

[TruthInThoughtWordAndDeed]

Not sure about the locked/braked thing. My input on spinning up the wheels came from a WWII pilot I met back in the earl 80s.

[Bidimus1]

They are called CVN’s :)

[dragnet2]

Thanks. I just assumed the gear wheels/tires are turning when exposed to 120++MPH wind.

[Beagle8U]

They would lose 1.5 passengers in capacity every time they left the ground for the life of the plane. That is hundreds a day every day.

If the things screws up and bumps into something, that will cost many thousands.

[Squawk 8888]

No need for extra battery- every aircraft has a generator in the tail that provides hydraulics, electrical power and compressed air (to start the main engines). It uses a lot less fuel than the main engines.

[Squawk 8888]

Cessna makes a business jet that does that to spin up the wheels before landing. Its purpose is to allow landings on gravel runways; spinning the wheels reduces that amount of debris kicked up on touchdown.

[null and void]

Aircraft wheels are not locked or braked during descent.

But, since they are stuck out on the end of the gear, the airflow over the top of the wheel is the same as over the bottom, so it doesn’t tend to spin up the wheel.

If they only stuck out half way, like car tires, I suppose they would spin up in the slipstream.

[Squawk 8888]

That could be at least partly offset by the reduced fuel load.

[MrB]

That would have been my first “downside” question -

over the life of the plane, how much fuel use does the added weight add?

[dinodino]

Fuel costs directly relate to ticket prices.

[dragnet2]

Makes sense...

[American Constitutionalist]

The wheel tug get's it's power from the plane's APU or Axillary power unit.
When you see a airplane ? and it has 2 engines ? or 4 ? there is another engine, well short of right back in the tail of the plane inside the tail cone.
The APU is where the plane get's it most electoral power other than the on board batteries.

[American Constitutionalist]

The jet engines are already started even at the gate or right after they are pulled from the gate.
In this case the engines are left at idle until they get at the end of the run way.

[American Constitutionalist]

Before adding anything onto a plane they need to figure out the weight to benefit ratio.
Adding anything to a plane adds more weight therefore uses more fuel.

[American Constitutionalist]

Your right about the weight penalty and it depends on the actual airfare of those 2 passengers that they lose by the weight penalty.
Figure in that for example it's South West and their airfare for 2 passengers on a route only costs $ 100 so that's $ 200 lost.
They say they can save $ 700 on each flight with this thing so that leaves them with $ 500 each flight after you count in lost of revenue.
I am certain that they would have had Boeing and other companies to look into other ways to shave weight off the plane to accommodate this wheel tug with the weight penalty of this thing on the wheel.
Better yet is the have this built into the wheel some how and be more efficient and less weight.

[US_MilitaryRules]

The reason you smell all the fuel is because the APU’s are running. That smell will still be there.

[Dagnabitt]

Giant plane-pushing women save fuel too.

[null and void]

True, but they are very high maintenance!