Posted on 12/05/2013 9:48:36 AM PST by 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
If the spin up the wheel to near runway speed before touchdown they can also eliminate vast amounts of tire wear. Aircraft tires are hella expensive!
Why would it be cheaper?
ping
Eliminating ground tugs, (and their operators) for starters.
The potential problem I see with this would be that in using the main engines for taxiing, I imagine that they are put under enough load so that any maintenance problem that took a few minutes to show itself would do so before the plane left the ground.
I’m wondering about the cost effectiveness of carrying extra battery weight around.
What about warming up the jet engines before takeoff?
I’ll bet you could install some cupped blade wheel rims (like the cooling fins on a 4 cycle engine impeller on the flywheel) and the reverse equivalent of an antilock braking systems that would allow each wheel to be coupled to a ground speed indicator that would allow the wind to spin up the tires, and then the reverse ALB system would kick in and match rotation speeds to landing ground speed.
Better coupling of the power to motion with a wheel vs blowing hot air.
>”Eliminating ground tugs, (and their operators) for starters”<
Unless the airliner has a rear view camera and outside rearview mirrors, they will still need the Tugs.
Contact the Patent Office right now.
The nice thing about a jet engine is if it survives being spooled up and throttled back at the end of the runway, it’s good to go.
In the absence of a bird strike they are much simpler and more reliable than a piston engine. Far fewer parts to go wrong.
Since you can buy that kind of system to install on your pickup truck for less than 50 bucks, I don’t see it as much of a hurdle to get over.
I know decades ago they experimented with spinning up a planes wheels before landing with electric motors to cut down on tire wear, but it eventually was scrapped. Maybe that’s ready for another look see as well...
Flight historical experience would tell us whether that is a place where problems typically get noticed. There could always be a brief test. One thing electric taxiing drives would also do is reduce the pollution quotient at airports. A lot of airports smell like bus depots because of all the jet fuel burning on the ground.
Still not sure that a ground tug system is impractical. If airports have enough of them waiting, then the airplane doesn’t need to carry one around.
No extra Battery weight needed on most Aircraft either the main engines at MIN power or the APU can generate the needed current for far less then the cost top push the aircraft around by direct thrust.
I do not know if the cost of weight vs fuel in taxi mode would break even but I expect it very well could.
Can the use of oversized slingshoots be far off?
It wasn’t clear in the story but assuming the system adds 300 lbs to the empty weight of the aircraft that is huge. That’s nearly 2 paying passengers worth of weight that has to be hauled around all the time, for the life of the aircraft. That’s a LOT of lost revenue.
If it worked.. then a ram air turbine would be easier than Electric maybe ?
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