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
Another interesting thing... these wheels are on the nose. Maybe due to weight distribution, having them amidships would allow for better traction.
Neither is the complexity of the added feature. Can you imagine the nosewheel freezing up on touchdown due to a system failure? A motor in the nosewheel creates lots of new problems and complications. I would be curious to know how the wheels behave when NOT in the traction "mode."
lol...
This is like dial an argument...
No thanks~
This is a great idea, whether you like it or not. And not just for taxiing around, but landing too...
See Ya!
Yes, and I remember free wheeling wind turbines as well. Apparently the weight and complexity of those systems didn't 'pencil'.
This might, since that ability is in addition to the primary fuel savings goal and is therefore essentially free, at least for the front wheel.
I like Gaffer's idea. Perhaps the tire replacement savings on the front wheel will drive revisiting doing the same for all wheels?
“Aircraft materials are becoming lighter every year. Aircraft are considerably lighter than they were just 20 years ago.”
At $one million per pound cost over the life of a plane, they better be getting lighter!
The weight of even tiny little parts was so critical that we had scales to weigh things equal to those used by the bureau of standards.
Oh of course you say something lame then blame the one who points it out. I thought that was a liberal game.
Ooooooo! Good point! Think of the See Oh Too emissions reduction!
How might it wear tires any faster than other operations?
If they can spin up the tires before landing that would be an even bigger savings(not claimed yet).
In my case, less than one...
About 20 years ago I asked an aero engineer wht they didn’t add hydraulc motors for taxing and he had no answer.
Make the passengers get out and push the plane. Give them a bag of peanuts or something.
Well, just thinking that other tires generally only have to serve as rollers. These have to dig in and provide traction.
True, but if the runway/tarmac is too sloppy for a wheel with the full weight of a commercial airliner on to to get a grip, I imagine it’s too slippery for a dinky little tractor as well.
I was thinking that the motor in the nosewheel would maybe not be the good idea. Under wet conditions, I bet it would slip because of no tractive force (meaning, “no” weight on it) plus one would rather not have the big weight of the motor on such a critical item, at the end of the landing gear. Better, I think, to have the item as one/two per side on the main landing gear. And maybe it should be a hydraulic motor (but still run by the APU)
Regardless of the exact schema which I’m not qualified to evaluate, the general idea would seem to have serious merit, IMO.
I wonder if the system could be adapted to heavy trucks. Perhaps the heavy transmissions and much of the conventional drive train could be eliminated.
Don’t worry, it’s already been added to your excess baggage fee. ;)
Reasonable logic, but no. The take-off checks bring the power way up on the engines, while the brakes are held and that is where you would expect to see problems. Assuming the engine starts, the very low power settings used for taxiing aren't enough to manifest any problems.
I am a retired airline employee who flies frequently as a standby passenger. I have been unable to get on a number of flights, with empty seats, due to weight restrictions. Usually that means a heavy cargo load aboard so fewer passengers can fly. Non-urgent cargo can be delayed to prevent a revenue passenger from being denied boarding but cargo makes more money than people, and they’re not going to remove cargo to allow a non revenue passenger like me to board.
High temperatures, high airport altitude, shorter runways, and high fuel loads can also cause weight restrictions.
Depending on the size of the airport, the taxi fuel burn for a 737 is normally computed to be 500 lb., so there would still be a weight savings. With a drive like this you would still need APU fuel and start fuel.
The assembly is already pretty robust.
Normal landings slam it into the ground pretty hard as it is.
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