TheShadow

http://www.designnews.com/article/CA...rid=1302801725
Based on a patented ac-induction motor from Chorus Motors, this WheelTug system takes its power from the plane’s APU and directly drives the nose wheel. It’s designed to move regional and larger aircraft on the ground at speeds up to 20 mph without running their turbines or hooking them up to an airport tug.
The resulting savings could be huge, which has enticed Delta Airlines to invest in the new technology, initially for its Boeing 737s. “Even a moderately sized fleet could save tens of millions of dollars per year,” says Walt Klein, Delta’s director of engineering, quality and training. WheelTug’s projections put the savings at $60,000 per month on a typical 737 involved in regional runs, according to Isaiah Cox, CEO of WheelTug, which is a subsidiary of Chorus Motors.
All those savings come from a variety of sources. One big one is the direct savings of burning less fuel when the turbines no longer have to push the aircraft to the runway. And there’s an indirect fuel savings, too. To account for taxi time, airlines often have to load more fuel onto the plane then they need for the flight itself. The weight of that extra fuel, if it’s not all burned on the ground, potentially poses a secondary drag on fuel economy.

see the link above for more detail and imagery/graphics/graphs

OVERTALK

WHBM

Good morning Rahosi

http://www.flyertalk.com/forum/showthread.php?t=718298

Hand Solo

Does wheeltugs designer have any figures for the fuel penalty involved in lugging around all that extra weight for the many hours the aircraft is in the air as opposed to the time it spends taxying?

Capt Pit Bull

say what?

pb

llondel

Hand Solo:
Who says it's a penalty? If you've got to load fuel for the engines to do the same job, it's quite possible that the efficiency of the wheeltug is such that it's still more economical to lug it around than it is to have to burn fuel in the engines to move the aircraft on the ground. However, it would be interesting to see figures for a full flight profile gate to gate with typical taxi delays.

Dave Gittins

Sounds fine on first look but ....

As pilots are notoriously unable to see behind them, this will still need somebody on the ground to either direct or control the equipment and steering at pushback. How complex could that be ? Or are we going to put video cameras in tail and wingtips ??

There is a weight penalty for every aeroplane which needs to be offset against fuel. Will one pushback be more expensive than lugging the equipment (say 500 kg inc batteries as I somehow doubt an APU providing enough amps to drag the aeroplane about) on a 12 hour plus sector ?

This will need to be fited on every aeroplane to be effective but a tug can push ... what ? a plane every half hour ??

Just musings ......

Rainboe

Very unconvinced. The engines provide motive energy whilst the APU is shut down. They also provide electrical power and airconditioning through compressors. So this system uses APU alone to provide all that electrical energy (considerable!), enough to get a heavy aeroplane up slopes, as well as providing compressed air for cabin conditioning. Going to take a far beefier APU with an enormous alternator to provide that energy...which will burn far more fuel than APUs currently do. Then, we're going to put those electrical motors in the same space that brakes currently occupy in wheel hubs, where they will not only get roasted to oven temperatures from -60 degrees C, but regularly doused with large quantities of water and dirt. And the downside, apart from first cost and complexity of maintenance, is significant extra weight of these large motors being carried throughout flight.

I'll believe it when I see it working reliably. Which it won't.

rahosi

Good afternoon
(Sorry for the delay, been down Costco doing the shopping.)

Wonderful thing Google alerts...

Rainboe

The discussion point is not Google alerts it's electrical push devices. Concentrate will you!

WHBM

Rainboe, old chap, it's an in joke. Do please keep up ......

Rainboe

Pray let me in on it please? Maybe don't bother.......

Intruder

AFAIK, the proposals are for nosewheel installation, where there are no brakes.

OTOH, your concerns about electrical loads are valid...

BRAKES HOT

ermm, am i missing something? How could batteries be more powerful than an APU gen?

ChristiaanJ

What's this APU thing?
I thought you normally started both engines before pushback, to power systems, aircon, etc. And did a proper checklist.

If we're now talking again about starting the engines just before line-up and take-off.... we're back to an earlier thread about taxying with tugs (does "RB" remind you of something?).
With all the consequences, like huge bottlenecks on the entry point to the runway, when sumptin goes belly-up?

And, as said here, has anybody done a proper balance sheet?

west lakes

Interesting electrically, weight is quoted as 200lb.

In theory as it is thyristor driven it could also be used as a regenerative braking system (as long as the power produced can be absobed by the a/c systems)

Rainboe

This now becomes a joke! Like those 2 dinky nosewheel tyres (on anything, even a 747) are going to have enough traction? Even pushback tugs with oversize tyres and weighing anything up to 20 tons or more can be slipping and sliding. And when wet- no traction at all! You would still need investment in all the pushback tugs (and their groundstaff) for windy or wet days.

It's a joke. It won't work. It's those bloody greens again. Don't listen to them.

rahosi

For those that don't know me, I am associated with the company, Borealis it's parent, and all the other subsidiaries. Not an employee, but under NDA (Non Disclosure Agreement). I am a BOREF shareholder as in most of the subs too. Rainboe, you are not the only one that thinks I am a dork (and worse). Be assured I will never lie.

I usually post on Raging Bull (BOREF). However do not expect me to break the NDA because I WON'T.

For those that doubt the whole thing, look at the video of the PROOF OF CONCEPT tests WT ran with Air Canada & Boeing back in 2005 (Actually before my time under NDA). That clunky (v0.1, my terminology) rig was NEVER intended to fly only to prove the concept, which it did.

Here, most of the questions and points of view could be answered by doing some simple research on the WT web site. Since I am not paid to field questions here, please don't expect me to be a search tool for you. At times it is hard for me to remember what isn't public; often that is what takes me time.

For those that doubt the whole idea, it is not easy to get the likes of Boeing, Delta & Air Canada to agree to their names being publicly associated with another company. Newport Aeronautical is other. Other 'names' will be made public soon.

Financing the project is taking time. Meanwhile progress is being made towards the ultimate certification hurdle. There are numerous patents covering the IP.

In my 1st post I should have titled it Good Afternoon WHBM, who evidently posts under another ID on Raging Bull, but I know not which. Evidently he guessed right (or maybe lured me...) that I would show up here. I was previously aware of this forum (and a few others) where WT is discussed. However I hadn't previously posted. (Please excuse my 1st brief post; my family was just arriving for dinner.)

(I'm away for a couple of days.)

CAT II

Just so you know, all 18 wheels on the 747 (all series) are the same size and interchangeable.

Rainboe

I believe the traction problem is insurmountable. Aprons have fuel spillages, de-icing residues, oil spillages. Put a little covering of water on that, and traction using just 2 nosewheel tyres (no tread) is not possible, especially when there is an upslope, as taxiways often have. Parking positions are usually depressed making initial movement difficult. Even with a heavyish 737, in the rain, a large pushback tug with a big engine can have trouble to the extent that the groundcrew occasionally ask for the start to be delayed to avoid having to push against the aircraft engines. If a large aircraft tug with a big diesel e.ngine can struggle sometimes, how can a small electric motor cope? I would have thought it would require a larger APU to be certified.

Good luck if you can pull it off, but I cannot see it working.