I can imagine that airlines like RyanAir are behind this idea. Why do you think they carry built in airstairs when every airport they land at has airbridges or steps that can be rolled up to the aircraft? They do it because RyanAir believe that it is cheaper for them to carry the weight of the stairs then it is to have to pay the charges for airport services at aevery airport they use.

 

The same will apply to a self powered pushback device. Having it does not mean they have to use it, but does mean they do not have to pay the airport. I do not think it is intended to replace the ground person, only the ground tractor.

 

As for the device having to be big and heavy, or the APU needing upgrading to provide the required power, have a look at the powermovers used to position caravans and other wheeled loads. If I can move a few tons of caravan with nothing more then the powerpack from a cordless drill, moving a loaded 737 should not prove to be a significant problem.

The power needed to get a fully loaded 737 moving should not be under estimated. Once moving the force required reduces of course, but the power reduces less. Any incline in a taxiway will add to the problem of keeping it moving.

 

Power required is rolling resistance times velocity. Even at 100% efficiency this power has to be produced.

 

Also as the main engines won't be running the APU will be powering all electrical systems, hydraulics and air conditioning. So it will need a higher rating.

Also as the main engines won't be running the APU will be powering all electrical systems, hydraulics and air conditioning. So it will need a higher rating.

 

The NG's APU's (AS 131's) have lots of stink in em on the ground. 2 Packs and all the (usual) electrical power you need is no problem. Using a driven compressor rather than bleed air really give the things lots of capacity. Things start getting dicey when you start running fuel pumps and the elec hydraulic pumps.

 

Running both Hyd. pumps would put a strain on things I suppose.

 

But you are right. Lot's of checklists would have to be differed till the last minute.

 

If this stuff takes off, I think we'll see it first adopted by European operators. They are starting to institute some pretty strict restrictions regarding engine/apu use on the ground at these facilities, and the greatest benefit would be at a place like EHAM.

 

Meanwhile in gun-totin', oil burning yee-haw North America, we will stick with out cool sounding fuel-suckin' engines thank you very much .

Running both Hyd. pumps would put a strain on things I suppose.

 

But you are right. Lot's of checklists would have to be differed till the last minute.

 

If this stuff takes off, I think we'll see it first adopted by European operators. They are starting to institute some pretty strict restrictions regarding engine/apu use on the ground at these facilities, and the greatest benefit would be at a place like EHAM.

 

Meanwhile in gun-totin', oil burning yee-haw North America, we will stick with out cool sounding fuel-suckin' engines thank you very much .

That's the point, you won't be able to pushback and taxi in this way without hydraulic power. Fuel pumps can wait until main engine start, but APU load will still be high. That means more CO2 and more noise. What would you do at airports where APU use is restricted or prohibited? Exactly the kind of noise sensitve airports you mention. Main engines will still have to be started early enough to allow them to warm up and what if one airliner in a long queue then finds it has an engine problem and has to return to the terminal?

 

I see this as a convenience issue rather than a green issue. People forget that the energy to taxi has to be produced somehow. The only thing that matters is how efficient it is. Unless the power source is a renewable supply or nuclear then it will have a CO2 impact.

 

Even you gun-totin' gas guzzlin' Americans have bean counters who insist on things like single engine taxi. That's the only way this will be adopted, if it saves the airline money.

I wonder how much or if this thing will be a maintenance pain, also after landing does the aircraft need to come to a complete stop after the 3 minute engine cool down to engage the system? How would the APU handle this on a very hot day while providing bleed air for the AC packs, power to all the needed hydraulic pumps, and electrical power. Maybe the beefy 747 and 777 APU might not have an issue but what about the 737 or A320.

 

Will the system have a ground override so the crew chief can push the plane himself? Pilots can't see behind them and not all gates have a straightforward push back. How will the system handle snow, slush, and wet surfaces? As for limited APU use or ban, how do they manage that as many times the PCA hose can barely keep some aircraft cool so the APU is essentially required to keep the cabin at a reasonable temperature, this is a major issue with the MD-80 in particular.

Even you gun-totin' gas guzzlin' Americans have bean counters who insist on things like single engine taxi. That's the only way this will be adopted, if it saves the airline money.

 

Where I live we are even worse than the Americans. It's too bloody cold to not have both engines and the apu warming things up :LMAO: .

WheelTug is planned to enter service Q4 2013

Usually WheelTug weighs no more than the taxi-in fuel not needed to be loaded.

A 737NG or A320 APU has sufficient spare capacity to power the system.

Regular engines are seriously inefficient on the ground.

The savings have been carefully researched by the company & numerous 3rd parties.

It even improves the efficiency in flight (typically 0.5%): Over a period of time, engines suffer taxi FOD damage which is more prevalent on aprons (plus FOD damage from grit which blends the blades). Brake wear (especially on cold carbon brakes) is reduced. Many engines have 'power by the hour' contracts so running them less is another saving. Some airplanes that operate out of busy airports on short routes actually operate their engines longer on the ground than in the air!

Using WheelTug, the operating day can be lengthened at airports that operate a noise curfew. A WT plane can be in the air 5 minutes after engine warm-up commencement.

 

The average savings per flight will be more than the average profit per flight (Recent Wall Street Journal Report)!

 

of 2 weeks ago's tests in Prague. There are other WheelTug videos on YouTube. The full version will be ready for Farnborough.

Still, If I was an airline I wouldn't think of putting those things on my airplane until It could be operated from someone on the ground.

 

Backing out of a nice clear hangar area onto an empty taxiway is nice and makes good video (especially with the crane cam???), but at a busy airport?

 

Sorry, but pilots can't see (well at least on the 37) below and behind their wheels. Even having a guy talking him back on the intercom will probably have to either have a 15+ Ft cord or stand dangerously close to a powered wheel which he has little or no warning to what it's gonna do.

I dont know of any modern aircraft that the pilots can see whats behind them while there seated in the cockpit looking forward... I suppose they could ask the flight attendants to open the curtains so they can use the rear view mirror? haha

 

I'v been a rampie and im also a pilot. As a pilot i dont trust any ones judgement but my own... and as rampie, i didnt even trust my own judgement.. haha

 

I like the idea of having a tug or lektro.. means more job security..

 

Thanks

JR