There was a time when electric nose wheels were all the rage.

1) Plane can push back itself (save $$$$)
2) Plane can taxi on just the APU, shut down the main engines and save $$$$.

The concerns were cost and more importantly weight.

What's the current state of this? Anyone buying them yet? Any new technical progress

All the rage? When was this time?

I seem to have missed that rage.

Electric motors will weigh too much to make up the difference.in fuel burned
APUs do not even come close to offering enough thrust to move an aircraft

EMBQA wrote:

APUs do not even come close to offering enough thrust to move an aircraft

Obviously you won't use the APU's thrust, but rather the electric power generated by it to drive electric motors on the landing gear wheels. Systems like that are being studied and developed.


Gruß, masi1157

a common issue withanything new is the concept of diminishing returns. Electric nosewheels sound awesome on a forum. Yes, APU's burn less fuel than the engines taxiing. However, the extra wieght that the aircraft has to drag around while in flight offset those advantages. Since aircraft make money while flying, making them the most effecient as possible means making them light as possible, which also means not putting overly heavy components onboard that are only used on the ground.
Then you have to look at the complexity factor. Now there are electric nosewheel motors that need to be inspected at regular intervals. Then they also need to be replaced at regular intervals, it also adds another system to the aircraft that could cause delays or more maintenance. All of this adds up to cost, multiplied across several aircraft in a fleet. Whereas a few tractors can move several aircraft around much cheaper, or taxiing with only a few engines running save on fuel costs, much more so then electric motors attached to the nosewheels which add to the weight of the aircraft when it's flying.

I remember reading about them a decade ago; however I don't believe there was much interest or rage to speak of. Honeywell did install one on an A-320 for testing, but couldn't interest anybody. Most from this blurb:
https://en.wikipedia.org/wiki/EGTS

RetiredWeasel wrote:

I remember reading about them a decade ago; however I don't believe there was much interest or rage to speak of. Honeywell did install one on an A-320 for testing, but couldn't interest anybody. Most from this blurb:
https://en.wikipedia.org/wiki/EGTS

WheelTug (the make of one version) says "WheelTug expects entry-into-service in approximately two years, starting with these airlines. "
KLM
El Al
Icelandic
and 11 more

Has anyone heard more about this, or it is just vender hype.

http://www.wheeltug.com/

Where were all these aircraft that were "all the rage?" When did this rage occur?

These statements, made as if true, are not. Why make them, then?

RetiredWeasel wrote:

I remember reading about them a decade ago; however I don't believe there was much interest or rage to speak of.

As I said earlier, such a system is currently being studied and developed. It wil drive a wheel of the main landing gear, not the nose gear. An earlier version had been tested, but it moved the aircraft much too slow.


Gruß, masi1157

I think that it's a lot like other industries where people try to apply techologies that are suposes to make for a greener planet and in their zeal to bring their ideas forward, they ignore the downsides of their brand spanking new save the planet idea.

A good example of this mindset is the ideas of makeing all forms of transportation electric. With this idea, they fail to think through the fact that with everyone on the grid, we would have to build substantually more powerplants and have a network of dedicated charging stations. Right now, in the U.S., 63% of the powerplants are powered by fossal fuels so all the electric car cult would be doing is moving fossal fuel use off of the road and to where electricity is generated by massive powerplants and distributed by a massive grid to charge heavy batteries all at a loss of efficency.

The electric motor taxiing airplane is a solution looking for a problem. Just how fast coud electric and/or bleed air from an APU taxi an aircraft anyway? With most legacy aircraft that have only 90KVA available from the APU how fast could an aircraft taxi and still be able to suply required hydralic and electrical systems loads?

EMBQA wrote:

Electric motors will weigh too much to make up the difference.in fuel burned
APUs do not even come close to offering enough thrust to move an aircraft

If you need a 300HP tug to move an airplane? Then where would you put the 300 HP motor on the NLG??

stratclub wrote:

I think that it's a lot like other industries where people try to apply techologies that are suposes to make for a greener planet and in their zeal to bring their ideas forward, they ignore the downsides of their brand spanking new save the planet idea.

A good example of this mindset is the ideas of makeing all forms of transportation electric. With this idea, they fail to think through the fact that with everyone on the grid, we would have to build substantually more powerplants and have a network of dedicated charging stations. Right now, in the U.S., 63% of the powerplants are powered by fossal fuels so all the electric car cult would be doing is moving fossal fuel use off of the road and to where electricity is generated by massive powerplants and distributed by a massive grid to charge heavy batteries all at a loss of efficency.

The electric motor taxiing airplane is a solution looking for a problem. Just how fast coud electric and/or bleed air from an APU taxi an aircraft anyway? With most legacy aircraft that have only 90KVA available from the APU how fast could an aircraft taxi and still be able to suply required hydralic and electrical systems loads?

Only 90 KVA?? That kind of power can run a small office building elevators and all! The Problem isn't the power. It's where do you put the Electric motors? It takes
30 minutes to replace the pair of Nose wheels. how much time would you give it to replace a Nose wheel electric motor and at what cost?? And keep in mind that a 777 weighs in around 700K lbs at pushback for an international departure. And the Tugs that push them back weigh 90-110Klbs.

747Whale wrote:

Where were all these aircraft that were "all the rage?" When did this rage occur?

These statements, made as if true, are not. Why make them, then?

I'm sorry if I was unclear.

There was a time when there was much talk of adding such systems. Research was being done, and money spent. Things went from "I've never heard of this" to "wow, a lot of people are talking about this". I was curious how things stood now.

stratclub wrote:

I think that it's a lot like other industries where people try to apply techologies that are suposes to make for a greener planet and in their zeal to bring their ideas forward, they ignore the downsides of their brand spanking new save the planet idea.

A good example of this mindset is the ideas of makeing all forms of transportation electric. With this idea, they fail to think through the fact that with everyone on the grid, we would have to build substantually more powerplants and have a network of dedicated charging stations. Right now, in the U.S., 63% of the powerplants are powered by fossal fuels so all the electric car cult would be doing is moving fossal fuel use off of the road and to where electricity is generated by massive powerplants and distributed by a massive grid to charge heavy batteries all at a loss of efficency.

The electric motor taxiing airplane is a solution looking for a problem. Just how fast coud electric and/or bleed air from an APU taxi an aircraft anyway? With most legacy aircraft that have only 90KVA available from the APU how fast could an aircraft taxi and still be able to suply required hydralic and electrical systems loads?

I do know that Wheel Tug has a working system, and it works. So there must be enough space and power to make it work. One can retrofit it onto existing aircraft. Including a 737.

It goes in the nose wheel. Installed over night. Comes with a camera to help you back away from the gate.

You can watch the video at https://youtu.be/y7scGh7u10Y
Or see the web site at http://www.wheeltug.com/

Facinating. Do they have a working prototype yet? The 2017 Paris Airshow film did not show a working model of the system. It looked like in the non CG footage with a real aircraft, the aircraft may have been on downhill ramp and most of the acceleration was because of that. When the aircraft turned back towards the hanger after stopping the aircraft went about 1/2 MPH and they quickly moved away from that scene. Not showing any details of the instalation other than the hubcaps to me looks suspect.

Do you have any specs on the system such as horsepower, RPM, and especially taxi speed, electrical load and additional weight per wheel? They nariators asertion than an aircraft pushback is some kind of complicated mysterious and exspensive activity performed by neandrathals is really a stretch.

Delete Please

kitplane01 wrote:

I do know that Wheel Tug has a working system, and it works. So there must be enough space and power to make it work. One can retrofit it onto existing aircraft. Including a 737.

It goes in the nose wheel. Installed over night. Comes with a camera to help you back away from the gate.

You can watch the video at https://youtu.be/y7scGh7u10Y
Or see the web site at http://www.wheeltug.com/

Interesting that in these promotional videos, 95% of the footage of the Wheel Tug is basically used on toy models of the 737. Would love to see all of those features demonstrated on an actual aircraft.

How is it safer for a pilot to back the aircraft using a "wheel tug" without any ability to see where he's going?

A tug operator can see under the aircraft, and around it, and can much more effectively maneuver the aircraft out of parking and into place. Further, stopping rearward movement with a tug is simple. Stopping it by applying aircraft brakes is a good way, in many cases, to drop the airplane on its tail.

Engine starts are possible during pushback in many cases, enabling taxiing to begin shortly after completing pushback. It's not going to be possible to push back with the wheel tug and start engines, adding time, rather than reducing time as the videos suggest.

The youtube video suggests that with the wheel tug, aircraft can utilize two gates. We could devote quite some space to discussing why that's not going to happen, starting with high gate demand, and followed up with maneuvering space in and out of the gate area.

Taxi to the runway with "wheel tug" and then start engines? There might be some occasions when that's a good idea, but by the time we reach the runway, we need to be ready to fly, not to being with the before start engines checklist, start engines, do an after start, taxi, and before takeoff. Arrival at the runway is assumed to mean the crew is ready unless they advise otherwise.

What provision is given to the potential engagement of the drive in the nosewheel during takeoff or landing, or failure to disengage?

rjsampson wrote:

kitplane01 wrote:

I do know that Wheel Tug has a working system, and it works. So there must be enough space and power to make it work. One can retrofit it onto existing aircraft. Including a 737.

It goes in the nose wheel. Installed over night. Comes with a camera to help you back away from the gate.

You can watch the video at https://youtu.be/y7scGh7u10Y
Or see the web site at http://www.wheeltug.com/

Interesting that in these promotional videos, 95% of the footage of the Wheel Tug is basically used on toy models of the 737. Would love to see all of those features demonstrated on an actual aircraft.

Go watch the video. There is a real 737 at 38 seconds and at 54 seconds,.

stratclub wrote:

Facinating. Do they have a working prototype yet? The 2017 Paris Airshow film did not show a working model of the system. It looked like in the non CG footage with a real aircraft, the aircraft may have been on downhill ramp and most of the acceleration was because of that. When the aircraft turned back towards the hanger after stopping the aircraft went about 1/2 MPH and they quickly moved away from that scene.

The video and the web site both show working prototypes.

From a press release "Gibraltar, 14 January 2019 - WheelTug plc, the aviation electric taxi innovator, and Ethiopian Airlines, the largest carrier in Africa, have agreed to allocate 30 WheelTug systems to Ethiopian's Boeing 737 fleet. This agreement raises the number of assigned WheelTug slots to almost 1,300 aircraft across more than two dozen airlines worldwide. Ethiopian follows eight airline signings for WheelTug in 2018. "

I don't know, but I assume they have everything working.

stratclub wrote:

Not showing any details of the instalation other than the hubcaps to me looks suspect.

I disagree. It's a marketing video. They want everything to look easy and simple. I assume the sales people have someone who can also talk engineering, but that's not on their marketing video.

Airlines are in a fiercely competitive market, if savings are to be found, they will be found. That ideas like this and the brakes are instituted gives lie to them being cost savers. Airlines will do anything to reduce costs.

GF

Allegedly, wheeltug's plan for certification of their device was signed off by FAA in January 2017 for certification in late 2018 on 737NG.
I couldn't find a single mention of wheeltug on FAA web site, though, and apparently no certification.
System shown in the video is obviously non-certifiable with cable basically free hanging and inviting FOD issues.
Which gives...

GalaxyFlyer wrote:

Airlines are in a fiercely competitive market, if savings are to be found, they will be found. That ideas like this and the brakes are instituted gives lie to them being cost savers. Airlines will do anything to reduce costs.

GF

I agree, it is fiercely competitive, and I agree that if saving can be found they will.

Winglets were invented, and then some new company promoted them, and now they are everywhere. There was a change from no-winglets-anywhere to lots-of-winglets. Wheel tug could be the company that does this for electric taxi, just like BLR did for winglets (or whoever it was). It is not the case that since we don't see them now, they must not be a good idea. That would have also argued against winglets during the 1980s.

I'm not sure it's actually gonna happen. There are 100 bad ideas for every good idea. Thus my original post .. does anyone know the status. My conclusion from reading what everyone posted is that no one has heard of them being introduced, which is not a good sign for the idea. Also, I wonder if the web site is more flash than substance.

kitplane01 wrote:

It is not the case that since we don't see them now, they must not be a good idea. That would have also argued against winglets during the 1980s.

Your logic is flawed. Winglets, and other wingtip enhancements, have a proven benefit against their costs.

kitplane01 wrote:

My conclusion from reading what everyone posted is that no one has heard of them being introduced, which is not a good sign for the idea.

Correct, because, in the fiercely competitive markets of aircraft manufacture and airline operations, the cost/benefit analysis has appeared to condemn the idea of electric nose wheels to the trash heap of potentially money saving ideas...at least in its current form.

Winglets save money, heavy electric motors save a small amount of time and fuel, but add weight and fuel burn


Gf

GalaxyFlyer wrote:

Winglets save money, heavy electric motors save a small amount of time and fuel, but add weight and fuel burn


Gf

People keep talking about heavy motors... Nope, motors are not heavy.
Consider this one: https://www.dhxmachines.com/hawk60.html
35 kW long run, 55 kW peak, 13 kg/30 lb. A pair of such motors would pretty much max out 90 kVA of 737 APU, for a weight of 1/4 of a single non-rev or 1/5 of winglets weight.
Gearbox and wiring would make things worse, of course. Still if we need talk extra fuel- probably few $ for most legs - vs the cost of pushback tug.
I strongly doubt that this would work for long-range taxi, as such motor pair is still on par with Honda Civic engine (not too impressive compared to those tugs). Which actually brings the question if APU generator is strong enough for the task to begin with.
It may get more involved with economics beyond first glance: maintenance, contingency planning, logistics - but after all put the blame where it belongs.

The 787 might be viable. 2 450 KVA generators on the APU could probable produce enough power to do it and still run some ECS, lighting and some system required for taxiing. Having electric brakes, the 787 would only need 1 hydraulic pump for Nose Gear Steering. NGS could be inhibited during taxi without causing a safety issue Because the tanks would still be O2 low/nitrogen enriched from the NGS system running while the airplane was at the gate.

Mounting the motors on the mains would be better for W&B and allow for more room for routing the massive power feeders to a controller in a power panel in the Aft electronic equipment center aft of the main W/W's.

Total weight for the system? IDK.

EDIT TO ABOVE POST.
"Mounting the motors on the mains would be better for W&B and allow for a short wire run more room on the main gear than on the nose gear for routing the power feeders to high amperage controllers in left and right power panels in the Aft electronic equipment center aft of the main W/W's".

747Whale wrote:

How is it safer for a pilot to back the aircraft using a "wheel tug" without any ability to see where he's going?

A tug operator can see under the aircraft, and around it, and can much more effectively maneuver the aircraft out of parking and into place. Further, stopping rearward movement with a tug is simple. Stopping it by applying aircraft brakes is a good way, in many cases, to drop the airplane on its tail.

Engine starts are possible during pushback in many cases, enabling taxiing to begin shortly after completing pushback. It's not going to be possible to push back with the wheel tug and start engines, adding time, rather than reducing time as the videos suggest.

The youtube video suggests that with the wheel tug, aircraft can utilize two gates. We could devote quite some space to discussing why that's not going to happen, starting with high gate demand, and followed up with maneuvering space in and out of the gate area.

Taxi to the runway with "wheel tug" and then start engines? There might be some occasions when that's a good idea, but by the time we reach the runway, we need to be ready to fly, not to being with the before start engines checklist, start engines, do an after start, taxi, and before takeoff. Arrival at the runway is assumed to mean the crew is ready unless they advise otherwise.

What provision is given to the potential engagement of the drive in the nosewheel during takeoff or landing, or failure to disengage?

American used to do Powerback's from the gate. Until they put a wing into another Airliner which grounded Both of them. Good experiment while it lasted, highly unsafe on a crowded terminal ramp.

kalvado wrote:

35 kW long run, 55 kW peak, 13 kg/30 lb. A pair of such motors would pretty much max out 90 kVA of 737 APU, for a weight of 1/4 of a single non-rev or 1/5 of winglets weight. Gearbox and wiring would make things worse, of course. Still if we need talk extra fuel- probably few $ for most legs - vs the cost of pushback tug.

55 lb ft of torque each. So you are going to need torque multiplication as in a gear box. (much more weight)
Then of course you left out that these were liquid cooled. So plumbing, pumps, tanks, coolant and electrics. (much more weight)
Then the weight of the cabling, electrics, VFD's for the motors (much more weight)

You need to present us with some more realistic numbers. This is sounding like you can keep your doctor.

Okie

Okie wrote:

kalvado wrote:

35 kW long run, 55 kW peak, 13 kg/30 lb. A pair of such motors would pretty much max out 90 kVA of 737 APU, for a weight of 1/4 of a single non-rev or 1/5 of winglets weight. Gearbox and wiring would make things worse, of course. Still if we need talk extra fuel- probably few $ for most legs - vs the cost of pushback tug.

55 lb ft of torque each. So you are going to need torque multiplication as in a gear box. (much more weight)
Then of course you left out that these were liquid cooled. So plumbing, pumps, tanks, coolant and electrics. (much more weight)
Then the weight of the cabling, electrics, VFD's for the motors (much more weight)

You need to present us with some more realistic numbers. This is sounding like you can keep your doctor.

Okie

kalvado wrote:

Gearbox and wiring would make things worse, of course.

You may ask your grandkids to get you another pair of reading glasses.
And without your last phrase, I would just let it slip...

There are high power air cooled motors, there are damn effective electronics (e.g. Navy wanted to have all submarine power to get switched within a pack of cigarettes-sized enclosure).
I suspect things will work reasonably weight wise, it is overall economics - primarily economics of the ramp - that will not make it. Wheeltug estimates savings of $500-1000 per leg. I don't see that as a realistic number.

strfyr51 wrote:

747Whale wrote:

How is it safer for a pilot to back the aircraft using a "wheel tug" without any ability to see where he's going?

A tug operator can see under the aircraft, and around it, and can much more effectively maneuver the aircraft out of parking and into place. Further, stopping rearward movement with a tug is simple. Stopping it by applying aircraft brakes is a good way, in many cases, to drop the airplane on its tail.

Engine starts are possible during pushback in many cases, enabling taxiing to begin shortly after completing pushback. It's not going to be possible to push back with the wheel tug and start engines, adding time, rather than reducing time as the videos suggest.

The youtube video suggests that with the wheel tug, aircraft can utilize two gates. We could devote quite some space to discussing why that's not going to happen, starting with high gate demand, and followed up with maneuvering space in and out of the gate area.

Taxi to the runway with "wheel tug" and then start engines? There might be some occasions when that's a good idea, but by the time we reach the runway, we need to be ready to fly, not to being with the before start engines checklist, start engines, do an after start, taxi, and before takeoff. Arrival at the runway is assumed to mean the crew is ready unless they advise otherwise.

What provision is given to the potential engagement of the drive in the nosewheel during takeoff or landing, or failure to disengage?

American used to do Powerback's from the gate. Until they put a wing into another Airliner which grounded Both of them. Good experiment while it lasted, highly unsafe on a crowded terminal ramp.

Powerbacks were common in the 80s with -9s and 727–no experiment it was SOP.

GalaxyFlyer wrote:

strfyr51 wrote:

747Whale wrote:

How is it safer for a pilot to back the aircraft using a "wheel tug" without any ability to see where he's going?

A tug operator can see under the aircraft, and around it, and can much more effectively maneuver the aircraft out of parking and into place. Further, stopping rearward movement with a tug is simple. Stopping it by applying aircraft brakes is a good way, in many cases, to drop the airplane on its tail.

Engine starts are possible during pushback in many cases, enabling taxiing to begin shortly after completing pushback. It's not going to be possible to push back with the wheel tug and start engines, adding time, rather than reducing time as the videos suggest.

The youtube video suggests that with the wheel tug, aircraft can utilize two gates. We could devote quite some space to discussing why that's not going to happen, starting with high gate demand, and followed up with maneuvering space in and out of the gate area.

Taxi to the runway with "wheel tug" and then start engines? There might be some occasions when that's a good idea, but by the time we reach the runway, we need to be ready to fly, not to being with the before start engines checklist, start engines, do an after start, taxi, and before takeoff. Arrival at the runway is assumed to mean the crew is ready unless they advise otherwise.

What provision is given to the potential engagement of the drive in the nosewheel during takeoff or landing, or failure to disengage?

American used to do Powerback's from the gate. Until they put a wing into another Airliner which grounded Both of them. Good experiment while it lasted, highly unsafe on a crowded terminal ramp.

Powerbacks were common in the 80s with -9s and 727–no experiment it was SOP.

Did they use wingwalkers? Would be reasonable precaution...
One thing I specifically like about wheeltug movie is how they show pushbacks with nosegear mounted camera. Great way not to see a high widebody at the next gate.
But we had some heated discussion about pushback assistance devices in another thread...

Yes, wing walkers and a marshaler at the nose. At MCO, the marshaller didn’t stop the reverse signal until it was too late and a EAL 727 went off the ramp. Trick is you can’t use the brakes, only forward thrust to stop.

GF

Pushing back with an electric drive on the nosewheel and no engine thrust means that the thrust isn't there to stop rear motion and unlike a tug (or counter a tipping moment), which keeps the aircraft from tipping when braking in rear movement, there's nothing holding that nosewheel down when the pivot point is the main gear.

fr8mech wrote:

kitplane01 wrote:

It is not the case that since we don't see them now, they must not be a good idea. That would have also argued against winglets during the 1980s.

Your logic is flawed. Winglets, and other wingtip enhancements, have a proven benefit against their costs.

kitplane01 wrote:

My conclusion from reading what everyone posted is that no one has heard of them being introduced, which is not a good sign for the idea.

Correct, because, in the fiercely competitive markets of aircraft manufacture and airline operations, the cost/benefit analysis has appeared to condemn the idea of electric nose wheels to the trash heap of potentially money saving ideas...at least in its current form.

I don't understand. I wonder if we're failing to communicate.

I think your saying something like "if airlines don't use them, they are likely a bad idea". But winglets were back in the 80's not used by airlines, and by that logic people in the 80's could have concluded that winglets were a bad idea. We now know that often winglets are a great idea, because things have changed/advanced.

I will agree that "airlines don't do it" is evidence of "it's a bad idea". But everyone once in a while people come up with new ideas and the world is improved.

It could really be that Wheeltug is a bad idea. Would not surprise me. But "airliners don't do it" is not proof (though it is evidence).

Really I think it comes down to this. If Wheeltug is honest and true, then 17 airlines and over 1,000 737's are scheduled for wheeltug's and it's probably a good idea for some airlines at some times. But if that's marketing BS ..

stratclub wrote:

EDIT TO ABOVE POST.
"Mounting the motors on the mains would be better for W&B and allow for a short wire run more room on the main gear than on the nose gear for routing the power feeders to high amperage controllers in left and right power panels in the Aft electronic equipment center aft of the main W/W's".

There was a different company that put it on the mains. I imagine (without being certain) that WheelTug prefers the nose wheel because there are no brakes on the nose wheel. Probably makes for an easier installation.

kalvado wrote:

I strongly doubt that this would work for long-range taxi, as such motor pair is still on par with Honda Civic engine (not too impressive compared to those tugs). Which actually brings the question if APU generator is strong enough for the task to begin with.

Wheeltug says it works, and has tested it with a real 737. Maybe they are telling lies, but the claim is that it works for a taxi to the runway.

kitplane01 wrote:

fr8mech wrote:

kitplane01 wrote:

It is not the case that since we don't see them now, they must not be a good idea. That would have also argued against winglets during the 1980s.

Your logic is flawed. Winglets, and other wingtip enhancements, have a proven benefit against their costs.

kitplane01 wrote:

My conclusion from reading what everyone posted is that no one has heard of them being introduced, which is not a good sign for the idea.

Correct, because, in the fiercely competitive markets of aircraft manufacture and airline operations, the cost/benefit analysis has appeared to condemn the idea of electric nose wheels to the trash heap of potentially money saving ideas...at least in its current form.

I don't understand. I wonder if we're failing to communicate.

I think your saying something like "if airlines don't use them, they are likely a bad idea". But winglets were back in the 80's not used by airlines, and by that logic people in the 80's could have concluded that winglets were a bad idea. We now know that often winglets are a great idea, because things have changed/advanced.

I will agree that "airlines don't do it" is evidence of "it's a bad idea". But everyone once in a while people come up with new ideas and the world is improved.

It could really be that Wheeltug is a bad idea. Would not surprise me. But "airliners don't do it" is not proof (though it is evidence).

Really I think it comes down to this. If Wheeltug is honest and true, then 17 airlines and over 1,000 737's are scheduled for wheeltug's and it's probably a good idea for some airlines at some times. But if that's marketing BS ..

"If airlines don't use them, they are likely a bad idea" is valid, but it must be thought of in the context of the economic conditions of the time. When jet fuel was cheap, the additional cost of winglets was not worth it. Increasing fuel cost, and decreased cost of computational fluid dynamics and manufacturing made them worth the price.

There's nothing wrong with electric hub motors per se, but at the present time they are not economically advantageous. If the total cost of implementation and use decreases below a certain point, they will be a good idea.

kitplane01 wrote:

Wheeltug says it works, and has tested it with a real 737. Maybe they are telling lies, but the claim is that it works for a taxi to the runway.

It's always best, when seeking truthful, accurate information, to get it from the salesman. Right?

I would love to know how these are meant to work in the winter. When it is snowing and the ramp is icy we have trouble pushing back aircraft with a TBL.(Towbarless tractor) There is no weight on the nosewheels, and the TBL is very light, and it is common practice for someone to have to throw gravel under the wheels to get some traction.
Perhaps the dispatcher will have to plan to load the aircraft nose heavy to get some grip.

kitplane01 wrote:

kalvado wrote:

I strongly doubt that this would work for long-range taxi, as such motor pair is still on par with Honda Civic engine (not too impressive compared to those tugs). Which actually brings the question if APU generator is strong enough for the task to begin with.

Wheeltug says it works, and has tested it with a real 737. Maybe they are telling lies, but the claim is that it works for a taxi to the runway.

Wheeltug supplies remarkably little information on their design, and I find little independent confirmation of what they say. They have some video of a very crude prototype, nothing certifiable. So I am skeptical.

Tristarsteve wrote:

I would love to know how these are meant to work in the winter. When it is snowing and the ramp is icy we have trouble pushing back aircraft with a TBL.(Towbarless tractor) There is no weight on the nosewheels, and the TBL is very light, and it is common practice for someone to have to throw gravel under the wheels to get some traction.
Perhaps the dispatcher will have to plan to load the aircraft nose heavy to get some grip.

Maybe planning for very slow pushback, like 10-20 seconds to accelerate to the speed of human walking? And then using same system as a brake to avoid tipping over?
Overall it can explain why main gear drive, seemingly a much more reasonable solution, is a second choice: no main gear brakes can be used, and working against thrust, even idle thrust, may be difficult.
That is a good explanation, IMHO, of why things are much more involved than it looks at a first glance.

Tristarsteve wrote:

I would love to know how these are meant to work in the winter. When it is snowing and the ramp is icy we have trouble pushing back aircraft with a TBL.(Towbarless tractor) There is no weight on the nosewheels, and the TBL is very light, and it is common practice for someone to have to throw gravel under the wheels to get some traction.
Perhaps the dispatcher will have to plan to load the aircraft nose heavy to get some grip.

I'm going to guess that if it only works 98% of the time, that's good enough. Most airports don't get real snow, and many other airports get snow like 4 days a year.

Now in Manitoba, this might be a bad idea. But please, reconsider living in Manitoba

747Whale wrote:

kitplane01 wrote:

Wheeltug says it works, and has tested it with a real 737. Maybe they are telling lies, but the claim is that it works for a taxi to the runway.

It's always best, when seeking truthful, accurate information, to get it from the salesman. Right?

I started with "I have a question". When my only source of information was the company, I made sure to point that out (see "Wheeltug says ... maybe they are telling lies".)

Sarcasm is not always helpful.

Here some informations about the Electric Taxiing project developped by Safran (the objective is an EiS by 2022).

https://www.safran-landing-systems.com/ ... tion_1.pdf

Electrical motors are constantly improved and the mass/power ratio is more competitve each year. This whole electric taxiing thing is a part of the global electrification of aircraft and it's just a matter of years until full deployment.

LaunchDetected wrote:

Here some informations about the Electric Taxiing project developped by Safran (the objective is an EiS by 2022).

https://www.safran-landing-systems.com/ ... tion_1.pdf

Electrical motors are constantly improved and the mass/power ratio is more competitve each year. This whole electric taxiing thing is a part of the global electrification of aircraft and it's just a matter of years until full deployment.

Hopefully, at some point, common sense will prevail and the mad dash to electric will stop and we can return to sanity. Even electrifying tugs and other forms of GSE is pretty stupid If you have to store the remotely generated electricity in heavy batteries that cause you to use more energy just to tote them around..

One of President Trumps best decisions was to pull us out of the Paris Global Warming Agreement. Planet stewardship needs to be taken away from the corrupt politicians with $ agendas and given back to real scientists. Over the last 30 years, none of the computer model predictions about climate have become true, not one.

LaunchDetected wrote:

Here some informations about the Electric Taxiing project developped by Safran (the objective is an EiS by 2022).

That is the one I was talking about earlier. It drives a wheel of the main landing gear and it is being developed. I think this is a useful system for short-haul aircraft, that do several flights, and therefore several taxiings per day. For long-haul it would be just ballast.


Gruß, masi1157

stratclub wrote:

LaunchDetected wrote:

Here some informations about the Electric Taxiing project developped by Safran (the objective is an EiS by 2022).

https://www.safran-landing-systems.com/ ... tion_1.pdf

Electrical motors are constantly improved and the mass/power ratio is more competitve each year. This whole electric taxiing thing is a part of the global electrification of aircraft and it's just a matter of years until full deployment.

Hopefully, at some point, common sense will prevail and the mad dash to electric will stop and we can return to sanity. Even electrifying tugs and other forms of GSE is pretty stupid If you have to store the remotely generated electricity in heavy batteries that cause you to use more energy just to tote them around..

One of President Trumps best decisions was to pull us out of the Paris Global Warming Agreement. Planet stewardship needs to be taken away from the corrupt politicians with $ agendas and given back to real scientists. Over the last 30 years, none of the computer model predictions about climate have become true, not one.

Tugs need to be heavy since the planes they are pushing are heavy. Its one thing to start a plane moving, but to get it stopped in a quick and safe manner requires weight...and of course brakes. You might as well carry heavy batteries as opposed to literally ballast...make the weight useful.

I agree with you that the rush to electrification could be thought out with more planning rather than what is currently happening, but where it is not required to use a hydrocarbon based fuel source such as ULH aircraft, its going to die out. I personally hate electric vehicles for my own personal use. I very much prefer the power curve of an internal combustion, but you get used to it.

kitplane01 wrote:

There was a time when electric nose wheels were all the rage.

1) Plane can push back itself (save $$$$)
2) Plane can taxi on just the APU, shut down the main engines and save $$$$.

The concerns were cost and more importantly weight.

What's the current state of this? Anyone buying them yet? Any new technical progress

I'm not.
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