http://www.youtube.com/watch?v=u4nZDX0Nglo

 

That's awesome, why they didn't think this before ?

I came across that some time ago, but I still find the idea very cool. I guess that's a lot of engineering work gone into that piece of technology, after all they couldn't really modify the landing gear too much, yet they had to fit in an engine that is powerful enough to move an aircraft that has about 80tons.

I recall KLAX back in the 1990's on smog days required aircraft to shut down the engines after landing and a tug would tow it back to the gate. Had this happen before but not sure if they do this any more. I remember the captain complaining about it to the passengers.

 

So this would hopefully save on pollution in a big city like KLAX that has air pollution problems.

 

Not sure what the numbers are for savings but it still needs a power source, so I wonder if the APU is running to power the wheel motors or is it drawing from the batteries. Also the additional weight will increase fuel consumption a little bit.

 

The technology has always been there to do this but now electric motors and batteries have become lighter and more efficient so maybe it is worth it.

This one looks as if it runs off the APU.

Ultimately it's all about the energy storage, batteries have come a long way and look as if the technology is maturing.

 

It's such a a cool idea... and if you could spin the wheels up prior to landing (are you listening, Honeywell?) you'd double the life of the tyres.

And regenerative braking would get you back a big piece of the energy used in the taxi.

 

All about the batteries... there's a little hesitancy about these in aviation, just ask a 787 project engineer.

I have watched the video again and the APU appears to be running in the video...however the APU is started up after landing any ways, so to be honest the system seams to be a marginal difference in the polluted markets...short route airlines in heavy populated cities may purchase this

This is what Lufthansa is doing in Frankfurt. Same system as EGTS I guess.

 

 

"eTaxi: electrically powered landing gear for taxiing procedures

The eTaxi project is investigating the application and technical integration of an electric drive on the main undercarriage for short and medium-haul aircraft for all taxiing movements on the apron. The drive energy for the system, integrated into the main undercarriage, is exclusively electric, generated and supplied by the aircraft's own APU. The motor can be used both for pushback and for taxi-out and taxi-in to and from the runway. The on-board system is controlled from the cockpit and could be deployed at any airport, independent of available infrastructure. To ensure a wide field of application, the retrofitting of the drive system to the Airbus A320 range of aircraft is being evaluated. This would require modifications on the main undercarriage."

Source: http://www.lufthansa-technik.com/emobility

 

So yes, the APU is needed to power the electric motors located at the main-undercarriage. They also tested a hybrid-towing vehicle for heavy aircraft with a range of about 7 kilometers (4-5 miles).