A320 Electric Jet
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Joined: Aug 2003
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From: Sale, Australia
A320 Electric Jet
EADS APU-Powered Electric Wheels for A320 Family
Airbus engineers have patented a still-experimental taxiing system for the A320 family, which includes the Airbus Corporate Jet, that uses electrically driven wheels to reduce fuel consumption during ground operations at airports and allow autonomous push backs.
EADS says the system uses electric "actuators" powered by the aircraft's auxiliary power unit (APU) to drive the landing gear wheels. Fuel consumption is expected to be five times less using the APU as compared to using engine power -- saving as much as 200 kg of fuel per flight compared with current airport processes. In addition, this alternative eliminates the need for a tug to push airlines away from the boarding gate.
The demonstration phase of the project is scheduled to close in 2012 with full-scale taxi tests beginning in 2013. If all goes as planned, EADS says initial flight tests will take place the following year.
From Aviation Weeks BCA Bulletin.
Airbus engineers have patented a still-experimental taxiing system for the A320 family, which includes the Airbus Corporate Jet, that uses electrically driven wheels to reduce fuel consumption during ground operations at airports and allow autonomous push backs.
EADS says the system uses electric "actuators" powered by the aircraft's auxiliary power unit (APU) to drive the landing gear wheels. Fuel consumption is expected to be five times less using the APU as compared to using engine power -- saving as much as 200 kg of fuel per flight compared with current airport processes. In addition, this alternative eliminates the need for a tug to push airlines away from the boarding gate.
The demonstration phase of the project is scheduled to close in 2012 with full-scale taxi tests beginning in 2013. If all goes as planned, EADS says initial flight tests will take place the following year.
From Aviation Weeks BCA Bulletin.
Joined: Dec 2010
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From: New York & California
This basic concept is actually very old: Anyone here ever read about Gustave Weisskopf? Either way, the man created an early aircraft, called the Whitehead 21", which was based around a boat-hull fuselage with a pair of wheels, a rudder in the back, wings based on Otto Lilienthal's designs, two tractor propellers driven by a type of steam-engine of his design (which was later used to power trains in Australia if I recall).
Now you might ask: What does this have to do with an A-320 using electrically driven wheels to help it taxi? Well, the Whitehead 21 actually used the engines to spin the wheels for accelerating along the ground initially; as the plane's speed would build, power would be transferred to the propellers prior to takeoff.
Now you might ask: What does this have to do with an A-320 using electrically driven wheels to help it taxi? Well, the Whitehead 21 actually used the engines to spin the wheels for accelerating along the ground initially; as the plane's speed would build, power would be transferred to the propellers prior to takeoff.
Joined: Dec 2002
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From: Where the Quaboag River flows, USA
It would be interesting to know the weight penalty--electric motors are not light and there is no use for them once airborne, significant fuel cost carting them around. I am open to the idea.
Can't wait for the Pprune thread, "Crew attempts take-off but forgot to start engines"
GF
Can't wait for the Pprune thread, "Crew attempts take-off but forgot to start engines"
GF
Joined: Dec 2010
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From: New York & California
galaxy flyer
So fuel efficiency would have to outweigh the weight penalty for it to work?
I can easily imagine this happening. Let's just hope those electric motors can't move the airplane much above 25 knots (I know Ryanair and Southwest would howl at that prospect 
but as I understand, you shouldn't really be taxiing above 25 kts anyway).
It would be interesting to know the weight penalty--electric motors are not light and there is no use for them once airborne, significant fuel cost carting them around. I am open to the idea.
Can't wait for the Pprune thread, "Crew attempts take-off but forgot to start engines"
but as I understand, you shouldn't really be taxiing above 25 kts anyway).
Joined: Apr 2008
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From: A tropical island.
That problem (or potential for it) could easily be remedied by having an auxillary throttle for the motors instead of routing it to the engine throttles (probably what they're doing anyway).
We already have too many "stupid pilot checklists" being forced upon crews don't need another 5 because somebody forgot that you need the engines on to take off.
Why the 
not... I'm taxiing to get out of an airport, not take a scenic drive.
We already have too many "stupid pilot checklists" being forced upon crews don't need another 5 because somebody forgot that you need the engines on to take off.
...but as I understand, you shouldn't really be taxiing above 25 kts anyway.
not... I'm taxiing to get out of an airport, not take a scenic drive.
Last edited by aviatorhi; 20th January 2011 at 07:02.
Joined: Jun 2001
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From: OZ
aviatorhi,
Think about tyre sidewall flexing and tyre carcase temperatures for a moment, then contemplate the damage a long, fast taxi can do to your tyres. What is the recommended distance limit again? Just check with the tyre manufacturers. Remember the problems when the reef runway opened in HNL.
Perhaps a 25Kt limit would be a very good thing.
Think about tyre sidewall flexing and tyre carcase temperatures for a moment, then contemplate the damage a long, fast taxi can do to your tyres. What is the recommended distance limit again? Just check with the tyre manufacturers. Remember the problems when the reef runway opened in HNL.
Perhaps a 25Kt limit would be a very good thing.
Only half a speed-brake
Joined: Apr 2003
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From: Commuting not home
Taxi consupmtion CFM 12 kg/min. APU 2 kg/min. Minimum warm up 3 mins. to save 200 kg you need 200/(12-2)+3 = 23 minutes taxi time. To break even need to consider increased fuel burn on each and every sector due weight and maintenance cost.
It may be viable, but "up to 200 kgs" is marketing communication. True, tug cost and flexibility will play a substantial role. For CJ even maybe tug non-availability.
FD (the un-real)
It may be viable, but "up to 200 kgs" is marketing communication. True, tug cost and flexibility will play a substantial role. For CJ even maybe tug non-availability.
FD (the un-real)
