Airbus Developing a way to taxi without engine power

[Chaxterium]

http://blog.flightstory.net/1603/airbus ... t-taxiing/

Currently Airbus is developing an alternative that, in near future, could replaces the use of jet engine thrust during ground taxiing with electrical power.

The solution is simple: an electric actuator, powered by the aircraft’s APU, drives the landing gear’s wheels. Fuel consumption is expected to be five times less than it would be with engine power – saving as much as 200 kilogrammes of fuel per flight. In addition, this alternative delivers a feature much requested by airlines, providing greater autonomy at push-back from the boarding gate as no tug is required.


Design and implementation for the project, a transversal process involving Airbus’ Engineering and Procurement department, is progressing in two concurrent stages. The demonstration phase is scheduled to close in 2012 with completion of the prototype electric wheel actuator. In parallel, the modified APU and power systems will be tested on the Airbus electrical test bench, with full-scale rolling tests to begin in 2013. If all goes as planned, initial flight tests will take place in 2014.

Source: Airbus
Image: Airbus

[Expat]

good idea! Some airports, loke CDG in Paris, require 20 minutes of taxi to get to the gate!

[sanjet]

Too me just looks like more weight and more things that can break down on an airplane.

[rigpiggy]

how much torque to breakaway, how much weight for the electric motor, extra wiring, controls etc....

Been looked at before not really feasible.

[whisair]

The installation might save it's own weight in fuel saved and if it breaks down you always have the engines.

[square]

Well itd be pretty neat sure, but how much is it worth developing if it only saves you two or three hundred bucks per flight?

[Flying Low]

Does this mean you have to put snow tires on for the winter season?

[modi13]

Well itd be pretty neat sure, but how much is it worth developing if it only saves you two or three hundred bucks per flight?

An A380 burns ~4000 gallons per hour. At $1.80 per litre of jet fuel, with a 15 minute taxi, that works out to $6804. Assuming the same amount of taxiing during departure and arrival, that's $13608. That's a pilot's salary for the year.

[Heliian]

Make the passengers push.

[dashx]

I believe they are commonly called "tugs" and powered by diesel fuel and if you use fuel removed when doing C/D checks its free........

Then again electric powered landing wheels spinning prior to landing would save some rubber....

How does a brake become a motor? Juat ask a Prius....

[v6g]

"Would be economy class passengers please now stow your foot-pedals in the upright position for take-off".

[square]

Well itd be pretty neat sure, but how much is it worth developing if it only saves you two or three hundred bucks per flight?

An A380 burns ~4000 gallons per hour. At $1.80 per litre of jet fuel, with a 15 minute taxi, that works out to $6804. Assuming the same amount of taxiing during departure and arrival, that's $13608. That's a pilot's salary for the year.

Well according to Airbus,

Fuel consumption is expected to be five times less than it would be with engine power – saving as much as 200 kilogrammes of fuel per flight.

[Siddley Hawker]

Fuel consumption is expected to be five times less than it would be with engine power – saving as much as 200 kilogrammes of fuel per flight.

Did Airbus say how much extra fuel it'll cost to fly all them goodies around each flight?

[Never Mind]

Bicycle pedals in the cockpit linked to the wheels. Pilots will never get fat.

Never Mind

[ogc]

Considering that most tugs have about 100hp/250ft lbs of torque.

You wouldn't need very large electric motors to do this, also the fact that there are no brakes taking up room in the front wheels, its completely possible.

Some newer electric vehicles come with an electric motor at each wheel with 100-150 hp a piece. If you can pack all that into a 4000 lb car, im sure they can figure a way to get it to work in a plane.

[rigpiggy]

lets see, here is the tug
http://www.neacorp.com/aircrafttugs/aircrafttug4.html

here is the engine
8V-71T 362hp/2100rpm tq 950# @2496#weight, then look at the wheels and figure they may move 21 rpm during pushback, so actually like 9500#/tq at the wheels, good luck

[square]

lets see, here is the tug
http://www.neacorp.com/aircrafttugs/aircrafttug4.html

Says here.. "We manufacture Passenger stairs, Jacks, Maintenance Stands, Refuelling / Defiling Carts / Trucks and Hydraulic Power Units."

One please!

[winds_in_flight_wtf]

Why not just incorporate fold out pedals for passengers. That way they can all pedal the airplane onto the numbers and in the event they refuse, there is a tooney coin slot in which they can insert the necessary change and opt out?

[TTJJ]

A system has been in the works since about 2005 that does this. It is fitted completely within the nose gear assembly. No modifications to the gear bay are required. This is probably the best idea I have ever seen for the airlines and should be coming soon (2012) to a Boeing near you. It weighs 250 lbs.
I worked 13 years at an airline and probably spent 2.5 of those years just taxiing. The fuel used really adds up over time.

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,

http://www.designnews.com/article/talkb ... d.php#2062

An Air Canada 767 was used for the proof of concept test. The motor used a generator for the test as the company was not allowed to wire into the Air Canada aircraft.



Recent testing was done for traction in the winter.




A different article, (which I can't find) said the fuel savings would be the same as installing winglets.

At 250 lbs each, American Airline will use 2.8 Million Gallons of fuel per year to carry the thing around. However, American Airlines burns 128 Million Gallons of fuel per year...just on the ground. Imagine the savings to be had.

For each pound of extra weight removed from an aircraft, AA saves as much as 11,500 gallons of fuel annually for AA's fleet of more than 600 aircraft. If 100 pounds of unnecessary weight was taken off each aircraft, AA could save more than 1.1 million gallons of fuel over the course of a year.
Even though the majority of AA's fuel is consumed in flight (95%), the remaining amount consumed on the ground (5%) adds up to 128 million gallons.

http://www.aa.com/i18n/amrcorp/newsroom/fuel-smart.jsp

[Gannet167]

It's a great idea and can save a lot of gas, particularly where there is a long taxi or big delays. Waiting in line at a large airport, watching all those engines burn all that gas is painful. I've always wondered why tugs aren't used to bring the aircraft to the button of the runway.

200 kilos of fuel is about 240 liters? However, not only do you save those 240 liters, you also have to carry less fuel enroute because you weight less. I don't know if Airbus is considering taxi fuel only, or the savings in enroute fuel as well.

It might be difficult to get all the electric/pneumatic/hydraulic/etc checks done that require engines running. Also, any thoughts on starting a big turbine and 30 seconds later going to takeoff thrust, particularly if it's a cold day?

[justwork]

how much torque to breakaway, how much weight for the electric motor, extra wiring, controls etc....

Been looked at before not really feasible.

Seriously? This comment makes you sound 100 years old. If engineers can put a person into space using a Saturn V rocket, I'm pretty sure someone can develop this technology into something reliable and feasible. Long taxi waits with engines off would quickly amount up to huge cost savings.

[Expat]

There were cases last year of up to 8 hours waits on the ramp...

[iflyforpie]

how much torque to breakaway, how much weight for the electric motor, extra wiring, controls etc....

Been looked at before not really feasible.

Seriously? This comment makes you sound 100 years old. If engineers can put a person into space using a Saturn V rocket, I'm pretty sure someone can develop this technology into something reliable and feasible. Long taxi waits with engines off would quickly amount up to huge cost savings.

+1


If they could make electric motors move a mile-long train 70 years ago, or a 35,000 ton aircraft carrier 80 years ago, then with the rapid advances in electrical technology in recent years it should be child's play to make electric motors powerful enough and light enough to move an aircraft.

Electric motors can spin at turbine-like speeds and through reduction gears should have no problem developing the torque to move an airliner that weighs a fraction of what a train or ship weighs.

[rigpiggy]

mile long trains, and 35,000 ton ships do not care about an extra bit of weight. airplanes do. the video above shows the system, however just from looking at it chain drive etc, I can't see it being either terribly durable or cost effective. Plus you'll still need tugs for when it is dmi'd

[Gannet167]

The extra weight must obviously be off set by the fuel savings. I have to think that the teams of engineers at Airbus would have already had enough common sense to figure that adding weight to an airliner has to pay off with at least as much economic savings - or why would they even try to make it work? I'm sure a 400,000 lb airplane can handle another 200 lbs. If it saves a couple of hundred bucks on each leg, that can add up over the life span of an aircraft, fleet wide.

I watched a tv show called "A Day in the Life of American Airlines." The president ordered all magazines removed from the fleet, as this 100-ish lb savings added up to something like a million bucks over a year, across hundreds of aircraft and thousands of flights. If a magazine was going to be carried, it had to generate as much revenue in advertising as it cost in fuel to fly around the world. A very eye raising fact they showed - a nearly fully loaded 767 from New York to LA cost over $26,000 to operate. It made something like $800 in profit on that one flight. If reducing fuel burn in the taxi can save $400, the profit margin is increased by 50%. I know many flights are far more profitable, but I'm sure there are many that barely make a dollar.

There's no way that Airbus hasn't done the math. Airlines also fly around with precious little extra gas. If dispatch has given you the minimum, but you expect a 30 minute delay, but it turns into an hour and a half - who cares? The APU fuel burn is likely so small that it doesn't change the crew's plan for the flight. No need to return to the ramp put on extra gas.