Corvette-Size Electric Motor Seen Changing How Jets Taxi
As fuel prices continue to soar, airlines are studying new technology that may save more than $200,000 per jet every year. The breakthrough only sounds mundane: It’s all about how planes taxi.
Travelers are familiar with the sight of low-slung airport tugs pushing aircraft away from the gate so the main jet engines can crank up safely. Thrust from the kerosene-slurping turbofans then powers planes into position for takeoff.
Now, equipment makers such as Honeywell International Inc. (HON) are devising electric motors that weigh about as much as V-8s in Chevrolet Corvettes yet pack enough torque to move 180,000-pound (81,650-kilogram) jets, letting pilots taxi without relying on main engines or diesel tractors.
“You could have tug-less airports,” said Ian Davies, chief of engineering and maintenance for EasyJet Plc (EZJ), Britain’s largest discount airline. “It might fundamentally change how we operate in airports.”
Taxiing on electric power is an example of how technology, in this case motors so small they fit in the hub of a jet’s nose wheel, can revolutionize something as routine as an airliner’s journey between the terminal and the runway.
“It’s a simple concept, but it’s complex to integrate into an aircraft,” said Olivier Savin, chief of Safran SA (SAF)’s Green Taxiing System Joint Venture with Honeywell. “Integration is the key to success.”
The prospect of annual savings topping $200,000 a jet from lower fuel use and less ground time has stirred interest from planemaker Airbus SAS and airlines such as EasyJet and Alitalia SpA. The first new aircraft with electric-taxi technology may be in production in as few as three years, and older planes may get the gear as soon as 2013.
Airlines face the highest sustained prices ever for jet kerosene, the industry’s largest cost, based on data compiled by Bloomberg. United Continental Holdings Inc. (UAL), the world’s biggest carrier, says it burns $25,000 of fuel a minute. Jet fuel for immediate delivery in New York Harbor has averaged $3.12 a gallon in 2012, more than four times as much as a decade ago.
Taxiing on one engine has become a common fuel-saving practice for twin-engine jets in recent years, and planes already make electricity when they’re at the gate by running small turbine engines known as auxiliary power units.
What’s new today is the convergence of airlines’ hunger for more efficiency and recent advances in miniaturizing electric motors to propel a plane at the 20 miles (32 kilometers) per hour it may need for taxiing.
The Honeywell-Safran team estimates its unit would weigh a maximum of 880 pounds, while startup WheelTug Plc said its electric-taxi technology is only about 300 pounds. Another entry, a venture between L-3 Communications Holdings Inc. (LLL) and Crane Co. (CR), isn’t commenting on the heft of its system.
WheelTug’s motor fits in the hub of a jet’s front wheel and is just 5 inches wide, Chief Executive Officer Isaiah Cox said. That’s half as broad as two years ago, when the Gibraltar-based company still had to attach the motors outside the hub, he said.
“It’s like packaging an elephant into the nose wheel of an airplane,” Cox said.
That would eliminate the cost of a push-back from a tug, which runs $50 to $150, and the consumption of about 55 gallons of fuel taxiing before and after takeoff, based on average burn rates and ground times at U.S. airports, Cox said.
WheelTug says its system may save about $500,000 a plane annually, including benefits such as less wear on engines.
Honeywell and Paris-based Safran say the savings may exceed $200,000 per plane a year by paring fuel use and ground time, and eliminating charges for tugs’ services. Stamford, Connecticut-based Crane also says taxiing on electricity would cut noise, reduce emissions and shrink the risk of having a jet’s main engines ingest tarmac debris.
Meshing small electric motors and new cockpit controls won’t be the only challenge for Morris Township, New Jersey-based Honeywell and its rivals.
Suppliers will have to convince airlines that the savings will make up for the extra fuel burned in flight from the equipment’s added weight, said Tim Campbell, president of St. Paul, Minnesota-based Mountain Vista Consulting and the former chief of regional operations for Northwest Airlines Corp.
Airport tugs also would need to be on hand in case a plane’s APU fails, Campbell said in a telephone interview.
Boeing Co. (BA) isn’t “actively pursuing” electric taxi, Terrance Scott, a spokesman, said in an e-mailed response to questions.
Airbus is talking with “potential suppliers” for an electric taxi system, Martin Fendt, a spokesman, said in a telephone interview, without identifying them. “It’s certainly something we’re keen to see where the potential is.”
WheelTug’s focus is to fit its electric-taxi system to existing jets, and it has installation agreements with Alitalia and El Al Israel Airlines Ltd. (ELAL) The company has a target of late 2013 to get the first units onto planes.
The Honeywell/Safran and L-3/Crane groups are concentrating instead on persuading planemakers to adopt the technology for new aircraft. Their systems drive the main landing gear. Honeywell and Safran expect to run trials with a Safran-owned Airbus A320 by mid-2013. L-3 and Crane tested their team’s unit in December on a Deutsche Lufthansa AG (LHA) A320.
Airlines have powerful incentives to act, said Scott Whitfill, who oversees about 70 tugs as North America maintenance director for Worldwide Flight Services.
“If airplanes were able essentially to back themselves out and I didn’t have to supply a push-back tractor, that would impact the cost of my handling for the airline,” Whitfill said in a telephone interview. “Push-backs are not cheap.”
Savings from the electric motors would be greatest on single-aisle jets such as the A320 and Boeing’s 737, whose frequent short-haul flights mean more time taxiing. Wide-bodies land and take off less often because they fly longer routes.
“It’s huge,” said Rick Jones, vice president of Crane’s aerospace unit. “It’s looking to us like it’s going to be a compelling value proposition for the airlines.”
Davies of Luton, England-based EasyJet is convinced. The carrier’s 215-plane fleet consists entirely of jets from the A320 family. That makes it one of the airlines that would benefit from electric taxi, and it’s preparing to test the Honeywell-Safran system.
“There’s no doubt to me that the technology is there. It will work,” Davies said. “Let’s say 40 years from now, maybe all aircraft will have this.”
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