Meet United’s New Fuel-Saving ‘Split Scimitar’ Winglets

If the wing on your future United Continental Holdings Inc.UAL -0.20% flight seems to have sprouted an extra tip, don’t be alarmed: it’s the aviation industry’s newest effort to save money.

Jetliners have long sported winglets, the aerodynamically crafted, upswept wingtips that minimize drag by reducing the miniature tornadoes that occur at the ends of airplane wings because of differing pressure above and below.

Now United is introducing “split scimitar” winglets into passenger service. The first 737-800 in United’s fleet of 258 737s was fitted with the new wingtips this past weekend, and the first flight is today, from Houston to Los Angeles.

The radical re-sculpting of traditional winglets adds a new tip below the upturned one that sharply curve backwards like a scimitar. That further reduces wingtip vortices that drag on the wingtips.

Each traditional pair of winglets on the 737 cuts fuel consumption by 3.5% to 4% on flights of more than 1,000 nautical miles. The split scimitar upgrade—which costs $545,000, before discounts–will reduce fuel burn by up to 2% more, says United, which hopes to save up to $60 million a year because of the devices, once its fleet is outfitted.

A United Airlines employee installing a new winglet on a jet in Orlando this week. 

“One of the problems is that these designs look a lot different and people say ‘oh those look kind of weird and stuff,’” says Joe Clark, chief executive of Aviation Partners Inc., the Seattle company that pioneered original upward-swept winglets and has developed the split scimitar. “But if it really works well, the weirdness goes away fast.”

Aviation Partners debuted its winglets on 737 business jet in the late 1990s. Today, thanks to airline demand, virtually every 737–Boeing’s most popular single-aisle jet–is fitted with winglets.

Airlines have gotten increasingly creative to save fuel costs. Delta Air Lines Inc. in 2012 agreed to buy an oil refinery. One Japanese airline suggested passengers empty their bladders before boarding. Other airlines have removed in-flight magazines and some have replaced paper aeronautical charts with tablets.

United is in the process of cutting its annual costs by $2 billion, through a series of initiatives, including the new wingtips. The airline spent $12.3 billion on aircraft fuel in 2013, down 6% from a year prior.

United fleet Vice President Ron Baur says the airline will have its fleet of 130 737-800s outfitted with the scimitars “as fast as we can” over the next 12 months, and will fit its smaller and larger 737 models later on.

United says it saves $200 million in fuel each year because of the winglets on its 737s, and larger 757 and 767 jetliners. Mr. Clark says Aviation Partners has begun studying outfitting split scimitars on both larger jets as well.

Other U.S. carriers are on board. Alaska Air Group Inc. and Southwest Airlines Co., two of the airlines most reliant on BoeingBA -0.99% 737s, have signed up to install the split scimitar winglets on their fleets of larger current-generation 737s.

Mr. Clark says Aviation Partners Boeing, its joint venture with the plane maker, holds orders and options for upgrade kits for around 1,500 737s. He hopes to have 5,000 jets with this technology flying in the next five to seven years.

The new design also presents a new challenge to airlines. The downward-facing fin is vulnerable to damage from vehicles that move around airports. United is training its ramp agents to work carefully around the new wingtips and has emblazoned the word “scimitar” on the underside of the nose to alert those working around the jet.

“The fuel savings is so great, we’ll take that risk,” said Mr. Baur.

Fonte: http://blogs.wsj.com/