A fuel-saving angle for cargo
United Airlines consumes 4 billion gallons of oil per year, says James Larson, senior manager of fleet strategy and planning at United Airlines. He estimates that this is about 1 percent of the world’s oil supply.
“We’re always looking for ways that we can mitigate and minimize our exposure to fuel, especially fluctuating fuel prices, and obviously one way to do that is to reduce your total consumption. So winglets help do that,” Larson says.
United has the blended winglet on all of its 737s and many of its 757s and 767s. It first began using winglets in the mid-2000s.
Earlier this year, United was the launch customer for the split scimitar winglet, which promises up to an additional 2 percent fuel burn savings for each aircraft.
United is retrofitting its 737s with the split scimitar winglet.
“We’re strong believers in winglets,” Larson says. “Being a launch customer is more than just being the first to take delivery of a winglet. We’re involved in some of the flight testing that goes on for getting the winglets ready to go and certified.”
Southwest Airlines, which began using winglets in 2003, is installing the split scimitar winglets on 33 new 737-800s once they are delivered to the airline this year. The airline also plans to retrofit 52 737-800s.
All of Southwest’s Boeing 737-700s and 737-800s, as well as a majority of its 737-300s, use blended winglets. More than 75 percent of the carrier’s fleet has winglets.
Dan Landson, a spokesperson for Southwest, says winglets help save the airline 54 million gallons of fuel every year.
“It saves on how much we have to charge our customers, so it’s a trickle-down effect,” he says. “The investment costs that we use to put on the winglets, we make it back in terms of savings.”
Landson also points out the environmental effects.
“The winglets actually help us reduce emissions,” he says. “Reducing emissions, reducing the fuel usage, all that helps us support our commitment to the environment.”
The future of winglets
No one interviewed by Air Cargo World disclosed the price of a winglet or the price to install one.
Nonetheless, GKN Aerospace is studying how to lower manufacturing costs for winglets with its UK research program Structures Technology Maturity (STeM). STeM’s project looks at using a robotic machine to lay up the carbon material of which winglets are made; usually, many people are required, Gear says. This makes the winglet cheaper to produce.
At Bombardier, researchers have made a new winglet design with an increased canted angle, resulting in a winglet that is almost straight across. Bombardier’s new winglet has a 40-degree angle instead of the typical 15-degree angle, Viau says.
Bombardier is also using a beaver tail winglet design, which makes the blending between the wing and the winglet more aerodynamically efficient.
As for the future, manufacturers and airlines predicted greater usage of winglets.
“Winglets are here to stay,” Gear says. “They may change in their profile and shape, but the point of the end of the wing developing savings for the overall aircraft performance, is here to stay and will become commonplace on all future aircraft.”