Seattle: They have become a familiar sight on one of the world's most popular commercial jets—large sail-like structures at the end of the wing that gracefully curve up towards the sky.
The blended winglets, developed by Aviation Partners Inc., a small Seattle company, have helped transform an industry that is looking for all things “green”. The winglets improve fuel burn and help big jets be more efficient.
They are on some 2,500 Boeing Co.’s planes, mostly the single-aisle 737s.
And someday they could be on the Airbus A320 family of single-aisle planes, too. The A320 and 737 families are the most frequently flown commercial jets around the globe.
“We are in a green revolution today and we have a great solution. Our winglets are the best fuel hedge that an airline can get,” said Joe Clark, one of the founders of Aviation Partners, after his company and Airbus SAS announced that blended winglets will be tested on an A320.
Interestingly, Boeing would profit if the tests prove successful and Airbus decides to offer the winglets as an option to customers, as Boeing does now for customers who order its 737s.
Clark said Boeing has helped Aviation Partners pioneer the technology. A new company would likely be formed to provide the technology for Airbus, Clark said, and Boeing would have a financial interest in that company.
“But we have not even discussed those kinds of things,” Clark said. “We are still in the technical stage. We are a long ways from getting blended winglets on an Airbus plane.” He said the Airbus trials may take about three months. Clark said the winglets designed for the A320 are unique to that plane, though they look similar to those on the 737.
Even though Clark's company and Boeing have worked closely over the years, and formed a joint venture called Aviation Partners Boeing, Clark said the joint venture has nothing to do with the work his company is doing with Airbus. He used the analogy of GE engines, which are found on both Boeing and Airbus planes.
Aviation Partners was established by Clark and Montana businessman Dennis Washington in 1991. The idea took root when Washington called his friend Clark and asked Clark to explore the possibility of extending the range of Washington's Gulfstream II. Clark gathered a team of mostly retired Boeing and Lockheed Martin Corp. engineers and flight-test department heads. They included Louis Gratzer, a University of Washington professor of aeronautics who had once been chief of aerodynamics for Boeing.
Clark called the bunch his “dream team”. “They were all just waiting around to play tennis,” Clark quipped in a 1999 interview. “We harnessed some marvellous Boeing talent.” The winglet, the team designed, reduced the drag on Washington's Gulfstream II by more than 7%. The winglets work by reducing drag created by the vortices that are generated by a plane's wingtips.
By 2014, Aviation Partners Boeing estimates that blended winglet technology will have saved the airline industry more than 5 billion gallons (22.5 billion litre) of jet fuel. Winglets were common on business jets before Aviation Partners took an interest.
But those traditional winglets, which also are found on all Airbus models and the Boeing 747-400, rise at a sharp angle from the wing. Blended winglets gently curve up, as if they are part of the wing.
Winglets were first developed by the National Aeronautics and Space Administration, or Nasa, in the 1960s to help reduce drag. Increasing the wingspan can produce the same results. But jetliner wings can't get any longer and still fit at airport gates. That's why Boeing decided to put a traditional winglet on its 747-400.