From Boeing's website:
By using wing tips, the 767-400ERs are achieving a 4 to 5 percent fuel efficiency improvement. That equals a savings of 1.3 million pounds of fuel per year, per airplane and 4 million pounds of CO2 - the global warmer. The 4 to 5 percent fuel reduction in dollars adds up to between $196,000 and $245,000 fuel savings per year per airplane. "It seems incredible that a couple of 135-pound wing tips would be able to do all that," Weertman said.
Boeing eventually secured two U.S. patents on the raked wingtip designs.
The 767 has always been known as the airplane of innovations, and the raked wingtips continue that tradition," Weertman said. "In every dimension, what we ended up with was better. For us, it became a very easy decision."
Wing Tip Facts
Wing tips produce up to 5 percent fuel efficiency improvement or 1.3 million pounds of fuel savings per year resulting in an average of $200,000 savings to airplane's operator.
They reduce 4 million pounds of the global warming CO2.
Each wing tip weighs only 135 pounds, but helps to create 10,000 pounds of lift.
Installation or removal of the wing tips takes about 30 minutes.
The 7-foot-long raked wingtips are made at Boeing's Frederick, Wash., site, of an external, light-weight composite material and supported internally by aluminum spars.
Sixteen bolts connect each wingtip to the rest of the wing structure.
The 767-400ER can be flown with or without the wing tips.
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