A Seattle-based aviation company, Aviation Partners, whose major product has become a familiar sight at airports around the world has asked a Texas federal court to dismiss a lawsuit filed by European planemaker Airbus.

That suit asks the court to invalidate patents granted Aviation Partners for its “Blended Winglet” technology. Those winglets are the curved extensions that many aircraft now sport at the end of their wings.

Those winglets reduce drag, save fuel and increase the range of airliners on which they are installed. Almost all new Boeing 737s are equipped with those winglets now.

Airbus filed the suit because they expected a challenge by Aviation Partners to Airbus’ design and use of similar winglets that Airbus calls “Sharklets” on the ends of the wings of Airbus aircraft.

Aviation Partners and Airbus had signed an agreement several years ago to share Aviation Partners’ technology for use on Airbus planes, but Airbus created its own design instead.

Aviation Partners contends that design is a close copy of their patented “Blended Winglet.” Historically Airbus’ A320 aircraft were equipped from the assembly plant with an arrowhead-shaped device called a wingtip fence designed to do the same job as the blended winglet. The blended design, however, proved better at saving fuel than the fence.

Here are examples of Airbus’ sharklets and Aviation Partners’ blended winglets. The sharklets are installed on the Airbus plane. The blended winglets are installed on a Qantas Boeing 737.