Winglet Technology says its Cessna Citation X elliptical winglets will be certificated by June 2009 after more than a year of testing by Cessna.

The $395,000 retrofit kit, not including installation, will provide a 15kt (28km/h) speed increase at altitude, an additional 545kg (1,200lb) take-off performance at hot and high airports or an increase in range of up to 280km (150nm). Along with a reduced time to climb, the graphite epoxy winglets will generate a reduction in fuel consumption by 4-5% for long-range missions.

Fort Felker, vice-president of engineering for Winglet Technology, says modifications will be carried out at Cessna service centres, where maintainers will reinforce the four outer bays of the wing to support the additional structure. Unlike Aviation Partners blended winglets, the elliptical design spans the full width of the wingtip and is curved at all points along the structure versus a straight winglet that is connected to the aft portion of the wing and blended into the wing using a radius.

The difference, says Felker, is lower loads on the aft spar of the wing and improved aerodynamic performance. Winglet Technology is also in the running to supply winglets for Beechcraft's Premier II, due for first deliveries in mid-2010.

The company is also developing methods to actively control winglets to decrease the need for structural reinforcements for winglet installations, thereby further increasing fuel economy and performance benefits.

Source: Flight International