For many years, a small company named Lam Aviation has showcased its variable-geometry wing design at EAA AirVenture. Company founder Lawrence Lam (who passed away in 2010) even designed and built his own low-wing, retractable gear, single-engine airplane–the Wanderer–to demonstrate the concept and flew that airplane to Oshkosh three times.
This year Larry’s son Michael, CEO of Lam Aviation, is bringing a modified Lancair Columbia to Oshkosh to highlight the Lam aileron’s benefits and, hopefully, generate some interest from manufacturers that would like to incorporate the design in their airplanes.
The modified Columbia, which is parked next to the Innovation Pavilion, has basically been re-winged. Engineer Greg Cole, founder of Windward Performance, designed the new Columbia wing incorporating the Lam ailerons. Windward Performance and Lam Aviation are both located at Bend Municipal Airport in Oregon. Cole is also designing the Perlan II glider, which will attempt to set a world record by climbing to 90,000 feet, and will be answering questions about the Lam system, along with test pilot Len Fox, at the Lam exhibit at the Innovation Pavilion.
There are two key differences on the Columbia’s new wing: first, it is 20 percent smaller than the stock wing (although it contains the same amount of fuel). And second, the wing is equipped with the Lam aileron design, which includes full-span flaps and ailerons that only move up.
The reason for converting the Columbia 300 to the new wing, Lam explained, is “so we can show before-and-after improvements.” Results so far show a significant performance improvement including: 12 to 16 knots faster cruise at equivalent power settings; 20 to 30 percent less fuel consumed and corresponding range increase at equivalent airspeeds; 40 to 50 percent greater rate of climb; useful load 200 pounds higher; and higher roll rate with lower stick forces, with improved roll authority and handling characteristics at slow speeds.
The new aileron design, according to Lam, “uncoupled the relationship between flaps and ailerons.” The Lam system allows the ailerons and the flaps to be sized independently. On traditional designs, the flaps take up a certain amount of the wing’s trailing edge, and the rest of the trailing edge is available for the ailerons. The smaller the ailerons, the less effective they can be, and the same is true of the flaps.
Traditional differential ailerons, in which one side moves up while the other side moves down, cause adverse yaw, which must be compensated for by adding rudder in the direction of the turn. With one Lam aileron only moving up to roll the airplane, Lam said, “that kind of optimizes the adverse yaw business.” And that aileron can be sized to provide the desired handling and slow-flight characteristics, without worrying about the size of the flaps. And the flaps can extend for the length of the wing if that helps the airplane fly better at slow speeds and thus take off and land at slower speeds.
There is another opportunity with Lam ailerons and that is using the ailerons for more than roll control. Moving both ailerons up at the same time would provide a speed brake effect. Lam also envisions modulating the ailerons to act as spin-recovery devices in case the pilot doesn’t correctly manipulate the flight controls during a spin. The optimal use of Lam ailerons would be with fly-by-wire flight controls. “That would be the ideal platform,” Lam said. “There are all different kinds of things we think could be scheduled into this with fly-by-wire, and that would make it even more efficient and more useful.”
Of course, merely adding Lam ailerons (with new flaps) to an existing wing would add only the slow-speed benefits. Adding a new wing like that on Lam’s Columbia shows quite a bit of performance improvement. But the tail is sized to the wing, so a properly designed Lam aileron airplane could have a smaller empennage and would thus perform even better, according to Lam. “We’ve actually left quite a bit on the table, even with this airplane.”
Lam said that some manufacturers, mostly smaller companies, are interested in the aileron. “Larger companies are more conservative,” he said. “They want to wait to see what everybody else thinks and see an actual airplane, which is important in aviation.” He is open to any kind of licensing or even an exclusive arrangement, but mostly, he said, “I’d like to see it reach as many people as possible. This is a business, [but] at the same time it’s my father’s legacy and this is what his whole life is represented by, and I’d like to see that be recognized as well.”
