Page 40 - Volume 17 Number 4

TAMARACK’Sby LeRoy CookIn the technology-hungry, yet conser- vative, world of aviation, innovation is always a welcome topic of conver- sation. Innovators are the people who challenge the status quo, finding a different way of doing things, instead of sticking to the way it’s always been done. We would be missing half the desirable aircraft, avionics and support products we have if someone hadn’t pursued an innovative path.will carry their own weight, and then some – so what’s the downside?The downside of add-on winglets is an increased bending moment in gusts and maneuvers, placing stress at the wing’s root or center section, generated when the ersatz longer wing encounters turbulence or maneuvering loads. Because the wing’s center of pressure moves outboard when adding winglets, it responds with an amplified attempt to flex up or down. To compensate usually requires placing a strap or doubler in the stressed area, unless the designers left in an extra margin of load-carrying ability. These pounds of beef-up structure reduce the useful load and take away some of the winglet’s performance enhancement.When Lockheed extended the wingspan of its L-1011 Advanced TriStar widebody to create the L-1011-500 in the late 1970s, it incorporated active control surfaces to reduce the effect of turbulence on the longer wing structure. Because it was new technology at the time, consider- able FAA resistance was encountered. Now, adding winglets to existing wings also calls for creative solutions.A New WayEnter Tamarack Aerospace; their innovative thinking came up with the notion of pairing retrofitted winglets with small active flight controls,High up in the neck of Idaho at Sandpoint airport (KSZT), Tamarack Aerospace Group has developed a way of retrofitting winglets, with all their attendant advantages, while avoiding the usual necessity for structural beef-up to the airframe.Those no-longer-odd protuberances sticking up from wingtips are well known for fooling a wing into thinking it’s longer than it really is, thereby boosting climb rate and enhancing cruise performance at altitude. Properly designed, they38 • TWIN & TURBINEAPRIL 2013