Weber and Dietrich Küchemann around 1955. Their team at the Royal Aircraft Establishment (RAE) noticed that delta wings generated large vortexes over the wing when flying at low speeds and high angles of attack ("alpha"). Specifically, the vortexes increased the speed of the air on top of the wing, thereby greatly increasing lift at low speeds. This effect was magnified by the length of the wing, and the sharpness of the angle of the leading edge - more sweep led to stronger vortex creation, more length gave it more room to operate over. This suggested that an aircraft with a delta wing running the majority of the length of the fuselage at very great sweep angles, over about 65 degrees, would have reasonable low-speed performance while also keeping the supersonic drag to a minimum through its limited span. A major concern was the angles needed to generate these vortexes. The aircraft would have to fly at what would be considered significantly nose-high attitudes, especially on takeoff and landing. They would also need very long landing gear, especially in the nose, in order to keep the wing at a high angle during the takeoff roll. This led to some questions about the handling and control of such a design at low speed. According to aviation author C. H. Barnes, one source of scepticism for the configuration came from a series of wind tunnel tests that had been performed in America, but were later determined to have been misleading. Glider At the first meeting of the Supersonic Transport Committee in 1956, the need for a dedicated low-speed testbed aircraft was decided to be paramount. As the envisioned test aircraft was only required to fly at very low speeds, it had been originally decided that an unpowered glider would be sufficient. This determination had led to an official specification being formulated after an outline for such an aircraft had been submitted by Slingsby Sailplanes. Development of this glider was awarded to Slingsby, who commenced work on the Slingsby T.48 thereafter. However, after the operating costs involved in the test programme were reviewing, it was forecast that a powered version would achieve 200% more flying time at 95% less cost per hour. Each flight with the glider required it to be towed by an aircraft, such as the English Electric Canberra bomber, to a relatively high altitude of around 30,000 ft (9,140 m). Furthermore,