http://aviadejavu.ru/Images6/HI/HI-16/113-4.jpg Custer Channel Wing aircraft were designed to produce an aircraft that could be flown at a human jogging speed, around 10 kts. The principle involved here is our old mate Bernoulli's - increasing the velocity of a fluid reduces the pressure in the fluid. In this aircraft design, the velocity of the air is created by the rearward acceleration imparted by the pusher propellers located within the semi-circular sections of the wings. The generation of Lift in this manner enables the aircraft to rise from the ground at a very low groundspeed, and vice versa for landing. The channel wing is an aircraft wing principle developed by Willard Ray Custer in the 1920s. Custer's summary of his invention was that the key to the lift created by a wing is the velocity of the stream of air passing over the wing, not the velocity of the airplane itself: It's the speed of air, not the airspeed! A wing functions because the air over the wing has a lower pressure than the air under it. The conventional aircraft must reach a significant minimum speed before this pressure differential become large enough that it generates sufficient lift to become airborne. In Custer's channel wing the rotating propeller will direct a stable stream of air backwards through the channel. A propeller will at the low pressure side normally be supplied by air from all directions. Since the half-tube prevents air from being drawn from below, the air will be sucked through the channel instead. This creates a strong low pressure area in the channel, which again generates a lift. The regular design outer wings do generate lift, but are set at a dihedral for roll stability as is common practice in aircraft design. The concept was shown to work, but although the construction functions very well at relatively low speeds,at higher speeds, at high propeller RPM, oscillations would occur in the areas around the propeller, causing increased noise as well as creating long term destructive vibrations in the structure. The twin layout had a higher risk of loss of control during a single engine failure situation, since the production of lift is dependant on the operation of the propeller. The Baumann Brigadier was chosen by Willard Ray Custer as the basis of his Custer CCW-5, which used the fuselage and tail of the Brigadier. The Baumann Brigadier was a prototype American light transport aircraft of the late 1940s. It was a twin-engined monoplane, which, unusually, was of pusher configuration. Only two were built, plans for production never coming to fruition. Here is Custer speaking about his aircraft on The American TV show "I've got a Secret"
