Burnelli GX-3
The Uppercu - Burnelli GX -3 was an experimental aircraft of the U.S. manufacturer Uppercu - Burnelli. The machine was a contribution to the held in 1929 Guggenheim Safe Aircraft Competition. It should serve as a scale of 1:3 scaled prototype for testing new, flight safety enhancing design elements. As a full scale application of the construction of a three -engined transport plane was provided. However, this project could not be realized.
History
During the work on the CB- 16, Burnelli busy with another construction, which also used the Lifting Fuselage concept. In addition, he sat for the first time in 1930 his patented invention of a mechanism to change the tread depth of a (variable - camber, Eng. Changing system profile center line, see also definitions of the profile parameters). It also further elements to improve the controllability were tested, such as small aileron control surfaces similar under the wing and rotary Flügelendplatten.
The millionaire Daniel Guggenheim Foundation had launched that had the promotion of American civil aviation as a means of transport for people and cargo to the destination. The Guggenheim Safe Aircraft Competition was announced in 1927 with the aim to achieve a significant advance in aviation security by the aerodynamic characteristics of heavier- than-air vehicles can be improved without reducing the already achieved practical quality of the current aircraft. In total, 27 manufacturers (according to other sources only 15) participating in the competition with their own designs.
The GX -3 was built by the Uppercu - Burnelli Corp.. in the work of Aero Marine Terminal Corp.. Keyport (New Jersey); she wore the serial number 10 Occasionally it was also referred to as Uppercu - Burnelli UB SS.
The GX -3 arrived too late on the Mitchel Field, to participate in the test flights for the competition. However, it is reported that their STOL capabilities, said to have been excellent. Also the speed range in which the machine could operate was impressive with a maximum value of 220 km / h and a landing speed of 50 km / hr.
Construction
The GX- 3 was a twin-engine, mid-wing aircraft, which was designed by Burnelli using the buoyancy hull concept ( Lifting Fuselage ). She was the first twin-engine aircraft with over the entire span reaching lift flaps and a technical device for changing the profile depth and buckle during the flight. The latter was achieved with a fixed wing center portion between the front and the rear spar, and the movable wing leading and trailing edge (see diagram ). The leading edge of the wing could be lowered by 35 ° and the rear edge 30 °.
For increasing the controllability and stability to the vertical axis two technical approaches have been tried. Once these were mounted under the wingtips additional ailerons and other installed on the wings and the elevator end plates, similar to today's winglets at the wingtip fences execution. These were mounted rotatably on protruding from the wing box tubes.
Unusually, the undercarriage, which was housed in streamlined fairings. Each housing bore, two wheels arranged in tandem, wherein the front wheel was less than the rear. The two 66 kW ( 90 PS) payable engines were installed at the extreme "corners" of the hull.
Behind and between the engines were the two pilots in an open cockpit.