Uppercu-Burnelli GX-3
| Uppercu-Burnelli GX-3 | |
|---|---|
|
|
| Type: | Test aircraft |
| Design country: | |
| Manufacturer: |
Burnelli |
| First flight: |
1929 |
| Number of pieces: |
1 |
The Uppercu-Burnelli GX-3 was a test aircraft from the American manufacturer Uppercu-Burnelli. The machine was a contribution to the Guggenheim Safe Aircraft competition held in 1929 . It should serve as a prototype reduced in scale 1: 3 for testing new construction elements that increase flight safety. The construction of a three-engine transport aircraft was planned as a full-scale application. However, this project could not be realized.
history
While working on the CB-16 , Burnelli was already working on another construction that also used the lifting fuselage concept. In addition, he used his invention, patented in 1930, of a mechanism for changing the profile depth ( variable-camber , English for changeable profile center line , see also definitions of profile parameters ). Other elements were also tried to improve controllability, such as small aileron-like control surfaces under the wing and rotating wing end plates.
The millionaire Daniel Guggenheim had set up a foundation with the aim of promoting American civil aviation as a means of transport for people and cargo. The Guggenheim Safe Aircraft Competition was announced in 1927 with the aim of making a significant advance in flight safety by improving the aerodynamic properties of heavier-than-air vehicles without reducing the practical quality of current aircraft . A total of 27 manufacturers (according to other sources only 15) took part in the competition with their own designs.
The GX-3 was built by Uppercu-Burnelli Corp. at the Aeromarine-Klemm Corp. plant in Keyport, New Jersey; it had the serial number 10. Occasionally it was also referred to as Uppercu-Burnelli UB SS.
The GX-3 arrived at Mitchel Field too late to take part in the comparison flights for the competition. However, it is reported that her STOL skills were said to have been excellent. The speed range in which the machine could operate was also impressive with a maximum value of 220 km / h and a landing speed of only 50 km / h.
construction
The GX-3 was a twin-engined mid-decker that was designed by Burnelli based on the lifting fuselage concept. It was the first twin-engine aircraft with lift flaps extending over the entire span and a technical device for changing the profile depth and curvature during flight. The latter was achieved with a fixed wing center section between the front and rear spars and with the movable wing nose and trailing edge. The leading edge of the wing could be lowered by 35 ° and the trailing edge by 30 °.
Two technical approaches were tested to increase controllability and stability around the vertical axis. On the one hand, these were additional ailerons attached under the wing ends and, on the other hand, end plates installed on the wings and on the elevator, similar to today's winglets in the wingtip fences . These were rotatably attached to pipes protruding from the wing box.
The landing gear, which was housed in streamlined fairings, was also unusual. Each case carried two wheels in tandem, with the front wheel smaller than the rear. The two 66 kW (90 PS) engines were installed at the outermost “corners” of the fuselage.
The two pilots sat in an open cockpit behind or between the engines.
Technical specifications
| Parameter | Data |
|---|---|
| crew | two |
| Passengers | - |
| length | 7.90 m (26 ft) |
| span | 14.90 m (49 ft) |
| height | 2.85 m (9 ft 4 in) |
| Wing area | 20 m² (216 sqft) |
| Empty weight | 745 kg (1640 lb) |
| Takeoff weight | 1180 kg (2590 lb) |
| Landing speed | 50 km / h (30 mph) |
| Top speed | 220 km / h (135 mph) |
| Engines | 2 × American ADC Cirrus III piston engines, each with 66 kW (90 PS) |
See also
literature
- Howard Levy & Richard Riding: Burnelli's Lifting Fuselages , Airplane Monthly April 1980, pp. 173f.
Web links
- Photos of the machine (accessed December 23, 2008)
- Text of an article from Vintage Airplane, July, 1992 (accessed December 23, 2008)