| Model 8000 | |
|---|---|
| General information | |
| Type | General aviation |
| National origin | United States |
| Manufacturer | Travel Air |
| Number built | 3 |
| History | |
| First flight | 1927 |
| Developed from | Travel Air Model B |
The Travel Air 8000 was an American general-purpose biplane of the 1920s, a member of the family of aircraft that began with the Travel Air Model A. [1] It was also known as the Travel Air 4000-CAM, [2] and later as the Curtiss-Wright CW-8 after Curtiss-Wright acquired Travel Air. [3] Only three examples were built. [4]
Like other members of this family, the Model 8000 was an unequal-span, single-bay, staggered biplane of conventional design. [4] The passengers and pilot sat in tandem, open cockpits. [4] It had a conventional tail, and fixed, tailskid undercarriage. [4] The fuselages were built from welded steel tubes, and the wings from wood. [5] Travel Air model numbers primarily reflected changes in powerplant, and the Model 8000 was powered by a Fairchild-Caminez 447 radial engine mounted in the nose, driving a tractor propeller. [6]
The prototype Model 8000 was a re-manufactured Travel Air Model B. [2] [7] Its engine was an innovative design that used a cam in place of a crankshaft. [8] [9] The result was an engine that was mechanically simpler [9] and which ran at half the RPMs of a conventional radial engine for the same power, [2] promising greater efficiency. [8] The low RPMs needed a larger propeller, [2] 10 feet (3.0 m) in diameter, [10] compared to the 8-foot-4-inch (2.54 m) propeller of the Travel Air 2000. [11] In turn, the larger propeller needed more ground clearance, which meant that the whole powerplant had to be mounted higher on the Model 8000's nose. [8]
Despite much enthusiasm for the new engine among American manufacturers, it did not work well. [8] It was prone to excessive vibration, even to the point of splitting propellers, [2] it ran hot because the large propeller hubs needed to absorb its torque also blocked cooling air from the cylinders, [10] and that torque also twisted airframes. [10]
It proved very difficult for Fairchild-Caminez to get the engine operating reliably enough to pass certification. [2] By the time this was achieved, in June 1928, [2] the Model 8000 itself had already received type certificate ATC-37 in April. It would be the only aircraft type certified to use this engine. [8]
Beside the prototype, only two other examples of the Model 8000 were built, and no details about them other than one construction number have been preserved. [4]
The problems with the engine proved insurmountable, [8] and development was abandoned in fall, 1928. [9] It was withdrawn from sale, [8] and Fairchild Aircraft founder Sherman Fairchild offered customers their money back. [12]
By March 1929, the Fairchild-Caminez engine was removed from the prototype Model 8000 and the aircraft was converted into a Travel Air 2000. [4]
Fairchild Aircraft purchased the prototype, and entered it in the 1928 Ford National Reliability Air Tour [2] together with a Fairchild-Caminez 447-powered Waco 10. [13] Flown by James Nelson Kelly, the Model 8000 finished in thirteenth place [14] [15] out of a field of twenty-five, requiring several engine changes. [2]
Data from Phillips 1994, p.106
General characteristics
Performance