Gallaudet D-1
The two-seat Gallaudet D-1 and its successors D-2 and D-4 are among the most unusual aircraft types in aviation history. The 4-blade pusher propeller sat in the middle of the fuselage and formed a kind of link to the tail of the aircraft.
The Gallaudet drive principle
The fuselage was in two parts. The front and rear parts were connected by a central tube. A propeller hub mounted transversely to the flight direction behind the cockpit rotated around it. The outer ring of the hub corresponded to the outer diameter of the fuselage, which resulted in a flush and aerodynamically favorable lines. Each propeller blade was attached to the hub and passed through an opening in the outer ring. The aircraft was powered by two four-cylinder in - line engines , each with a shaft, mounted side by side . The engines and propellers were connected by a coupling so that the machine could be flown with either or both engines.
Edson Fessenden Gallaudet applied for a patent for his drive system on April 21, 1916, which was granted on April 16, 1918 with the number 1,262,660.
history
Edson Gallaudet taught physics at Yale University between 1897 and 1900 and experimented with flying machines since 1898. The hydro-bike double-decker glider with floating pontoons , for example, dates from this year . In 1908 he founded Gallaudet Engineering in Rhode Island . In 1912 his first airplane appeared, the Gallaudet A-1 Bullet .
In 1915, Gallaudet took part in a US Navy tender for a light airborne observation aircraft. Although his concept D-1 did not win the tender for reasons of cost, he nevertheless received an order to build a machine. The price has been set at US $ 15,000. The aircraft was given the US Navy serial number "A59". It was built at Gallaudet's factory in Norwich, Connecticut .
The D-1 was a double-decker - seaplane with a central float and two water-cooled 150 hp Duesenberg -Flugmotoren. The four-cylinder engines with the walking beam valve control typical of Duesenberg with extra-long rocker arms first had to be developed and delayed the construction of the aircraft. For Duesenberg, they were the first aircraft engines whose design was derived from the successful racing car engine. EF Gallaudet visited the Duesenberg plant in Chicago on February 11, 1916 to oversee the manufacture of the engines. The first engine was delivered at the end of February and the second in mid-March.
The first flight took place on July 17, 1916. The pilot was David McCullach. The machine initially proved extremely difficult to fly and was damaged during the tests. Gallaudet struggled to find a good pilot for the machine. Only the more experienced pilot Filip A. Bjorklund was able to fly the machine properly and gave a number of tips on how to improve the design.
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The engines also caused problems at first. A crack in a piston led to an overhaul of both engines by the manufacturer in October 1916. The engines were also prone to overheating and misfiring; the latter was also attributed to the insufficient water supply. Duesenberg then took the engines back and subjected them to extensive tests and further revision. They were reinstalled at the end of November 1916 without initially being able to completely avoid the misfires. They did not run satisfactorily until January 1917.
In 1917, Gallaudet renamed his company the Gallaudet Aircraft Company . In that year the Duesenberg Motor Company merged with the Loew-Victor Engine Company to form the Duesenberg Motors Corporation (DMC) and moved into new plants in Elizabeth (New Jersey) at the end of 1917 .
In mid-January 1917 the machine was delivered to the Naval Air Station Pensacola . The tests were no longer carried out by the pilot Bjorklund. Navy pilot Philip Rader initially had some difficulties with this unusual type of aircraft. In the tests, the machine showed high speed and stable flight characteristics. The US Navy took over the machine on February 24, 1917 with the serial number "AH-61".
However, it remained with a built D-1, which was further revised at Gallaudet in Rhode Island. At the end of 1917 two new, lighter Duesenberg engines, each with 16 valves, were installed, although the machine had flown satisfactorily with the old engines in the end. It was no longer used by the Navy and was probably scrapped in 1919, after one of its engines had been removed in early 1918 and used as a study object for training purposes.
Gallaudet D-2 and D-4
A Gallaudet D-2 version is also occasionally mentioned with 150 bhp Duesenberg engines, but actually flew with two overhead six - cylinder Hall-Scott A-5a engines with the same power. Four copies of this improved variant of the D-1 were built, which were taken over by the United States Army Signal Corps with the numbers AS429 to AS432 .
The Gallaudet D-4 was a modified D-1 with only one Liberty engine with 400 hp that first flew in 1918. On July 19, 1918, the pilot Arthur F. Souther had a fatal accident with her. The second D-4 also flew from 1918 and even took part in the Curtiss Marine Trophy Race in September 1922.
Technical specifications
| Parameter | Gallaudet D-1 | Gallaudet D-2 | Gallaudet D-4 |
|---|---|---|---|
| crew | 2 | ||
| length | 10.06 m | 10.21 m | |
| span | 14.63 m | 14.16 m | |
| Takeoff mass | 2021 kg | ||
| Max. Takeoff mass | 2321 kg | ||
| Top speed | 148 km / h | 191 km / h | |
| Number Engines | 2 | 1 | |
| Engines |
Duesenberg 4-cylinder water-cooled |
Hall-Scott A5a 6-cylinder water-cooled |
Liberty L-12 12-cylinder water-cooled |
| power | 2 × 150 hp | 360-400 hp | |
literature
- William Pearce: Duesenberg Aircraft Engines: A Technical Description. Old Machine Press, 2012, ISBN 0-9850353-0-7 .
- Don Butler: Auburn Cord Duesenberg. Crestline Publishing Co., Crestline Series , 1992, ISBN 0-87938-701-7 .
- Fred Roe: Duesenberg - The Pursuit of Perfection. Dalton Watson Ltd., Publishers, London W1V 4AN, England, 1982, ISBN 0-901564-32-X .
- Griffith Borgeson : The Golden Age of the American Racing Car. Edited by SAE (Society of Automotive Engineers), Warrendale PA, 2nd edition, 1998, ISBN 0-7680-0023-8 .
Web links
- Gallaudet D-1
- Gallaudet D-1
- Edson Fessenden Gallaudet
- Images Gallaudet D-1 and D-4
- Aerofiles, American airplanes GA-GO
- Dennis Simanaitis: Edson Gallaudet's Glorious Flying Machines.
- Dennis Simanaitis: 1916 Gallaudet D-1 seaplane - The Tradeoffs of Innovation.
- U.S. Patent 1,262,660 issued April 21, 1916; EF Gallaudet: Airplane.
Individual evidence
- ^ A b c Dennis Simanaitis: 1916 Gallaudet D-1 seaplane - The Tradeoffs of Innovation.
- ↑ U.S. Patent 1,262,660, issued April 21, 1916; EF Gallaudet: Airplane.
- ^ Dennis Simanaitis: Edson Gallaudet's Glorious Flying Machines.
- ↑ a b c Butler: Auburn Cord Duesenberg. 1992, p. 61.
- ↑ a b c d e f Pearce: Duesenberg Aircraft Engines. 2012, pp. 36–38.
- ^ Butler: Auburn Cord Duesenberg. 1992, p. 76.
- ↑ AeroFiles: Gallaudet.