Page 27 - Volume 14 Number 8

During Travel Air’s brief seven- year existence from 1925-1931, workers built more than 1,450 biplanes and monoplanes. Of these, records indicate about 25-30 were Type BH (later changed to Type 3000). Customers were informed that the company would not build a “Hisso-powered” biplane unless the owner provided the engine, because none were kept in stock at the factory. During 1927-1928 the Type 3000 was flown by Louise McPhetridge von Thaden to establish altitude, speed and endurance records for women aviators. She was the only woman to hold all three records simultaneously, albeit only for a short time.
A Detailed Look at the Hisso
The history of the Hispano- Suiza Model 8A engine harks back to the autumn of 1914 when the Allied powers realized that the German six-cylinder Mercedes aircraft engine was superior to any powerplant being used on airplanes built by England or France.2 In response, a number of European companies attempted to design new engines, but one engineer – Marc Birkight – soon forged ahead of his contemporaries. He was a highly respected and capable engineer at the Hispano-Suiza Company that was well known for its powerful and luxurious automobiles. The company had factories in Barcelona, Spain and in Paris. Birkight, however, was a Swiss engineer and had extensive experience in designing and constructing machine tools. He considered a factory’s ability to manufacture an engine quickly and accurately to be as equally important as its performance. One historian described Birkight as a “... remarkable man. He invented the sports car, built six-cylinder cars that could go 100 mph, yet which
idled so smoothly that a dime could be balanced on the radiator. He made 12-cylinder cars that were better than any Rolls-Royce and designed the first good aircraft cannon, and in 1915 Birkight showed the world how to design and build a water-cooled, 150-horsepower engine.”
Birkight’s creation featured alumi- num cylinder banks with threaded, steel sleeves – a configuration that reduced overall weight, stiffened the crankcase and promoted easier, faster fabrication, manufacture and assembly. A single overhead cam- shaft was mounted on each bank of four cylinders that featured a bore of 4.7 inches and a stroke of 5.1 inches. The engine displaced 718 cubic inches and had a dry weight (less radiator and plumbing for water cooling) of 467 pounds. Moving parts were enclosed and lubricated by a pressure-oil system. Overall, the powerplant was rigid, light, durable and reliable. The engine’s weight was actually less than some static, air-cooled radial engines of the era that normally weighed less than water-cooled powerplants.
The first prototype of his V-8 design was tested by the French army in 1915 and successfully ran under test loads for 15 hours. Two additional engines ran for 50 hours and both passed the army’s stringent tests. These powerplants were capable of delivering 150 horsepower continuously, compared with about 90 horsepower for a majority of aero engines then in use by the Allied nations. Late in 1915 production began at the Paris factory, and the French Government soon ordered design work by other companies to cease and focus on producing the Hispano-Suiza engine.
By 1916, a year before the United States entered the war, contracts were underway to build the powerplant in America.3 Early in 1916 a contract for 450 engines was
AUGUST 2020
KING AIR MAGAZINE • 25