World War I Aircraft

By Alan Smith

The Curtiss JN-4 ‘Jenny” that trained U.S. Army pilots prior to their travel to France to fly French fighter aircraft. (Photo byBrian Karli at Amarillo Texas in 1918/Holcomb’s Aerodrome)When gunfire began in the First World War, the airplane was just 11 years old and had been in competition for five years. In America, however, the airplane was still an aerodynamic juvenile. No one had thought about using it to wage war. That would quickly change.

The Europeans had moved far ahead of the U.S. in aircraft design and manufacturing, largely due to the willingness of their governments to invest in aviation. In 1913, for example, the French allocated $7.4 million for aircraft development while the U.S government spent a mere $125,000. As a result, during the opening years of World War I the American aviators were still flying fragile Wright and Curtiss pusher biplanes. While European designers were busy developing relatively high-performance combat aircraft, American exhibition pilot Lincoln Beachey and race car driver Barney Oldfield were amusing spectators by chasing each other around dirt racetracks. It was almost as though Americans had not yet figured out what an airplane could be used for.

When the U.S. entered the war in 1917, there was no time to catch up in aircraft design. While American pilots were being trained on another Curtiss design, the JN-4 “Jenny” (powered with a 90 hp OX-5 engine), the government purchased combat aircraft from French manufacturers. One of the most popular was the S.P.A.D. “chasseur” (pursuit).  When American squadron pilots arrived in France, they simply took delivery of their combat aircraft and upgraded their skills with a few practice hours.

The war produced two major advancements in aeronautical engineering: The air-cooled radial aircraft engine and the self-supporting cantilevered wing. The early radial aircraft engines were rotary engines: The engine and propeller were one unit and rotated around a crankshaft secured to the engine compartment firewall. One purpose of this design was to use centrifugal force to get lubrication out to the valve gear in the cylinder heads. The throttle had two positions: closed and full power. The pilot used an ignition interrupter button for intermittent power to start a dive on enemy aircraft and to slow for landing.

This rather hit-and-miss concept gave way quickly to the air cooled carburetor radial engine we know today. In the U.S., most of these engines were built by the Pratt & Whitney, Curtiss Wright and Kinner companies.

A Fokker triplane circa 1917. This type was flown in combat by baron Manfred Von Richtofen. He was known as the “Red Baron” in his triplane finished in red.The cantilevered wing with internal strength provided by a main spar with the strength characteristics of a construction I-beam was developed by Dutchman Anthony Fokker, a major builder of combat aircraft in Germany. The self-supporting wing was first used in the Fokker DR-1 triplane. After a test flight of the first DR-1, with lightly structured wire braced wings, led to a fatal crash due to wing failure, Fokker and his engineers returned to the drawing board to create a wing of self-sustaining strength. The new triplane was successfully test flown without any outer-wing struts or wire bracing. However, high-ranking military decision makers refused to believe what they saw and insisted on outer wing bracing. To get the order, Fokker sighed and put struts in even though he had proved them unnecessary.

Both the new engines and the high strength wing laid the foundation for The German Fokker D-VII was thought to be the best fighter of WW I. It was powered by both Mercedes and BMW engines.the monoplane. Another important device was developed by Fokker’s engineers. It was a mechanical coordinator that would allow a machine gun to fire through the spinning propeller of a running engine without the risk of damaging the propeller. This allowed guns to be mounted on the nose directly in front of the pilot and improve his aim at a flying target. Previously, machine guns had to be mounted on the top wing and were fired with a cable extending down into the cockpit.

As the war went on, performance of the European fighter aircraft improved. Aerial combat was, after all, a form of competition as pilots sought to get and keep control of the airspace over the trench scarred battlefields. In early 1918, Anthony Fokker came up with his D-VII model. It was a strong biplane powered by both BMW and Mercedes engines. The The Fokker DR-1 triplane, the first aircraft to have cantilevered wings. The outer Wing struts seen are unnecessary. Anthony Fokker’s achievement made the streamined monoplane possible.BMW version had a top speed of 124 mph. That was fast for 1918. For most of the war, the parachute was unknown. This lifesaver was only used by barrage (observation) balloon crews. They could escape when attack set the hydrogen filled balloons afire. Battles between fighter pilots were often duels to the end of life for one or, in a few cases, both.

In England, British designer T.O.M. Sopwith came up with both a biplane and a triplane. The biplane was nicknamed the “Camel” because of the humped cowling over the nose mounted synchronized guns.

As the war came to an end, Fokker and many of his people, along with a trainload of D-VII fighters and equipment escaped back to Holland where work on aircraft design continued. The Fokker D-VII appeared in the Dutch Air Force, while Fokker and his crew turned their attention to transport aircraft, supplying tri-motors to both European and American fledging airlines. In 1922, he moved to the United States and became an American citizen. He established the Atlantic Aircraft Corporation and The world’s first aircraft carrier? The HMS Prgasus. Taken in 1918, it shows a Sopwith Camel taking off to attack enemy airships with the Lewis gun mounted on the top wing. continued building transports. He died in New York in December 1939 at the age of 49.