“…with a rising shriek, the speed began to rise rapidly and large patches of red heat became visible. The engine was obviously out of control. All the personnel went down the factory at high speed in varying directions…”
—Sir Frank Whittle, describing an early test of his gas turbine design
Today, the gas turbine is known for making high-speed, efficient flight a reality. Its output can range from a few horsepower to tens of thousands. Whether it is a turboprop or a turbojet, it has proven itself to be far superior to its piston forebears in every area except one: cost of acquisition.
Despite that barrier, the gas turbine has been increasingly utilized in General Aviation for nearly 40 years in single and multi-engine aircraft. But it may never have existed if it hadn’t been for the persistence of two inventors—one British and one German—in the years immediately preceding World War II.
Ironically, the invention that could have potentially furnished military superiority was ignored early on by military leaders of both countries.
“It’s a gas turbine and gas turbines are impracticable”
Englishman Frank Whittle had come up with the seminal idea for a turbine engine in 1929 when he was serving as an RAF pilot. He proposed a powerplant that would use burned gases directed through a nozzle to produce thrust.
Further, he reckoned, a projected speed of 450 knots or better was possible—actually necessary—at rarefied altitudes where low density would greatly reduce surface drag.
It was a brilliant concept, at least on paper, and Whittle lacked but one ingredient: capital to develop the engine. Even though its primary use was bound to be military, the peacetime British government wasn’t interested.
“We had to struggle through a morass of skepticism,” he wrote in a 1989 article in Rolls-Royce Magazine. “It was based on the dictum that it’s a gas turbine and gas turbines are impracticable.” He nonetheless patented the concept in 1930 and managed to raise a dribble of money among friends and relatives.
In 1936, he founded Power Jets, Ltd. at Rugby and received grudging permission from the RAF to continue research on a part-time basis—as long as it didn’t take more than six hours a week from his job as an RAF instructor.
An easier sell in the Third Reich
Meanwhile, as Germany powered up its air power toward its ultimate goal of world conquest, almost any new idea that could help achieve that quest was being given consideration. A bright young engineer named Hans von Ohain had independently originated virtually the same thesis as Whittle’s, and approached aircraft manufacturer Ernst Heinkel with his proposal.
By April 1936—about the time Whittle founded Power Jets—Ohain began work on an experimental engine, and although it was a totally different approach than that of Whittle’s, had an operational unit within a year.
In contrast, Frank Whittle continued the slow and frustrating process of refining his design. On April 12, 1937, a prototype made its initial run. After an electric motor spun the engine to 2,000 rpm, Whittle opened the control valve.
“For a second or two the speed of the engine increased slowly and then, with a rising shriek like an air-raid siren, the speed began to rise rapidly and large patches of red heat became visible on the combustion chamber housing,” he explained.
“The engine was obviously out of control. All the personnel, realizing what this meant, went down the factory at high speed in varying directions. A few of them took refuge in nearby large steam turbine exhaust casings, which made useful shelters.”
It had worked, but would take many months of re-engineering before he was confident enough to promote the engine. By April 1938, it ran for an hour at 8,200 rpm.
An improved version of the unit was demonstrated to the Air Ministry at 16,000 rpm in June 1939, and Power Jets received a contract for a jet engine for use in an experimental Gloster designed around it.
The bureaucracy of the Third Reich had worked more quickly. The world’s first jet airplane—a Heinkel He-178—made its first flight in August 1939.
However, five days later, Germany invaded Poland with ground forces and 1,600 aircraft. World War II had begun, and Hitler felt that with such decisive aerial might, he didn’t need another airplane whose effectiveness was unproved.
But when news of the German jet reached Britain, the Air Ministry took a sudden renewed interest in Whittle’s invention. Production of the prototype was sped up, and the first British jet flew May 15, 1941 equipped with a Whittle powerplant generating 840 pounds of thrust.
Rover was given a contract to build production engines but apparently didn’t comprehend the extent of the precision required, and after two years had not produced a satisfactory example, so the business was switched to Rolls-Royce, whose engines powered the first British operational jets beginning in March 1943.
Germany might well have gained air superiority had the order been given earlier, but the debut of its first production jet—the Me-262—had been delayed nearly six years. As a fighter, the 262 was nearly 100 mph faster than any Allied aircraft, but because Hitler had insisted the aircraft be outfitted as a bomber, it was heavy and its performance was disappointing.
Operational by late in 1944, more than 1,400 262s would be built before the end of the war; barely a third of that number ever saw combat. Ideologies aside, both Whittle and Ohain had succeeded despite the protestations and meddlings of their benefactors.
The Jet Age
Whittle had furnished an experimental jet engine to the U.S. government, who turned it over to General Electric for development. In 1942, a Bell P-59 Airacomet became the first American jet to fly.
In the postwar years, the jet-powered fleet of the military grew by leaps and bounds. In 1948, Vickers designed and built the first turboprop airliner, the Viscount, and in 1952 the first turbojet airliner—the deHavilland Comet—began flying regular routes. The perception was that it was all about speed and performance.
When Boeing took the wraps off its 707 in 1957 and airlines entered the Jet Age, they figured out that the gas turbine was more about efficiency and operational economy than quickness. Instead of counting downtime for regular rebuilds and the constant adjustments demanded by big radials, turbine operators were more likely to be counting productive flying hours and the money they were saving.
General Aviation began using dedicated turbine-powered transports in the mid-1950s with the Grumman Gulfstream, Sabreliner and Lockheed JetStar. By the 1960s, Jet Commander, LearJet, and Beech had joined the ranks, and over the next decade Piper and a dozen more manufacturers were buying their powerplants from Allison, Pratt & Whitney, Garrett, Williams and GE.
In 1980, (Sir) Frank Whittle and Hans von Ohain jointly received the NBAA Award for Meritorious Service to Aviation.
Daryl Murphy began his writing career in the 1950s and learned to fly in the 1960s. Of late, his articles have gravitated toward aviation history, because, as Piper Flyer publisher Jennifer Dellenbusch reasoned, “You were there when it happened.” Send questions or comments to editor@www.piperflyer.com.
