Operation of a turbojet engine Main article: Also called a turbojet. The gases generated by the gas turbine, to be expelled, providing the bulk of engine thrust. It was the first form of turbojet system and was invented by Frank Whittle, who conceptualized this innovative form of propulsion in the late thirties. By being repeatedly rejected by the British Air Ministry as it would violate the Treaty of Versailles aeronautical developments that prevented war or military purposes, Whittle published his theories in various scientific journals, while in 1935 the company founded Power Jets which is committed to operating their new engine. Ironically, the German engineer Hans von Ohain inspired Whittle’s publications, is the first to succeed in building a jet engine for a manned mission under the patronage of Dr.Ernst Heinkel, however like Whittle, the project was rejected by the Luftwaffe for different reasons despite having three different prototypes fully tested (I-178, I-280 and I-162 Salamander), and the company Messerschmitt was awarded the authorization to construct a fighter powered by a jet engine, the famous Messerschmitt Me-262, the first airplane pilot and production not to be propelled by turbines. It would create the most advanced jet engine of World War II, the He S 011. After the Second World War, the Rolls-Royce company leading the development of turbojet engines in the mid-forties, and later General Electric and Westinghouse companies were used to produce variants of these engines in the U.S..Pratt Whitney was the first U.S. company to produce a completely new engine with U.S. development, the Pratt Whitney J-57, awarded the Collier Trophy Award as the “greatest achievements of North American Aviation. The turbojet was the first jet engines used in commercial and military aviation. Had a greater unprecedented power that allowed the development of larger aircraft to fly at higher altitudes and high speed. Thanks to its notion of turbojet powered engines are popularly known as “jet engines”. Its long, narrow shape like a barrel or cigar, allowing more aerodynamic profile and more efficient aircraft designs. Unlike a reciprocating engine, its power is not measured in horsepower produced but in pounds of thrust, and the ability to produce thrust is affected by much higher altitudes than piston engines because of the high internal speed of operation and compressing the air that drive.The vast majority of the first types of turbojet produces centrifugal momentum, because the air compression is done by centrifuging the air circulating inside the engine. Today they are obsolete because of its high sound and low fuel efficiency and are only found in vintage aircraft and military.