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by Dr. Marshall Michel
86th Airlift Wing Historian
***image1***By the early 1950’s, the Cold War was in full swing and both the U.S. and Soviet Union were striving for a long-range jet bomber force to deliver nuclear weapons. The U.S. had the first effective strategic jet bomber, the B-47, and in 1951 the Strategic Air Command commander, Gen. Curtis LeMay, drove the Air Force to order a very long range all jet bomber from Boeing, the seemingly immortal B-52.
In the race to develop a long-range jet bomber, the Soviet Union lagged far behind. The Soviet Air Force was mainly focused on tactical aircraft. In World War II, they virtually did not have any long-range bombers in the class of the B-17, much less the B-29, nor did their aviation industry have the capability to build them. When the Soviets developed an atomic bomb and needed a delivery platform, they simply copied rivet by rivet, B-29s that had landed in Soviet territory after being damaged in missions over Japan. While this Soviet version of the B-29, the Tupelov Tu-4 “Bull,” served as an acceptable stopgap, it was soon obsolete. In 1949, Stalin ordered the development of a strategic jet bomber. The first prototype of a strategic jet bomber, the elegant four-engine Myasishchyev Mi-4 Molot (Hammer) flew in 1953, about a year after the B-52’s first flight. While the Mi-4 caused a considerable stir when it was first publicly displayed, it fell far short of the range required to make it an effective strategic bomber.
Fortunately for the Soviets, Tupelov had worked on massively improving the B-29. He had first tried making it larger but by 1950 he was working on an entirely new design. The new design was a swept wing, long-range bomber with roughly the same capability as the B-52 but propeller driven.
While achieving high performance with propellers seems to be ludicrous, when the jet engine was first developed there were attempts to solve its main problem, short range, by using the turbine to turn a propeller for propulsion. The engine was known as the turboprop.
The turboprop offered a number of advantages but it was considered unsuited for high performance aircraft. If it had to drive a propeller, and the propeller tips produced steadily more drag as it approached the speed of sound, this drag offset any increase in horsepower. There seemed to be a finite limit to propeller driven aircraft performance.
As the U.S. developed steadily more efficient jet engines, the turboprop was related to uses where efficiency was the main issue. For Tupelov, a large turboprop seemed to offer the only chance for high performance on a bomber. The engine itself would have to be huge, capable of producing 12,000 horsepower and by 1952 such an engine was built, the NV-12. The major problem was developing propellers that could use the power of the NV-12.
After a lot of testing the engine group settled on two contra-rotating propellers per nacelle. The propeller’s tip was carefully designed to make it capable of supersonic speed, Mach 1.08, something that had been considered impossible by Western designers. That allowed the engine to perform at maximum efficiency. Combined with a slim fuselage and swept flying surfaces Tupelov’s design, the Tu-95 (named “Bear” by NATO) was roughly the same size as the B-52, had a top speed of about 530 knots and a range of about 11,000 miles. Interestingly, at cruise speed the design of the propellers makes them seem to be hardly moving (see picture above), graphically illustrating their efficiency.
But while the B-52 and Tu-95 are similar in size and both are still in service, they perform entirely different missions. The B-52 has proved remarkably adaptable, moving from a high level nuclear bomber to a low level nuclear bomber to an extremely effective conventional bomber. The Bear has been produced in a bewildering number of variants and is mainly used for long-range reconnaissance missions. In wartime, it was expected to locate U.S. Navy carrier formations far out to sea and to attack them with air to surface missiles. E-mail questions and comments to marshall.michel@ramstein.af.mil.
