The Soviets built some of the largest and most technically advanced helicopters in the world. By 1957, the Mil Mi-6 had already emerged as the largest helicopter ever built, far out-sizing helicopters built in the west. But for the Soviet Union, the need to build a helicopter far larger than even the Mi-6, soon became a matter of national security.
By 1960, American U-2 spy planes conducting high altitude reconnaissance flights over the Soviet Union were beginning to uncover the location of the country’s Intercontinental Ballistic Missile (ICBM) sites. These first generation R-7 Semyorka ICBMs were being deployed throughout the Soviet Union as fast as possible, but their enormous size and weight meant they could only be delivered to launch sites using trains. The need to build rail lines to launch sites made the ICBM sites easy to spot in U.S. reconnaissance photos.
Keeping the missile sites hidden was a matter of national security. The Soviets devised a bold plan to airlift ICBMs into the vast and remote Soviet wilderness, thereby eliminating the need for rail lines or even roads. This would make it virtually impossible for spy planes to track down missile sites hidden in over twelve million square kilometres of forests. But to make the plan work, the Soviets would need to build a helicopter with at least twice the lifting power of the Mi-6.
Design studies for the new enormous helicopter began in 1959, with the Soviet Council of Ministers formally approving development in 1962. But development of such an ambitious helicopter would progress slowly, as various configurations (single rotor, tandem and transverse) were studied. Construction of testing-rigs, transmission systems and mock-ups began in 1963, and construction of the first prototype started in 1965. The new prototype would be designated as the Mil V-12 (with plans to designate the production version as Mil Mi-12). The first test flight in 1967 ended in failure as the V-12 crashed back to earth sustaining minor damage due to oscillations caused by control problems. A second test flight a year later proved the helicopter’s airworthiness.
The V-12 would go on to break numerous world records for lifting capacity, but it’s fate had already been sealed by a rapidly changing strategic situation. The introduction of spy satellites, and the development of new lighter and mobile ICBMs made hiding nuclear missiles strategically irrelevant.
In 1970, the Soviet Air Force refused to accept the V-12 into state acceptance trials, due to a lack of need. Although a second V-12 prototype would be constructed in 1972, there were simply too few scenarios that would require such a large and complex helicopter. In 1974 development of the V-12 was cancelled and the Mil Design Bureau shifted efforts to designing the Mil Mi-26, the largest helicopter to enter service.
UAV DACH: Beitrag im Original auf https://www.uasvision.com/2020/09/18/the-largest-helicopter-ever-built-the-mil-v-12-story/, mit freundlicher Genehmigung von UAS Vision automatisch importiert. Der Beitrag gibt nicht unbedingt die Meinung oder Position des UAV DACH e.V. wieder. Das Original ist in englischer Sprache. Für die Inhalte ist der UAV DACH e.V. nicht verantwortlich.