During the height of the Cold War, Russian engineer Rostislav Evgenievich Alexeiev conceived what would become known as “ekranoplanos” – vehicles halfway between a ship and an airplane. At more than a hundred meters long and powered by ten engines, it flew just three meters above the water's surface, cutting through waves as high as five meters without trouble. An accident in 1980 put an end to this initially secret Soviet development, which American spies had nicknamed “The Monster of the Caspian Sea”.
The Cold War was the backdrop for the development of the strangest technologies. Battle tanks the size of battleships, or cannons that required thousands of men to operate. Aviation also saw some truly astonishing experiments. One of them was the series of Russian aircraft-ships known as “ekranoplanos”.
A Discovery from Space
Everything began in the 1960s, when American spy satellites photographed the coast of the Caspian Sea. Analysts determined that the strange shapes in the images—despite their size—could only be an airplane.
Over 100 meters long with almost square wings, this machine was something completely different from anything known. U.S. intelligence agencies soon nicknamed it “The Monster of the Caspian Sea” and quickly began investigating its origin and characteristics. Several months later they discovered it was not exactly an airplane, but a kind of ship weighing 550,000 kilograms, yet capable of flying close to the water by exploiting what is sometimes called the “ground effect.” The Ekranoplan KM, as the Russians called it, could only fly at very low altitude, but far from being a limitation, this made it practically undetectable by radar.
Ground Effect and the KM's Design
Responsible for its design was engineer Rostislav Evgenievich Alexeiev, who had specialized in developing surfaces that could support great weight while “flying” almost at floor or water level. The Ekranoplan KM would become a new means of transport, taking the best of both airplanes and ships. Nikita Khrushchev became so interested in the project that he gave Alexeiev unlimited funds to carry out his research. What began as modest scale models, built from paper and launched down a slide, became—thanks to Soviet money—a real prototype. Powered by ten engines, eight in the front of the fuselage and two more at the tail (essential for the extra thrust needed during takeoff), the first ekranoplane flew for the first time in October 1966.
It could rise only about 30 centimeters above the water, and its designer claimed it could not fly more than 3 meters without running a serious risk of crashing. But that was not a serious problem, since waves up to five meters high could be “crossed” without difficulty by the enormous vehicle. The KM served for thousands of tests, and the Russians learned practically all the secrets of this technology. The adventure ended in 1980, when the Ekranoplan KM suffered an accident and never flew again. Apparently, a lateral gust of wind destabilized the aircraft. The pilot, ignoring the designer's advice to approach the water surface in case of trouble, followed his instincts and, as if piloting a traditional airplane, tried to gain altitude to avoid the crash. This caused the “ground effect” that kept the KM in the air to diminish, and it plunged into the sea.
What kept the Ekranoplan KM in the air was the lift that airplane wings experience when flying very close to the ground. This is due to an excess pressure on the air circulating between the wings and the surface. That pressure creates an “air cushion” and helps the aircraft stay in flight. To maximize this effect, ekranoplanes had square and “split” wings, so that the airflow naturally directed toward the lower part of the aircraft. But this effect diminishes as the aircraft rises, so the KM could not fly at high altitudes.
The A-90 Orlyonok and Later Designs
Before the KM accident, Russian engineers created more models, such as the A-90 Orlyonok (Little Eagle), weighing 140 tons and only 58 meters long, powered by two turbojet engines that allowed it to reach speeds of 400 km/h in 1972. This machine, with a range of 1,500 km flying between 5 and 10 meters high, was designed for assault missions. Construction of 120 units for the Soviet Navy was planned, but the nation's crisis meant only three or four were built, which remained in service until 1993.
Alexeiev designed other similar craft, larger or smaller, capable of carrying nuclear bombs, missiles, tanks, and trucks. But like the Spasatel (the savior), an ekranoplane with capacity for 500 people intended as a flying hospital for ship and submarine crews, they were canceled before being built due to lack of funds. The Monster of the Caspian Sea, one of the largest vehicles ever built, rests on the shore of the sea.
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