Kalinin K-7 is one of the main Russian metal monster planes built in the 1930s. It is an artificial flying machine of brilliant inventiveness. Kalinin K-7 was a heavy experimental Russian aircraft that featured an unusual configuration with double arrows and large pods under the wings housing fixed-wing craft and machine gun turrets mounted inside pods, designed in the early years. 1930.
With a capacity of 120 passengers, it was powered by 7 Mikulin AM-34F V-12 piston engines. It could fly at a speed of 140 miles per hour and be armed to the teeth with 8 20mm and 8 mg cannons in its gunship variant. This largest flying fortress is a true engineering marvel for its time.
Built as a multi-mission aircraft, the Kalinin K-7 was to serve both military and civilian purposes. The powerful K-7 military aircraft could carry over 16 tons of bombs, equipped with 12 firing stations and a unique electronic vehicle that transported shooters to bombers in the tail of the aircraft. It is a very impressive flying machine, but a complete failure as it exceeded its own cargo weight and only made six flights before crashing due to a tail boom failure, killing 14 people. . The strange Russian Kalinin K-7 never made it beyond the experimental stage, but it did help advance the potentials of aviation technology and wrote a history in Russian aviation to spread the idea of multi-aircraft. -missions to the next era.
Specific introduction to Kalinin K-7
Kalinin K-7 is a human madness machine dating from the aviation era of the 1930s. It made its first flight on August 11, 1933. The super heavy Kalinin K-7 is even bigger than the B- bomber. 52 today because it has a wing area of 454 km². Even with this monstrosity, he could take off. It was fitted with a chromium-molybdenum steel airframe and had six tractor engines on the leading edge of the wing. An engine was installed in the pusher configuration at the rear of the rear fuselage. Initially it had seven engines which later became a total of 8 engines on the main wing due to exceeding the maximum weight. The Soviet Union manufactured the K-7 in two years in Kharkiv, Ukraine, starting in 1931.
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Kharkiv Aviation Factory owns unusual aircraft and has a glorious history of over 90 years, which began in 1926.
Kalinin K-7 had an unusual construction that involved heavy bombing or civilian transport missions. The aircraft was designed to carry 120 civilians and 11 crew members, and 7 tonnes of mail on civilian transport missions.
During a combat helicopter / bomber mission, the K-7 was configured to accommodate 11 crew members and people to handle the machine guns, carrying 8 × 20mm, 8 × 7.62mm cannons, 9.6 tons of bombs and other weapons for the carrier paratroopers. The aircraft could carry 112 paratroopers equipped with fuel and 11 crew members as a personnel carrier.
Strange Kalinin K-7
Kalinin K-7 was an eye-catching aircraft unlike today’s common and boring aircraft which has similar standard designs. The one-of-a-kind Kalinin K-7 looks more like a tank with a wingspan of over 170 feet, which is a cult icon for weird and weird aircraft fanatics. The experimental Kalinin K-7 was unable to dominate the Russian skies due to several issues. The K-7’s 53 m long wingspan is more than double the size of the Martin B-10 which measured 21.5 m.
The length of the K-7 was 28 m and was 12.4 m high with a service ceiling of 400 meters. The aircraft’s empty weight was 24,400 kg and its maximum take-off weight was 46,500 kg. It could store 9130l of fuel in its wing tank and had two-bladed fixed-pitch propellers.
This Soviet aircraft installed a flying wing design with twin arrows rather than using a fuselage. The massive wing housed a huge landing gear as well as multi-engine and was so large inside that it could accommodate enough rooms, including sleeping quarters, cabins, a radio room, a smoking room, and a small restaurant. . The heavy bomber was designed by Konstantin Kalinin, who was a Soviet WWI aviator and aviation enthusiast. Soviet veteran Kalinin was also the designer of successful K-4s and K-5s, used for photographic surveys and as a reconnaissance airliner. These were small planes that could accommodate 10 to 12 passengers. The K-5 quickly became the most produced Russian aircraft with 260 numbers built.
The K-7, on the other hand, was designed to serve some of the most remote places in the Union of the Soviet Socialist Republic (USSR) that were not accessible to small planes due to refueling issues. Aimed at long-range military heavy bombers and heavy transport aircraft, it was the crème de la crème of air travel when it began its first flight, but the design remained only an experimental prototype since it was canceled in 1935.
Kalinin K-7 unsuccessful pioneer flight
The inaugural flight of the Kalinin K-7 was not a success as it showed severe instability. The cell resonating with the frequency of the motor created a serious vibration. At that time, no extensive research had been done regarding the natural frequencies of structures and their responses to vibrations. Thus, the experts of the time shortened and reinforced the tail boom to solve the problem of instability. The huge propeller continued to create a lot of vibration. Seven test flights were made with the Kalinin K-7 before the aircraft crashed on November 21, 1933 when the tail boom suffered a structural failure causing the elevator to jam. In aeronautics, an elevator is a flight control surface used to control the position of the nose of the aircraft by changing the shape of the wing of the horizontal stabilizer.
Unique sole design and character of the Kalinin K-7
Kalinin’s awe-inspiring design in the K-7 mammoth was the innovative aspect of an aircraft when reliance on alien technology was minimal and viewed as vulnerable. The materials used in making this giant creation were lightweight chrome-molybdenum steel instead of aluminum or even fabric covered wood. Unique and local materials from the interior of the USSR have an excellent strength-to-weight ratio. Soviet-designed pieces were the unique aspect of this flying fortress that was to kick off a Soviet aerospace industry. Structurally, twin arrows made up the rear part of the fuselage with a wide-span wing set rounded off at the wing tips. The aircraft cockpit and main crew area had thick framing to ensure good visibility. The welded steel provided the required tolerances while the struts connected the gear equipment and fairings to the structure of the aircraft itself.
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The political importance of K-7
Instead of importing steel, the Soviet Union made full use of domestic steel, which represented the victory of the highest political importance.
The eventual fate of Kalinin K-7
The versatile Kalinin K-7 is an ambitious and brash creation of the USSR, which was the largest aircraft to take off on a propeller engine in its short career. The eventual fate of Kalinin K-7 was devastating and similar to that of its chief designer Kalinin who was arrested and executed during the high-level Stalin purges or the Great Terror of the late 1930s when he was accused of espionage and anti-Soviet activity.
The latest of a handful of test flights during Kalinin K-7’s short altitude tenure resulted in the departure of the K-7 from the USSR when it killed 14 people on board and one on the ground. All of Russia’s efforts on K-7 production or political intrigue created widespread speculation around the plane crash regarding the potential for sabotage which could not come to a proper conclusion. Although two additional prototypes were planned to serve the dual function of troop and civilian airliner in a propaganda victory for the Soviet Union, they were never completed as the project was canceled in 1935. Only four years after the manufacture of a single Soviet bomber, the project was quickly abandoned by the USSR.
K-7 is a complete failure in terms of commercial exploitation. But it demonstrated the innovative and technological aspects of the USSR, which uses national designs of steel and airplanes, which was a revolutionary change pushing aside foreign technology. Although the K-7’s ultimate failure to participate in the flourishing Soviet aircraft industry destined it to be only an experimental aircraft, it has one of the most striking designs with a double boom fuselage and nacelles under the remarkable wings and remains a charming feat.
The aircraft of its kind Kalinin K-7 is pretty cool in terms of size. However, aesthetics and charm do not always guarantee the commercial success of majestic aircraft. The larger propeller plane, the K-7, is a good example. Once a cutting edge quirk, K-7 was arguably ahead of its time without the help of advanced computer technology and sophisticated wind tunnels.
About the Russian aviation industry
Russia is a large country specializing in the production and manufacture of airplanes. With a long history of nearly a century for Russian civil aviation, it largely won the supersonic passenger jet race of the first DOBROLET civilian airliner. Airlines such as Aeroflot, Babyflots, Rossiya, Pobeda, S7 Siberian and United Aircraft Corporation are the main players in the Russian aviation industry. The Irkut MC-21 program with a Russian-built engine option aims to end the long-term dominance of the Airbus A320 and Boeing 737.