Messerschmitt lamented: "Yes, the development of a large bomber is the dream of many aircraft manufacturers, but there are many failures in it!" Fortunately, with the support of our sufficient funds and strong technical strength, we can develop such a complex high-performance large bomber as the flying wing bomber. ”

Xiao Weiguo knew that what Messerschmidt said was also true, that in the early thirties, various major powers were developing their own large bombers or large transport planes, and it seemed that everyone was engaged in an aviation design and manufacturing competition to see who was bigger and who could fly farther.

In the USSR alone, there were several aviation manufacturing enterprises that designed several large aircraft, even giant ones. At that time, in the process of promoting industrialization in the twenties and thirties, the aviation industry, which had a weak talent and technical base, had already set off an upsurge in the pursuit of large aircraft.

Although Sikorsky, who had built heavy bombers before World War I, had moved to the United States, it also gave rise to other designers, Konstantin Kalinin. He was a pilot during World War I, and later founded the Aviation Academy and Aircraft Design Bureau in Kharkiv, which is the origin of many aircraft design and manufacturing enterprises. After developing several small and medium-sized civil aircraft, in 1929 Kalinin launched an attack on large aircraft, and he wanted to build an aircraft capable of carrying 120 people.

The most important feature of the aircraft designed by Kalinin is the elliptical wing, with a particularly large wing area, and this K7 large aircraft used to challenge the limits is no exception, it is a monoplane, the wingspan is larger than that of the later B29 bomber, and the thickness of the wing reaches 2.3 meters, what a huge challenge? Why design such a thick wing? In fact, Kalinin's idea was to set up a passenger cockpit in the wing, which is similar to that of a flying wing transport aircraft.

But. With such an aircraft, the drag is not as small as that of a flyplane, but very large. To prop up such a thick wing, Kalinen used a double tail brace layout and a large underwing fixed landing gear. Due to the unusually heavy body caused by the use of a large number of metal materials, it could not be allowed to fly only by the six Mikulin traction engines lined up on the leading edge of the wings, so a propulsion power of the same type was added to the rear of the fuselage. This engine has a single power of 550 kilowatts, and the total power of the whole engine is 3800 kilowatts, which is more powerful than the ghost bomber with 2 wind and thunder turboprop engines. However, it is almost twice as large as the Ghost Winger Bomber, as well as in weight.

Before the construction of the K7 began in 1931, the Soviet government demanded that priority be changed to a bomber, and the maximum bomb load was required to reach 19 tons, for which the aircraft had to be significantly modified. A self-defense turret was added to the nose and left and right tail supports. The landing gear fairing was enlarged to make a long strip of weapons pods, which could be equipped with machine guns and bombs, as well as ladders leading to the wings for personnel to enter and exit. When the first K7 was completed two years later, it looked like a pair of oversized roller skates.

This extra-large aircraft has been in test flights since August 1933, and is larger than the M40 transport aircraft of the Dragon Soul Ordnance Complex. What started as a short take-off and landing test, but the inefficiency of the power system and the instability of the flight state of this large aircraft were exposed, and the engines worked to cause severe resonances in the fuselage. Kalinin did not seriously look for the cause, but added steel plate welding reinforcement. Instead of solving the problem, this increased the weight of the body by another 10 percent, and the result was a cup. One day three months later, the right tail brace of the large plane broke, and the plane slapped directly to the ground from a height of more than 100 meters, killing 15 people.

The accident of this crash. It also made the K7 aircraft stillborn, and there were originally models similar to the M30 executive plane, as well as transport models, which could not be continued, and even Kalinin was executed because of this. Although the take-off weight of such a large aircraft reached 42 tons. The wingspan reaches 53 meters, but the maximum speed is only 230 kilometers per hour, and the ceiling is only a pitiful 4,200 meters.

At the same time, Tupolev, a famous aircraft designer, was also designing a bomber about the size of the K7. Known as the father of Russian aviation, Tupolev designed a series of famous bombers, such as the Tu-16, Tu-95, Tu-22 and Tu-160, which reached the world's top level. After the establishment of the Tupolev Design Bureau in 1922, Tupolev developed a variety of bombers for the Soviet Air Force. In 1933, he began to design the Ante 16 prototype, with the goal of carrying 10 tons of bombs, for which the large bomber was equipped with four Mikulin aviation piston engines on the leading edge of the wings like the K7, and a pair of pull-back engine combinations on the back, six engines, only one less than the K7. However, after the test flight, it turned out that such a layout was very unsuccessful, so it was quickly abandoned.

Tupolev then took out the Ante 20, a monoplane with an all-metal fuselage, with a total of eight 550 kW Mikulin piston engines, two of which were mounted in tandem above the fuselage, like the Ante 16. With a wingspan of 63 meters, a total length of 33 meters and a maximum take-off weight of 53 tons, this aircraft can be said to have surpassed the later B52 strategic bombers in wingspan. Its name was named after the famous writer Gorky, although the flight performance of the Gorky was average, but its huge fuselage, which appeared full of aura, became a symbol of Soviet aviation achievements.

However, this aircraft was also short-lived, and in the end it was not mass-produced. Because during a flight demonstration in 1935, a fighter pilot who was flying at close range performed a stunt on a whim and did not want to lose control and crashed into the Ante 20, causing both planes to crash and 45 people to die. There was also a modified Ante 20 that flew as a passenger aircraft for several years and crashed due to improper operation.

It can be said that it is not easy for large aircraft, especially large bombers, to achieve real success and enter mass production. Without sufficient technical accumulation and insufficient financial support, it is impossible to complete. However, the Dragon Soul Ordnance Consortium is definitely the strongest aviation manufacturing enterprise now. The success of the test flight of the M40 large transport aircraft, as well as the success of the Wind and Thunder series engines, made the Ghost flying wing bomber feasible, and of course, the most important thing is that Xiao Weiguo, a traverser, a future military expert, has mastered many technologies that are not available in this era. (To be continued.) )