The SPB high-speed dive bomber was designed on the basis of the VIT-2. SPB. The need of the Air Force for such an aircraft was very great, therefore, to speed up testing and development at the Moscow plant No. 22, in addition to two prototypes, built a small series of three aircraft.

Compared to VIT-2, the following changes have been made to the design:

1) retractable radiators in the wing were abolished; instead of them, tunnel radiators were installed behind the engine nacelles; the suction pipes were transferred to the wing nose;

2) instead of a ShVAK cannon, a BT machine gun was installed in the gunner's cockpit;

3) two connectors were introduced into the fuselage;

4) the rear of the cockpit and fuselage was changed;

5) a hatch installation with a ShKAS machine gun was introduced;

6) instead of the ShVAK cannon, a ShKAS machine gun was placed in the bow rifle mount.

For the convenience of shooting from the rear rifle installation, part of the gargrot behind the glazing was folded using a special mechanism.

Ground tests of the first prototype of SPB No. 1-0 began on January 3, 1940. Flight tests were delayed due to untimely completion of static tests and the flight of SPB No. 1-0 took place only on February 18, 1940, B. N. Kudrin. On March 26, 1940, MA Lipkin made the first flight on the second prototype of the prototype aircraft (No. 2-0).

The assembly and adjustment of SPB No. 1-0 was carried out with deviations from those. conditions, which could not but affect the behavior of the machine in the air. BN Kudrin noted that SPB No. 1 -0 pulled into a dive at speeds over 400 km/km on the instrument with a sharp increase in efforts to pull out of the dive. Because of this, Kudrin could not even for a short time remove his hand from the control wheel to turn on the elevator trim. After a repetition of a similar incident, he refused to fly by plane.

This aircraft was flown by M.A. Lipkin, with the same result. The director of the plant No. 22 ordered to prohibit the tests of SPB No. 1-0 until the deviations in the regulation are eliminated.

SPB # 2-0 has been adjusted better. However, his trials did not last long. On April 7, 1940, the aircraft suffered an accident: during the landing run, both landing gear struts broke because of a manufacturing defect.

On April 26, the second serial SPB No. 2-1 was brought out for testing. After flying over the factory airfield, test pilot P.G. Golovin overtook him to the Central airfield, noting that the water and oil temperature of the right engine was 15 degrees higher than the left one. The next day, Golovin again lifted the aircraft into the air. The task involved determining the stability and controllability of the SPB at an altitude of 2000-3000 m in the area of ​​the Central airfield. The takeoff was watched by Polikarpov, Zhemchuzhin, the head of the technical bureau of the Usachenko plant, soon the plane disappeared into the cloudy sky. Half an hour later, at 7:15 pm, the SPB in the area of ​​the NII GVF airfield in Tushino "fell out" of the clouds, fell into a tailspin near the ground, fell and caught fire, burying the crew under the rubble.

In December 1940, tests of the pre-production PB-100 began, and at the beginning of 1940, the first serial Pe-2s began to leave the assembly shops of factories No. 22 and No. 39. This aircraft slightly surpassed the SPB in maximum speed at design altitude, but was inferior to it in climb rate and could carry fewer bombs on its internal sling.

This is how the history of St. Petersburg ended. One of the built aircraft was transferred to the Moscow Aviation Institute and used to train students.

Stopping the construction of St. Petersburg, the management did not take into account the time factor. The war was rapidly approaching our borders. The introduction of the Pe-2 into the series was slow. It was required to make tooling, debug production. Before the start of the war, only 64 aircraft were delivered to the Air Force. They had to be mastered in battles, suffering significant losses. As a result, the Air Force switched to dive bombing only in 1943.

Photo	Description
	Drawing SPB

Bibliography

• "The history of designs of planes in USSR 1938-1950" /Vadim Shavrov/
• "The planes of Stalin falcons" /Konstantin Kosminkov and Dmitriy Grinyuk/
• "Fighter I-16" /Mikhail Maslov/
• "The Soviet planes" /Alexander Yakovlev/