On July 12, 1940, Viktor Fedorovich Bolkhovitinov attended a special commissar meeting calling for the development of a high-speed stratospheric aircraft with his top two engineers, Aleksander Bereznyak and Aleksei Isayev. Barely over a year later, on 1 September 1941, the Bereznyak-Isayev (BI) 1 was completed and ready for gliding tests, as the planned engine was still not ready. By the next year, the full aircraft was ready for its primary tests, and on 15 May 1942, test pilot Grigory Yakovlevich Bakhchivandzhi piloted the BI-1 during its first powered flight. Due to the highly toxic and corrosive fuel mixture used by the BI, utilizing a mix of tractor kerosene and red-fuming nitric acid, the BI-1 became too corroded by acid to fly safely shortly after, and was retired. The second prototype (BI-2) was built and Backchivadzhi made the second flight on 10 Jan 1943. The BI program would progress steadily over the next few years, showing great promise for a point defence/short range interceptor. However, the dangers of the program, mainly the lack of reusability and feasibility due to the short lifespan of the airframes and their very expensive and dangerous fuel mixture, resulted in a growing sentiment against the BI from the higher ups. Unfortunately, on 27 March, during a low-altitude test flight, the BI piloted by Bakhchivandzhi entered a 45-degree dive and crashed into the ground, killing Bakhchivandzhi. Whilst unknown at the time, the conventional wing design resulted in severe control "compression" when nearing transsonic speeds. By late 1944, it was very obvious at the BI program had reached a stalemate, and any further development was overshadowed by the advent of turbojet aircraft, performing the same role for a fraction of the price, preparation, and risk. However, it is not to say that the BI program was fruitless, as the knowledge obtained by Bolkhovitinov design bureau about rocket science became pivotal in future Soviet rocket and missile developments.

The BI, introduced during Update "Raining Fire" as a reward for the 2020 Wargame "Strategist" event, is a very rare and peculiar aircraft. The BI is very strong for its battle rating as a result of its peculiar characteristics: The aircraft has less than two minutes of fuel and a comically small ammunition pool. However, the aircraft still retains all the advantages of a rocket powered plane, being its instantaneous acceleration, absurd thrust, and insanely good fuel efficiency at high altitudes with proper throttle management. This results in the BI being a very high skill level plane, which when played right, can be almost unbeatable by all that it faces; be it the late superprops or the early jets of its battle rating. Due to its rarity, most players have never faced one, and fail understand its weaknesses to defeat it. The BI, due to utilizing a very lightweight airframe with conventional wing and tail designs, suffers from horrific control surface compression and lift degradation above 600 km/h, and enters an almost complete loss of control nearing 700 km/h or higher. This, in turn, means that the BI's greatest weakness is diving.

As such, the ultimate tactic to use against a BI is to build up speed, especially by diving away if necessary. Less experienced BI pilots will either meet their doom by following you, or completely throw their altitude advantage away trying to recover the aircraft from the dive. More experienced BI pilots will simply disengage, letting you live rather than risk the dive. One must always keep in mind that the BI has a thrust-to-weight ratio of up to 0.99 at optimal conditions, the highest by far in its entire BR range, meaning the BI in the hands of competent pilots will always win engagements which are based on energy or thrust.