Bereznyak-Isayev BI-1

https://en.wikipedia.org/wiki/Bereznyak-Isayev_BI-1

The Bereznyak-Isayev BI-1 was a Soviet rocket-powered fighter developed during
the Second World War.

On 21 June Isaev proposed a new design using compressed air instead of a pump to
force propellant to the engine. The next day, Operation Barbarossa brought the
Soviet Union into World War II, and the rocket-powered interceptor suddenly
became important. Bereznyak and Isaev began a new more detailed design, which
they finished in three weeks. On 9 July Bolkhovitinov and his project-G team met
with Andrey Kostikov the head of RNII. Dushkin was not happy about the idea of
bypassing his fuel pump design, but they backed the plan and cosigned a letter
that was eventually shown to Joseph Stalin. After giving a report at the
Kremlin, they were ordered to build the aircraft and were given only 35 days to
do so. The official order was dated August 1, but work began in late July. The
engineers were given leave to visit their families, and then literally lived at
the factory until the aircraft were finished.

The new design was called "BI" for Blizhnii Istrebitel (close-range fighter),
but the letters were also understood by everyone to stand for its inventors:
Bereznyak and Isaev. The original plan to include four machine guns was replaced
by a design with a pair of 20 mm (0.79 in) ShVAK cannon. The new aircraft was a
low-wing monoplane 6.4 m (21 ft) long, with a wingspan of 6.5 m (21 ft) and an
estimated take-off mass of 1,650 kg (3,640 lb) (including 710 kg (1,570 lb) of
propellant). Working around the clock, local furniture workers were employed to
build the first two prototypes (BI-1 and BI-2). The skin was 2 mm (0.08 in)
plywood with a bonded covering of fabric. The ailerons, elevators and rudder
were fabric covered, and the flaps were duralumin. In the forward section were 5
compressed air tanks and 2 kerosene tanks. In the aft were 5 compressed air
tanks and three nitric acid tanks. Pressurized to 60 bar (6,000 kPa), the tanks
were made from a high-strength chromium-manganese-silicon steel ("Chromansil")
that was not especially resistant to corrosion. Thus, the acid tanks had to be
replaced periodically. Compressed air was also used to retract and deploy the
landing gear and to power the built-in cannon.


Role
Fighter

Manufacturer
OKB-293

Designer
A.Y.Bereznyak and A.M.Isayev

First flight
15 May 1942

Retired
9 March 1945

Primary user
Soviet Air Force

Number built
9

The 21 March flight was with a full load of ammunition, however most of the BIs
did not carry weapons, and although some reports claim that BI-4 was used for
live ammunition tests, the guns were never fired in flight. The BI-4 model was
also reportedly to be used as the template for mass production of 30 to 50 BI-VS
aircraft by Andrey Moskalev's factory, with Moskalev augmenting the twin ShVAK
cannon with a load of ten thermite bombs.

On 27 March, during a low-altitude test flight, BI-1, piloted by Backchivandzhi,
enterred a 45-degree dive and crashed into the ground, killing Backchivandzhi.
The accident put a halt to flight tests, and a lengthy investigation began.
Eventually, after wind tunnel testing, it was determined that BI-1 lost control
due to transonic effects on the pitch controls / stabilisers. Estimates of
Backchivandzhi's final velocity range from 800 to 900 km/h (430 to 490 kn; 500
to 560 mph), but the recording instruments were too damaged by the crash for a
reliable measurement. The 27 March is considered a black day in Soviet aviation
history, also being the date that Yuri Gagarin died in a MiG-15UTI crash. In
1973, Backchivadzhi was posthumously elevated to Hero of the Soviet Union.

As turbojet aircraft began to appear in the mid 1940s, the lack of prospects for
further development of rocket aircraft in general, and BI in particular,
primarily due to limited flight time became evident.

However, the experience accumulated by Bolkhovitinov design bureau became
invaluable, and the design bureau alumni went on to become prominent figures in
soviet rocket and space technology. Two BI engineers became the founders of two
design schools: Bereznyak founded OKB-155, which was the USSR's leading design
bureau in development of cruise missiles, and Isayev became the founder of
OKB-2, which specialized in low and medium thrust liquid-propellant rocket
engines for rockets and space vehicles.

Specifications

General characteristics
Crew: 1
Length: 6.40 m (21 ft 0 in)
Wingspan: 6.48 m (21 ft 3 in)
Height: 2.06 m (6 ft 9 in)
Wing area: 7 m2 (75 sq ft)
Empty weight: 958 kg (2,112 lb)
Max takeoff weight: 1,683 kg (3,710 lb)
Powerplant: 1 × Dushkin D-1A-1100 liquid-fuel rocket motor, 10.79 kN (2,430 lbf)
thrust

Performance
Maximum speed: 800 km/h (497 mph; 432 kn) estimated
Endurance: 15 minutes under power

Armament

Guns: two nose-mounted 20 mm Sh VAK cannon




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"Miloch" wrote in message news

https://en.wikipedia.org/wiki/Bereznyak-Isayev_BI-1

The Bereznyak-Isayev BI-1 was a Soviet rocket-powered fighter developed
during the Second World War.

I understand a surviving pilot described flying it as "riding a tiger."