BI

BI

BI

USSR

V Rank

Battle rating:

AB	RB	SB
6.7	6.7	6.3

Class:

Fighter

Jet fighter

Purchase:Bundle or Gift

MARKET

Description

The BI is a gift rank V Soviet fighter with a battle rating of 6.7 (AB/RB) and 6.3 (SB). It was introduced during Update "Raining Fire" as a reward for the 2020 Wargame "Strategist" event, and is currently available for sale on the Marketplace.

Nicknamed the "Devil's Broomstick", the Bereznyak-Isayev BI was one of the world's first rocket-powered fighter aircraft. Envisaged as a short-range point interceptor, it features extremely high acceleration and climb rate, in return for extremely limited fuel.

General info

Flight performance

Max speed

at 2 000 m799 km/h

Turn time23 s

Max altitude12 000 m

EngineIsaev D-1a

TypeRocket

Cooling systemAir

Take-off weight2 t

Characteristics	Max Speed (km/h at 2,000 m)		Max altitude (metres)	Turn time (seconds)		Rate of climb (metres/second)		Take-off run (metres)
	AB	RB		AB	RB	AB	RB
Stock	791	786	12000	23.2	23.2	84.7	79.1	300
Upgraded	807	799		22.8	23.0	116.6	100.0

The BI taking off.

Details

Features
Combat flaps	Take-off flaps	Landing flaps	Air brakes	Arrestor gear	Drogue chute
X	X	✓	X	X	X

Limits
Wings (km/h)	Gear (km/h)	Flaps (km/h)			Max Static G
		Combat	Take-off	Landing	+	-
920	420	N/A	N/A	320	~9	~3

Optimal velocities (km/h)
Ailerons	Rudder	Elevators	Radiator
< 400	< 410	< 550	N/A

Engine performance

Engine			Aircraft mass
Engine name		Number	Basic Mass	Wing loading (full fuel)
Isaev D-1a		1	924 kg	233 kg/m2
Engine characteristics			Mass with fuel (no weapons load)		Max Takeoff Weight
Weight (each)	Type		0m fuel	1m fuel
300 kg	Liquid-fuel rocket		1,134 kg	1,629 kg	1,650 kg
Maximum engine thrust @ 0 m (RB / SB)			Thrust to weight ratio @ 0 m (100%)
Condition	100%	WEP	0m fuel	1m fuel	MTOW
Stationary	1,121 kgf	N/A	0.99	0.69	0.68
Optimal	1,121 kgf (any speed)	N/A	0.99	0.69	0.68

Survivability and armour

Crew1 person

Speed of destruction

Structural920 km/h

Gear420 km/h

• 5.5 mm steel behind the pilot.
• 5.5 mm steel plate installed in the nose.
• 64 mm bulletproof glass in front of pilot
• Self-sealing fuel tanks* (7 under the cannon barrels, 8 behind pilot, 3 in rear fuselage)

*The fuel tanks are cylinder-shaped, not rectangular, like most planes' fuel tanks, allowing for more fuel tanks.

Modifications and economy

Repair costBasic → Reference

AB4 012 → 4 890

RB9 654 → 11 768

SB14 235 → 17 352

Total cost of modifications80 000

129 000

Talisman cost2 000

Crew training78 000

Experts270 000

Aces1 500

Research Aces670 000

Reward for battleAB / RB / SB

130 / 280 / 560 %

190 / 190 / 190 %

Modifications

Flight performance	Survivability	Weaponry
Fuselage repair Research: 8 000 Cost: 13 000 220 Wings repair Research: 10 000 Cost: 16 000 270 Engine Research: 13 000 Cost: 21 000 350	Airframe Research: 18 000 Cost: 29 000 490 Cover Research: 13 000 Cost: 21 000 350	shvak_belt_pack Research: 8 000 Cost: 13 000 220 shvak_new_gun Research: 10 000 Cost: 16 000 270

Armaments

BI after using its two cannons to down a Ar 234.

Offensive armament

Weapon 12 x 20 mm ShVAK cannon

Ammunition90 rounds

Fire rate800 shots/min

The BI is armed with:

• 2 x 20 mm ShVAK cannons, nose-mounted (45 rpg = 90 total)

Usage in battles

Fuel management

Managing your fuel will allow your endurance to increase from 1 minute 57 seconds to over 13 minutes, only use the fuel you need to use.

To get the longest endurance out of its limited fuel amount, climb from the airfield at an angle of 70-80 degrees, at full throttle and as you hit 3,000 m, change the angle of the attack and throttle back to 30%. Adjust your climb angle to make sure that both speed and altitude continue increasing. This will allow you to travel to 5,000+ m without burning too much of your precious rocket fuel, you will need this for later in the battle. Once you have hit 5,000 m, throttle back to 14% and continue to climb and adjust your climb angle again to roughly 16 degrees. You can continue to climb at this angle until you see it fit not to do so.

When you hit the altitude you like, you can throttle back to 0% and just glide, with only minor adjustments to the throttle to stay in level flight.

Descending

The key to descending without locking up and crashing is to not point your nose straight down. Unlike other aircraft, the BI is able to gain a lot of speed even in a little descent. When the BI starts going over 700 km/h, pull up slowly and slow back down. When you push the nose back down, push the rudder all the way to the left or right. If you aren't losing speed fast enough, shift the plane 45 degrees to the left and right, with full rudder movements. This will slow you down.

Due to the BI being able to go over 900 km/h with ease and locking up at Mach 0.76, descending from height from 5,000 m needs to be carefully calculated based on the battle conditions in the match. If you descend to fast, due to a high angle of attack, you will lock up and crash into the ground, because you will be unable to pull out in time.

A high angle of attack for a descent is around -70 degrees, even using the ruder and shifting the BI to the left and right will not be enough.

A good angle of attack to descend is around -30 to -60, the steeper the angle faster you will go. When you descend keep your throttle at 0%, only when you are pulling out of the dive at the very end, after losing speed, they should be opened carefully.

Engaging in combat

Cockpit of the BI.

The BI is similar to the Me 163 B - small amounts of fuel and ammo (low flight endurance) but with astonishing performance, being able to climb 80 degrees vertically. As such it excels in the interceptor role, climbing at a extremely high rate of up to 116.4 m/s in AB and 100 m/s in RB. Able to shoot down bombers and fighter bombers before exhausting the fuel supply and landing again. Don't be fooled by its acceleration into thinking it has a high top speed - the wings and elevators will lock up at Mach 0.76, making any manoeuvres impossible. Flying full throttle at 8,000 m will see you rip your wings off in level flight.

If engaged by an opponent, do not try to outrun them, instead use your manoeuvrability and acceleration to turn fight, your speed and small size are your greatest strengths. The BI only has 90 rounds of ammo, 45 rounds per gun. This is not a lot of ammo, so take care to make every shot count.

Engaging fighters

Fighting fighters in combat, aim for the wings and tail, aiming for wings with the limited ammo which the BI has will cause the wing fuel tanks to catch on fire. Aiming for the tail, will see that the tail gets cut clean from the fuselage, unlike a bomber a fighter is smaller and has less space for fired ammo to miss critical elements.

If the enemy fighter notices you attempting to sneak up on them, they will bank left or right, do not follow them in the turn, the BI cannot turn fight without losing its advantageous speed. Instead, disengage, throttle up, climb and come back around for another pass.

Engaging Bombers

Fighting bombers, aim for the wings and engines, aiming for the fuselage is unlikely to cause any critical hits unless you can hit the flight deck. Aiming for the wings increases the odds of hitting a wing spar and seeing the wing get ripped off with a short salvo. Aiming for engines will knock them out and possibly set fires inside of the wing-installed fuel tanks. The larger area with more critical elements increase the odds of doing critical damage with the limited rounds which you have.

Do not stay behind the enemy bomber, their gunners will hit your rocket fuel tanks and will see the BI set on fire. If this occurs, break off the attack and dive as fast as you can, this will put the fire out. Then head back to the airfield and repair, and refuel.

Landing

To land the BI, you should keep about 5 to 10 seconds of fuel in case you need to go around due to a missed approach. When on approach, you will need to lose speed fast, which it can do. This is due to the BI not using the sleek low profile aerodynamic wings, as you find on other jets. However, to do this, you must reduce the speed down to under 420 km/h or your gear will be ripped off making the odds of crashing on landing very high.

To land the BI, flip the plane on its side, use the rudder during the turns to help cause more fiction with the air, which will start reducing its speed. Due to the shape of the BI which features great glider aerodynamics, it is able to fly at high speeds and keep the momentum even without any throttle being active. As soon as the BI touches the ground, apply the breaks and turn the rudder hard left and right to help slow it down.

Landing on short runways should be avoided or risk crashing at the end, the reason for this if you come into fast or high the BI will bounce, it will bounce to 150 m or more. Ideally you should head back to the main airfield which has the long landing strip to land on.

BI attacking an enemy jet bomber.

Pros and cons

Pros:

• Amazing acceleration
• Great roll rate
• Excellent manoeuvrability
• Incredible climb rate; can climb at a whopping 70° when spaded
• Very small size makes successfully hitting it troublesome

Cons:

• Not very well armoured
• Only has landing flaps
• Can reach rip speed (Mach 0.81) while travelling in a straight line
• Very hard to pull out of a dive due to its great speed
• Maximum fuel load is only 1 minute and 57 seconds
• Very limited armament, only two ShVAK cannons with 45 rounds each

History

Test Flight Log:

Date	Place	Pilot	Issues
October, 1941	Lake Bilimbay	Grigory Yakovlevich Bakhchivandzhi	None
April, 1942	Koltsove Airfield	Grigory Yakovlevich Bakhchivandzhi	None
May 15th, 1942 19:02 (UTC)	Koltsove Airfield	Grigory Yakovlevich Bakhchivandzhi	Aircraft was damaged because of a hard landing and the pilot was injured.
March 27th, 1943	Koltsove Airfield	Grigory Yakovlevich Bakhchivandzhi	Aircraft crashed and was severely damaged so the test flights were discontinued.

Devblog

In the early 1940's, the OKB-293 aircraft design bureau began working on a new rocket-propelled aircraft design. The aircraft promised excellent performance figures, although at the expense of range due to the limitations of rocket engines at the time. After the invasion of the Soviet Union in June 1941, the design was seen as a potential short-range interceptor design to protect vital Soviet land installations from air raids. Thus, the project was approved for further development work and testing.

Development of the aircraft continued, with several prototypes being made and test flown. However, rapid advancements in aviation technology, especially the appearance of the jet engine, during the war outpaced the development of the BI. Therefore, the aircraft never left the prototype stage and didn't take part in active combat. Instead the aircraft's development served more as a testbed for Soviet rocket propulsion research, with the insights gained being later used for other projects during the Cold War.

Media

Skins

• Skins and camouflages for the BI from live.warthunder.com.

Images

• BI Devblog Images
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Videos

Rocket Planes discusses the BI at 00:40 - War Thunder Official Channel

Most unusual aircraft discusses the BI at 3:44 - War Thunder Official Channel

A BI... to fly - Napalmratte

The Shooting Range #218 - Metal Beasts section at 00:28 discusses the BI.

🅱️i video - Rulo6000

See also

Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:

• reference to the series of the aircraft;
• links to approximate analogues of other nations and research trees.

External links

• [Devblog] Crafting Event "Strategist": Bereznyak-Isayev
• [Wikipedia] Bereznyak-Isayev BI-1