Avia B-135 Performance

[Laurelix]

Avia B-135

General Data:
Wingspan: 10.85m
Length: 8.50m
Height: 2.60m
Wing Area: 17.00m2
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Engine: H.S 12Ycrs
775CV at Sea Level (880mmHg)
850CV at Sea Level (960mmHg)
860CV at 3300m (880mmHg)
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Empty Weight - 1906kg
Fuel - 234kg
Pilot - 80kg
Parachute- 10kg
2x 7.92mm Vz.30 - 24kg
2x 450 rounds - 30.6kg
Aimer - 0.35kg
1x 20mm MG/FF - 43kg
60 rounds - 25.7kg
Radio Equiptment - 24.5kg
With addition of other accessories the loaded Weight of the plane was 2421kg give or take.

Surface of Ailerons: 1.15m2
Wing Chord Max: 2.117m
Landing Flap Angle: 55 degrees
Horizontal Tailplane Surface: 2.234m2
Horizontal Stabilizer Surface: 1.152m2
Elevator Surface: 1.082m2
Vertical Tail Surface: 1.462m2
Fin Surface: 0.480m2
Rudder Surface: 0.982m2
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Aileron Deflection
Up: 16 degrees
Down: 11 degrees
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Elevator Deflection
Up: 27 degrees
Down: 24 degrees
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Trip Tab Deflection
Up: 19 degrees
Down: 20 degrees
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Rudder Deflection
Left: 28 degrees
Right: 28 degrees

According to Bulgarian Tests conducted in 1942, the top speed at Maximum Power (920 mmHg) At 2447kg Weight was;

462km/h at Sea Level
478km/h at 1000m
495km/h at 2000m
511km/h at 3000m
527km/h at 4000m
529km/h at 4150m
519km/h at 5000m
507km/h at 6000m

Other tests and sources reach as high as 535km/h at 4000m (Probably with 960mmHg)

Rate of Climb According to Czechoslovak Tests
At 2421kg Weight:

Time to 1000m: 1:26
Time to 2000m: 2:47
Time to 4000m: 5:35
Time to 5500m: 8:40

Other Tests and sources state as good as
1:14 to 1000m

Maximum Safe Dive Limit:
According to the test flight on 3rd July 1941 the plane dove to 715km/h, even at this speed the controls were easily handled and the pilot didn't notice any vibrations. According to Airwar.ru the maximum safe dive limit is 804km/h IAS.

Armament:
Initial Production:
1x 20mm Oerlikon FFS - 60 rounds total [Motor-Cannon]
2. 7.92mm Vz.30 - 900 rounds total [Cowling]

Further Productions after capitulation:
1x 20mm MG/FF - 60 rounds total [Motor Cannon]
2x 7.92mm Vz.30 - 900 rounds total [Cowling]
———————
• Weapon Specification:
- Aerial 7.92mm Vz.30
Rate of Fire: 1000RPM
Muzzle Velocity: 860m/s
Cartridge: 7.92mm x 57mm Mauser

- 20mm Oerlikon FFS
Rate of Fire: 470RPM
Muzzle Velocity: 830m/s
Cartridge: 20mm x 72mm

- 20mm MG/FF
Rate of Fire: 520RPM
Muzzle Velocity: 585m/s
Cartridge: 20mm x 80mm

Bomb Ordinance Options:
(The following Bombs are Škoda General Purpose HE bombs)
Option 1:
2x 50kg (Rack Under Fuselage)

Option 2:
1x 100kg (Rack Under Fuselage)

Option 3:
6x 10kg or 20kg Bombs (Rack Under Fuselage)

I calculated the stall speed of this plane also:
Loaded at 2421kg , 1000m alt, no flaps , 1.4 CL_Max Wing Lift Coefficient
145km/h IAS
It's initial turn Rate is somewhat worse than an the earlier light weight I-16 but it will turn right inside of BF-109E with ease. This is a sustained turn time of roughly 16 seconds which is A6M5 level good.

Skins:

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Sources:

• Kučera, P.; Bílý, M.; Bernád, D. (2003). Avia B-35/B-135 (in Czech/English). Praha, Czech Republic: MBI. ISBN 80-86524-03-5.

This book also contains direct images of primary source such as the Bulgarian top speed results.

• Československé stíhací letouny, Pages 94-96

ISBN: 8026418093, 9788026418092

• www.airwar.ru/enc/fww2/av135.html

 

[Laurelix]

Corrected the HS.12Ycrs Power Curve

 

[Laurelix]

Got a Higher Resolution of it

 

[special ed]

Great find. That chart is on page 59 of my Avia book (MBI -Bily, Bernad, Kucera) and I never paid attention. Although I had begun to cut balsa for a flying model, I am afflicted by the same malady as most of the members with their plastic models. I'll finish it "soon".