Tupolev's TB-3 4M-17

IkranMakto · April 4, 2020

9 days of quarantine, 9 days of work... It'm tired, but I present... Hope you enjoy it!

TB-3 4M-17 with Breaking Ground and B9 Procedural Wings in KSP 1.9

A replica of soviet heavy bomber plane Tupolev TB-3 4M-17 (1933) on a 2/3 scale

https://kerbalx.com/IkranMakto/TB-3-4M-17

It’s an early model of this plane equipped with licence engine copy of BMW VI called M-17 (705 hp)

How to take-off with full weight? Instructions for default controls:
1) Throttle to 0, smooth control(Caps lock);
2) Push 1, 2, 3 and 4 in any order to start engines, let them spin and start idling. You can fly in any combination if enough thrust;
3) Plane may start rolling, don’t worry. Real one was not fitted with brakes. It should slow down by itself if you land it on grass or dirt.

4) Add throttle and control yaw, at 14 m/s it should rise its tail
5) Slightly pull up when above 28 m/s
6) You fly! Don’t rise nose above 5 degrees, just get enough speed and you can start second part….

How to fly and balance vechicle to minimize control input? Use trims!
Vertical translate (I and K) slowly changed stabilizer pitch from -4 to +4 degrees.
Horizontal translate (J and L) changes neutral position of tail rudder from -7 to +7 degrees.

Action Groups:
1, 2, 3 and 4 - start/stop engines
0 - side door, hatch and ladder toggle
9 - bomb bay doors toggle
8 - drop bombs

Specifications:

Max speed
Ground level - 52 m/s (185 km/h)
At altitude - 54 m/s (194 km/h)
Min speed(stall) - 18 m/s (65 km/h)
Take-off speed - 24-29 m/s (86-100 km/h)
Landing speed - 22-25 m/s (80-90 km/h)

Empty weight - 9818 kg
Fuel weight - 2040 kg in 2 tanks (223 LF and 183 LOX)
Bomb weight norm - 3200 kg
Bomb weight max - 4000 kg
Max take-off weight - 15000 kg

Length - 16.25 m
Wingspan - 26.60 m

Engine:
A small BG’s motor equipped with 2-blade fixed pitch(wooden) propeller. I did some thicks to make it as much realistic as possible. When running RPM limit always set to 430 rpm, but engine it won’t reach that speed. I fought a lot with this strange physics because higher AoA somehow doesn’t mean higher drag.

Idle - 110-130 rpm
Cruising - 300-350 rpm
Max power - 400-420 rpm
Propeller - 2.3 m

Flight time > 8 hours
Climb rate 1-4 m/s depends on load