Its nearly identical to the 121 Heavy except for a few differences:
1: The controls feel a bit heavier
2: The engines produce much less power
3: Its a flying torpedo boat now

And I use this and a few other planes to test weapons, build techniques and roundels/flags/insignias.

Activation groups 1-4: (De)Activates engines 1-4
Activation group 5: Control dampener. Only use when in flight.
Activation group 6: Fire torpedoes
Activation group 7: (De)Activates) flaps
VTOL slider to control propeller pitch
Trim slider to control flaps and trim

Takeoff instructions: VTOL slider 1/2 up. 100% power. Trim at whatever you want except for up. Pull up at 150 mph.

Cruise instructions: VTOL slider 1/2 up. 70% power at 30,000 feet. Activation group 5 if you don't want to keep messing with the controls.

Final approach. Just keep the VTOL slider at 1/2 and the speed at 200 mph.

Landing: Flaps down. VTOL slider at 1/2 up. Pitch up to 5 degrees and descend at around 3 m/s until you hit the runway. Brake if you feel like it. if not, just set the VTOL slider to 1/2 down and the throttle to 80% until you stop.

AND DON'T HOLD THE BRAKES OR YOU'LL GO TO GULAG.
Just tap on it lightly.
if not, the plane will bounce. And so will you to the gulag.

prop control guide:
VTOL slider 1 up=No thrust produced/prop feathered
VTOL slider 0 centred=No thrust produced/high RPM
So find a position between 0-1