Here some info about the torpedoes.
WWII aerial torpedoes were delicate equipment that needed be dropped with some precautions. Each torpedo type had an optimum altitude and speed of drop that allowed it to hit the water with a determined, optimum angle. If the angle was bigger, the torpedo tended to sink. If it was smaller, it did not enter the water and skipped on the surface. Also, the torpedo could not be dropped from too high altitude, because if it impacted the water too hard, its internal mechanism could be damaged. Each torpedo type in IL-2 has its optimum drop parameters, of course some error is allowed, but not too much.
LT F5W (Italian Whitehead) 100m, 300Km/h
LT F5B 40m, 250Km/h
Mk13, Mk13a 30m, 205 km/h
Mk13 late 180m, 400 km/h
Type91 30m, 240 Km/h
Type91 late 60m, 330 km/h
45-17 30m, 205 km/h
Also torpedoes had to run for some time into the water to arm their warhead, so torpedoes cannot be dropped too close to the ship (distance should be bigger tan 400-600 meters). Torpedoes dropped on ground or directly on the ship (without hitting water) will not explode.
This patch also brings two new examples of torpedoes which are circling torpedoes that had to be dropped from a safe height in areas such as harbours that were crowded with enemy ships. These torpedoes run in circles for some time, if no ship was hit they self-destroyed. Motobomba FFF and 45-36AV-A are the circling torpedoes implemented in IL-2. Motobomba FFF (LT 350) This weapon was designed by Italian designers Frefi, Filpa and Fiore (hence the name FFF). The FFF was a 500 millimeters (20 in) diameter electric torpedo. It was dropped from high altitude, a first small parachute was used to stabilize and keep a low fall velocity; around 200 m of height, a bigger parachute deployed, to assure a softer impact into water. The torpedo was designed to steer concentric spirals until it found a target. It weighed 350 kilograms, and contained a 120 kilograms warhead. Its speed was about 15 knots and it had an endurance of 15–30 minutes.
ToKG device is like a simplified torpedo data computer found in submarines. ToKG sets the torpedo gyro angle which turns the torpedo once it enters the water. For example angle +30 would turn the torpedo 30 degrees to right. ToKG needs two input parameters from the player. Target ship’s speed in knots and ship’s AoB (Angle-on-Bow). ToKG is used with the old bombsight speed & side slip keys. Speed keys are used to input target ship’s speed in knots to ToKG. Side slip keys are used to input ship’s AoB (Angle-on- Bow). Optional spread parameter can also be adjusted with bombsight angle keys. Increasing spread angle means that torpedoes will have different paths and therefore chances of hit can increase. Setting a spread of 6° means that left side torpedo will curve 3° to left and right side torpedo will curve 3° to right. The idea of the ToKG is to input these two parameters to the device which then calculates a correct torpedo gyro angle and feeds it to the torpedo. This way the pilot doesn’t need to estimate the angle and steer plane to take needed lead before the torpedo is released. With ToKG the pilot always aims the plane directly towards the target ship. Anyone who has played submarine simulations, knows that besides target ship’s speed and AoB, distance to the ship has also some effect to the torpedo gyro angle. However when the distance changes, angle remains somewhat constant. The optimum torpedo release distance for ToKG use is 2000 meters from the ship. ToKG can be found from Ju 88A-4/Torp, Ju 88A-17 and He 111H-6 when torpedoes are carried.