My experience with AI torpedo bombers is as soon as you send the signal to attack, they head towards a waypoint parallel to the target's current course. Then they make a final turn on the torpedo run. The problem is the AI doesn't know a basic fact about flying, that pitching up is required when banking to maintain the same amount of lift and thus stay at the same altitude, and this is critical when at the very low altitude for a torpedo run (makes no difference for a bomb run from 4000 feet). The Ju-88 lacks sufficient power to pull up in time from a steep bank (other aircraft are more likely to have sufficient raw power to escape sometimes), so the solution is to lead your aircraft in at a correct angle and issue the attack order at the correct distance, so that a steep bank for the final torpedo run is not required. Since of course the AI's waypoints are not visible to you, it will take some experimentation. In my experience, being perpendicular to within 10 degrees, and about 4-6 miles out is the best time to issue the attack order, and it helps to already be at a lower altitude. Still, some aircraft may crash. Also, other approaches can work, so when you find an approach angle/distance that works for you, always come in from that angle in the future. The faster the target ship's speed, the more difficult it becomes, since the AI sets the initial waypoint based on where the target is at that moment, and the faster the ship, the farther away the airplane will be once it arrives at the waypoint.
