An Immelman Turn was an aerobatic maneuver of little practical use in aerial combat. Essentially, the aerobatic Immelmann comprised an ascending half-loop followed by a half-roll, resulting in level flight in the exact opposite direction at a higher altitude. To successfully execute the aerobatic Immelmann turn, the pilot accelerated to sufficient speed to perform a loop in the starfighter. The pilot then pulls the ship into a climb, and continues to pull back on the controls as the spacecraft climbs. As the vessel passes over the point at which the climb was commenced, it should be inverted and a half loop will have been executed. Sufficient speed must be maintained to recover without losing altitude, and at the top of the loop the pilot then executes a half-roll to regain normal, upright spacecraft orientation. As a result, the fighter is now at a higher altitude and has changed course 180 degrees.
There was an older, unrelated maneuver that was very relevant to aerial combat in the era of very low thrust-to-weight aircraft. It would only rarely be relevant in an era of starfighters, and then only in a gravity field.
- Immelmann turn on Wikipedia