An Immelmann turn is an aerobatic and spaceflight maneuver, in which a craft flying on a level climbs through a 180 degree loop, then executes a half-roll, the result being a reversal of direction at a higher altitude. Samir al-Halak executed an Immelmann turn while trying to evade Orion Syndicate ships after leaving Ryn III. (TLE novel: Well of Souls)