Immelmann Turn - Aerobatic Maneuver

Aerobatic Maneuver

In modern aerobatics, an Immelmann turn (also known as a roll-off-the-top, or simply an Immelmann) is an aerobatic maneuver of little practical use in aerial combat. Essentially, the aerobatic Immelmann comprises an ascending half-loop followed by a half-roll, resulting in level flight in the exact opposite direction at a higher altitude.

The aerobatic Immelman turn derives its name from a different maneuver altogether—the dogfighting tactic of World War I named after the German pilot Max Immelmann, and described above.

To successfully execute the aerobatic Immelmann turn, the pilot accelerates to sufficient airspeed to perform a loop in the aircraft. The pilot then pulls the aircraft into a climb, and continues to pull back on the controls as the aircraft climbs. Rudder and ailerons must be used to keep the half-loop straight when viewed from the ground. As the aircraft passes over the point at which the climb was commenced, it should be inverted and a half loop will have been executed. Sufficient airspeed 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 aircraft orientation. As a result, the aircraft is now at a higher altitude and has changed course 180 degrees.

Not all aircraft are capable of (or certified for) this maneuver, due to insufficient engine power, or engine design that precludes flying inverted (usually piston engines that have an open oil pan). In fact, few early aircraft had sufficiently precise roll control to have performed this maneuver properly.

The Immelmann turn has become one of the most popular aerobatic maneuvers, being commonly used in airshows all over the world. However, the aerobatic maneuver is of little use in modern dogfighting.

Sometimes called a "reverse" or "inverted" Immelmann is the Split S maneuver, which is a half-roll followed by a descending half-loop, resulting in level flight in the exact opposite direction at a lower altitude.