Immelmann turn

The Immelmann turn refers to two quite different aircraft maneuvers. The maneuver nowadays usually called an "Immelmann" has, in fact, no connection with the World War I German flying Ace Max Immelmann and is quite different from the historical fighter tactic.

In Aerobatics

In modern aerobatical parlance, 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, and is a different maneuver altogether from the original dogfighting tactic of World War I from which it derives its name.
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.

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.

It should be stressed that 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. (Immelmann's Fokker Eindecker most certainly did not).

The Immelmann turn has become one of the most popular aerobatic maneuvers in the world, being commonly used in airshows all over the world. However, the aerobatic maneuver is of little use in modern dogfighting, because modern high thrust fighters can quickly initiate sustained vertical maneuvering from level flight, and slow targets are highly vulnerable to air-to-air missiles. The aerobatic maneuver also involves rapid "energy loss" (loss of airspeed) even if the nose is pushed down sharply as the maneuver is completed (This maneuver, an aerobatic Immelman followed by a dive back to the original altitude is another aerobatic maneuver called the "Half-Cuban-Eight").

The Immelmann is contrasted with 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.

Historical combat maneuver

In any case, the World War I "Immelmann turn" was a far less polished maneuver. This attacking maneuver was quite possibly used by Max Immelmann and may even have been originated by him. It was certainly used by other World War I fighter pilots, who called it after him.

After making a high speed diving attack on an enemy, the attacker would then zoom climb back up past the enemy aircraft, and just short of the stall, apply full rudder to his aircraft around. This put his aircraft facing down at the enemy aircraft, making another high speed diving pass possible. This is a difficult maneuver to perform properly, as it involves precise control of the aircraft at low speed. With practice and proper use of all of the fighter's controls, the maneuver could be used to re-position the attacking aircraft to dive back down in any direction desired. This form of "Immelmann turn" was called "Renversement" by French pilots. The modern aerobatic maneuvers that most resemble the World War I Immelmann are the "wingover", and the "hammer-head turn".

As a practical combat tactic, the Immelmann had already fallen somewhat into disfavor by 1917/1918, as it became obvious that the zooming aircraft presented an easy target as it hung nearly motionless at the top of the maneuver - provided the aircraft under attack was sufficiently powerful and well armed to follow his adversary, or was fitted with flexible forward and upward firing guns. The Immelmann could still be used in World War II by fighters attacking unescorted bombers that could not follow the fighter up into the climb, as long as the zoom climb took the fighter beyond the range of the bomber's defensive guns.

In popular culture

*Singer-songwriter Al Stewart included a song entitled "The Immelman Turn" on his 2005 album "A Beach Full of Shells".
*Claus Valca of the anime "Last Exile" gets nicknamed "Immelmann" by Dio Eraclea for his successful execution of an Immelmann turn.
*In the climax of the 1983 movie "Blue Thunder", main character Frank Murphy (Roy Scheider) uses an Immelmann turn with his helicopter to defeat his arch enemy Col. Cochrane (Malcolm McDowell).
*In the PC video game H.E.D.Z., the 'hed' player characters that possess the ability of airplane flight can perform an Immelmann turn using the special controls.
*In the PC video game Wings Of War Immelmann turn is one of the standard maneuvers the player can execute using special controls.
*The Immelmann Turn is performed by one of the characters in Thomas Pynchon's novel Gravity's Rainbow.
*The Immelmann turn is one of the maneuvers available to the player in the Nintendo 64 game Star Fox 64.

ee also

* Chandelle
*Split S
*Immelmann loop (Roller coaster element)
*The Scissors
*Dogfighting
*Max Immelmann

References

* [http://www.furball.warbirdsiii.com/krod/ACM-immelman.html The "Immelman" Turn]

"This article has been simplified for civilian reference."