split S

Meanings

1. An aerobatic maneuver in which an aircraft, starting from upright level flight, rolls inverted and then performs one-half of an inside loop, ending up in upright level flight in the opposite direction at a lower altitude; equivalent to an Immelmann turn (modern sense) performed in reverse.

Etymology

Named for the resemblance of the aircraft's flightpath to the upper or lower half of the letter S (an aircraft performing two split Ses in sequence, with the first split S leading immediately into the second, would trace out a flightpath in the shape of a vertical S).