Whifferdill turn

A whifferdill turn[1] (also wolferdil, whiferdill, or (chiefly Canadian & British) whifferdale or wifferdale manoeuvre) is any of a number of aerobatic maneuvers performed in an aerial flight show or while flying aggressively.

It is a turn with both horizontal and vertical components, usually performed at the end of one maneuver in preparation for the next.

The whifferdill is a basic aerial warfare maneuver that is used to reverse course in a dogfight with very little loss of energy/airspeed.

Due to the short time and positional requirements, the maneuver uses a significant amount of fuel and can be difficult to execute successfully.

In the case of Gemini 10 the need for the maneuver was a result of misalignment of the inertial guidance platform, causing axial drift of the approach trajectory, prior to closing to docking distance.