A whifferdill turn[1] turn (also wolferdil or whiferdill) refers to any number of fancy 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. As the plane is climbing the pilot makes a turn reversal, and as the plane descends it is turned so that it can make its next maneuver.
Pilots often use the term as slang for any multi-axis movement.
The Whifferdill is a basic aerial warfare maneuver that is used to reverse course in a dogfight with very little loss of energy/airspeed. It is also a fundamental maneuver used in air shows.
In astronautics, a whifferdill is a maneuver used during orbital rendezvous when the target is on a different orbital plane from the piloted vehicle. Due to the nature of orbits, the target will seem to make a helical like motion relative to vehicle as the orbit progresses. A wifferdill maneuver is used to realign the orbital plane of the vehicle with the target in a short time space and stay near the targets orbital position or mean anomaly. Due to the short time and positional requirements the maneuver uses a lot 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.[2]