3D flying involves acrobatics performed while a plane's wings are completely stalled, but the prop backwash can be vectored to achieve control - with the plane shifting in position around what is basically a vertical hovering mode. Planes built for 3D flying may de-emphasize aerodynamic abilities in favor of weight savings and agility, with the ultimate expression of this trend being planes built out of flat foam with no airfoil. 3D flying is distinct from Pattern flying, which involve acrobatics performed in powered flight which rely on lift and momentum, where the plane's forward velocity is large compared to its changes in direction.
Competitions may involve a small box which the plane has to stay within. Control surfaces are only effective due to prop wash blowing back past them. This is functionally similar to a helicopter or multirotor.
These are aerobatics performed in a much larger area, with the common characteristic of high alpha maneuvers (with the angle of attack relative to airflow very high), rather than low-alpha Pattern flying.
This video, by Precision Aerobatics, identifies the following 3D stunt moves:
- Hover - Stationary, pitched +90 degrees relative to normal
- Torque Roll - A hover while yawing
- Wall - A rapid transition from forward flight to a hover, using the wings pependicular to kill forward motion, like a sideways elevator
- Snap to Hover - a rapid transition from forward flight to hovering, like a 'wall', but with +90 yaw and +90 roll to convert horizontal to vertical speed
- Harrier - low-elevation forward velocity while pitched +45 degrees relative to normal
- Rolling Harrier - A harrier while rolling
- Inverted Harrier - A harrier while rolled at a stable +180 degrees relative to normal
- Elevator - A flat orientation dive, stalled but controlled; a harrier while descending
- Flat Spins - An elevator while yawing
- Parachute - a rapid transition from a -180 degree pitch vertical descent to hover, using the wings perpendicular to kill descent rate
- Knife Edge - flying at 90 degrees roll relative to normal, with minimal lifting surface
- High Alpha Knife Edge - a knife edge performed
- Death Slide - A knife edge dive
- Knife Edge Spin - a death slide while pitching rapidly in a near vertical descent
- Inverted Waterfall - A high alpha inverted loop (-360 pitch)