Stall turn

The speed will decay but before upward motion stops firmly apply full rudder to yaw the aircraft through a cartwheel of 180° until the nose is straight down.

Dive vertically to the same altitude as the maneuver started, then pull out, exiting in the opposite direction.

So as soon as the yaw is established reduce throttle to prevent the aircraft from rolling due to engine torque.

SAR helicopters fly this when hunting survivors or submarines, because it brings the aircraft directly back along the same course to verify the target.

The maneuver doesn't require visual meteorological conditions (VMC) if the pilot is proficient at maintaining altitude by keeping the lateral acceleration ball centered, as any uncoordinated lateral acceleration will induce spatial disorientation.

Sukhoi Su-29 performing a stall turn at the air show in Uppsala , Sweden, 2018.
Aresti Catalog 's notation of stall turn. The aircraft begins at the dot, and pulls into a vertical climb. The small angled line at the top indicates a stall turn (without indicating the orientation after the turn). The plane then descends, pulls into horizontal flight, and ends at the small vertical line.