Slow flight

Slow flight is a portion of an airplane's performance envelope above the speed at which the plane will stall, but below the aircraft's endurance speed. This part of the performance chart is also known as "the back side of the power curve" because when flying in this area, "more power is required in order to go slower" and still maintain straight and level flight. A large angle of attack is required in order to maintain the altitude of the aircraft.

At such low speeds, aircraft flight control surfaces begin to lose their effectiveness. Ailerons, in particular, are susceptible. The rudder remains the most efficient flight surface and the adverse effect of yaw which alters pitch is useful for altering the direction of the aircraft without the need for aileron inputs. If the ailerons are used excessively it is probable one wing will stall (due to the increased angle of attack) and send the aircraft into a spin.

Slow flight is also the name given to a training maneuver where a pilot (often accompanied by a flight instructor] flies to a safe altitude and then deliberately slows the airplane to a speed just above its stall speed. This maneuver is valuable in that it teaches the pilot to maintain control of the aircraft in adverse conditions; it requires coordination between hands and feet in order to maintain coordinated flight; and it reminds the pilot of the signs and symptoms of a stall, attuning the pilot to recognize them should they occur in an emergency.

Before practicing slow flight pilots should be sure to check the surrounding area and prepare the aircraft for slow flight. It is a good idea to carry out a HASELL check as it incorporates all the necessary checks. A high amount of rearward trim is required to maintain the nose high attitude, and it is not uncommon for the elevator trim to be set fully rearward, and even then some control column input could be required.

An aircraft is most likely to enter slow flight when carrying out a missed approach at an airfield. This is due to the low air speed, high power setting, and a nose up attitude. To get out of slow flight just apply full power, slowly lower the nose and when the airspeed has built, so you are no longer in slow flight, climb away. Slow flight may also be used as a confidence building exercise for student pilots, instilling a sense of control under conditions that are perilously close to inducing a stall. Such "instructional" slow flights are typically conducted at an altitude high enough for the student pilot (or the instructor) to safely recover the aircraft from a stall or spin.