Spire AFOQT 4.1.3 Airplane Aerodynamics

Critical Angle of Attack

The point at which airflow over the wing becomes turbulent, leading to a stall

Recovery from a stall

To recover from a stall, pilots must reduce the angle of attack, typically by lowering the aircraft’s nose. This restores smooth airflow over the wings, allowing the aircraft to regain lift.

Parasite Drag

Caused by the aircraft’s structure and surfaces interacting with the air. Streamlining the aircraft minimizes this form of drag. Design features such as retractable landing gear and smooth fuselage contours contribute to reducing parasite drag.

Induced Drag

A byproduct of lift production. It increases as the angle of attack increases, such as during slow flight or high angles of climb. Like gliders, wings with a high aspect ratio experience less induced drag. Aspect ratio is the ratio of the wingspan to the mean chord (average width) of the wing. The wingspan is the distance from wingtip to wingtip, and the mean chord is the average width of the wing from the leading edge to the trailing edge.

Ailerons

Hinged control surfaces on wings. Control roll (tilting, banking left or right). When a pilot deflects the ailerons, the left on one wing increases while decreasing the other, initiating a roll about the longitudinal axis.

Elevators

Govern the aircraft’s pitch. Typically found on the horizontal stabilizer at the tail. Controlled by the yoke or control stick, movement in the elevators results in a change in the aircraft’s nose position. Pulling back raises the nose, initiating a climb, while pushing forward lowers the nose, prompting a descent. Elevators are crucial for controlling the aircraft’s altitude.

Rudder

Controls yaw. Mounted on the vertical stabilizer at the tail.

Flaps

Located on the trailing edge of the wings, deployed during specific phases of flight to augment lift and control. Extended flaps increase wing area during takeoff and landing, providing additional lift at slower speeds, which allows for shorter takeoff distances and lower landing speeds.