Angle of Attack

Angle of attack is the angle between the wing’s chord line and the oncoming airflow. It strongly influences both lift and drag. Flaps increase the wing’s camber to improve low-speed performance. A stall occurs when the airflow separates from the wing’s upper surface.

Assumptions

This simulation shows a simple wing shape like the one used on a small airplane called the Piper Cub. You can change the angle of attack, how much the flaps are lowered, and the airspeed. Watch what happens to the air flow and the lift and drag forces.

Use the screen to compare smooth air flow, flaps for extra lift at slow speeds, and stall behavior. The black test area keeps everything easy to see so you can focus on the aerodynamic changes.

AoA: 0.0°
Cl: 0.00
Cd: 0.000
L/D: 0.0
Low Pressure (upper surface)
High Pressure (lower surface)
ATTACHED FLOW — NORMAL FLIGHT
Angle of Attack
AoA 0.0°
Flap Deflection
Flap
Airspeed
Speed 33%

What You Are Seeing

Vocabulary

Angle of Attack

The angle between the wing’s chord line (a straight line from leading edge to trailing edge) and the oncoming airflow (relative wind). Increasing the angle of attack generally increases lift up to a critical point, beyond which the wing can stall.

Attached Flow

Smooth airflow that follows the contour of the wing surface. Attached flow creates the organized pressure distribution needed for efficient lift generation and predictable handling.

Lift

The aerodynamic force produced by the wing that acts perpendicular to the relative wind. It counters the aircraft’s weight and is essential for flight.

Drag

The aerodynamic force that acts parallel to the relative wind and opposes the motion of the wing through the air. Drag increases with angle of attack and flap deflection.

Stall

A sudden loss of lift that occurs when the angle of attack becomes too high, causing airflow to separate from the upper surface of the wing. Stall is caused by angle of attack, not airspeed.

Flaps

Trailing-edge devices that increase the wing’s camber (curvature) when lowered. Flaps allow the wing to generate more lift at low airspeeds, which is critical for takeoff and landing.

Coefficient

Dimensionless numbers (Cl for lift, Cd for drag) that describe a wing’s aerodynamic performance independent of size or speed. They allow engineers to compare different designs under the same conditions.

L/D Ratio

The lift-to-drag ratio. A higher value indicates better aerodynamic efficiency, meaning more lift is produced for each unit of drag. This is a key measure used in aircraft design.

Pressure Distribution

The pattern of air pressure around the wing. Lift is generated by the net difference between lower pressure on the upper surface (blue glow) and higher pressure on the lower surface (red glow).