Camber is the curvature of an airfoil's upper or lower surface, measured from the leading edge to the trailing edge. Greater camber generally produces more lift at a given airspeed and angle of attack.
How It Works#
An airfoil sits between two imaginary lines: the chord line (a straight line from leading edge to trailing edge) and the mean camber line (a curved line running through the midpoint of the airfoil's thickness). Camber is the maximum distance between these two lines, expressed as a percentage of the chord length.
When air flows over a cambered surface, it travels a longer path across the upper surface than the lower. This accelerates the airflow on top, which lowers pressure there. The resulting pressure difference between upper and lower surfaces generates lift, the aerodynamic force that keeps the aircraft flying.
A symmetrical airfoil has equal upper and lower curvature, so the mean camber line and chord line are the same. It produces no lift at zero angle of attack. An asymmetrical airfoil curves more on top, generating lift even when flying level. Most general aviation wings use asymmetrical profiles for this reason.
Pilots can also change camber in flight. Extending flaps increases the wing's camber, boosting lift and drag at lower airspeeds. This is why flaps help during takeoff and landing.
Example in Aviation#
A Cessna 172 uses a cambered wing profile. During cruise, the wing generates enough lift to support the aircraft with modest angle of attack. When the pilot extends flaps on final approach, the effective camber increases. The wing now produces more lift at a lower airspeed, allowing a slower, more controlled descent to the runway.
Why It Matters#
Understanding camber helps pilots make sense of how their aircraft behaves in different configurations. It explains why flaps change stall speed, why some aerobatic aircraft can fly inverted comfortably, and why wing design varies so much between a glider and a jet fighter.
For student pilots, camber is the foundation of lift theory. Grasping this concept makes other aerodynamic principles, such as stall, angle of attack, and flap operation, far easier to understand.
Key Takeaways#
- Camber is the curvature of an airfoil between its leading and trailing edges.
- Greater camber produces more lift, but also more drag.
- The mean camber line traces the midpoint of the airfoil's thickness from front to back.
- Symmetrical airfoils have zero camber and produce no lift at zero angle of attack.
- Flaps increase effective camber, raising lift and lowering stall speed during takeoff and landing.