Flap extension significantly affects an airplane's lift characteristics, particularly concerning where the lift is generated and the subsequent impact on pitch.
Lift Generation with Flaps
Extending flaps increases the wing's camber, which is the curvature of the airfoil. According to aerodynamic principles, this increased camber from flap deflection produces lift. Essentially, by making the wing more curved, flaps help the wing generate more lift, especially beneficial at lower airspeeds.
Location of Increased Lift
A specific effect of flap deflection, as noted, is that the increased lift produced by the additional camber is generated primarily on the rear portion of the wing. This shift in the lift distribution towards the back of the wing has a notable consequence on the aircraft's handling.
Impact on Aircraft Pitch
Because the significant increase in lift occurs mainly on the rear of the wing, it creates a moment that pushes the tail down or the nose up relative to the point where the main lift used to be centered. Consequently, this localized lift increase produces a nose-down force on the airplane. It's important to remember that this pitch behavior varies on different airplane designs, as other factors like horizontal stabilizer design and location can influence the overall pitching moment.
Summary of Flap Effects (Based on Reference)
Based on the provided information, extending flaps affects lift in the following ways:
- Flap deflection, by increasing camber, produces lift.
- This increased lift is generated primarily on the rear portion of the wing.
- The lift increase on the rear portion of the wing produces a nose-down force.
- The resulting pitch behavior varies on different airplane designs.
