The AirFriction property of the PlayerController class determines the amount of friction applied to the player when they are airborne. This friction will slow down the player unless a wish velocity is specified. The value is a float and can be adjusted to control how much the player is affected by air resistance.

To modify the air friction for a player, set the AirFriction property to a value between 0 and 1. A value of 0 means no air friction is applied, while a value of 1 applies maximum friction.