This is very important to canopy pilots because in essence it means that any sudden, radical maneuver greatly reduces the lifting efficiency of the foil by reducing form lift. Thrust and Weight For a wing to move through the air and produce lift, there must be some force propelling it. Normally this is called thrust. In an airplane it is easy to understand - the engine does the work. With a sport parachute gravity is the engine.
Air is deflected towards the back of the wing, causing forward speed.
The wing is sliding, like a sled on a hill, down a slope determined by the trim of the suspension lines. The more the weight pulls down, the more thrust you get. This can lead a pilot into the assumption that wing loading remains constant, and in straight and level flight this is true. However, wing loading can change dramatically during a turn. To illustrate the concept simply think of a weight swung on the end of a string.