Defined as the overall shape of the wing using the top view perpendicular to the chord line with the canopy laid flat. Defined as the product of the finished chord times the finished span of the canopy. The plumb line is used only to locate a reference system that may be quickly and easily determined for any parachute. The area of the inflated canopy as view from above, perpendicular to the chord line at the centerline of the parachute. Due to canopy curvature and cell inflation bulging the projected area is always smaller than the planform area.
Usage is equivalent to aircraft practice of using the aircraft centerline as a reference line.
The sections of fabric installed between the top and bottom surfaces of the canopy and used to establish the airfoil shaped of the canopy. Most canopies have both loaded and non-loaded ribs. The suspension lines are attached to the loaded ribs at the line attachment points. Used as a reefing device on ram-air parachutes. During deployment, the canopy is reefed as the spreading force of the canopy is resisted by the slider which is held up against the lower surface of the canopy by the airflow.