Fastener slide. Zipper.

Federal Aviation Administration (FAA). An organization within the Department of Transportation. The FAA establishes aviation rules and regulations, as well as enforces those policies. The purpose of the FAA is to set the standards for civil aircraft in the interest of public safety.

Feed dog. A mechanical device located under the throat plate of a sewing machine that feeds the material through a sewing machine.

Ferrule. Device that provides a strong and smooth finish on the ends of a ripcord housing.

Fid. A small, flat, tapered bar of metal or wood used to insert the corner flaps into the container when packing.

Finger trap. A method of attaching or splicing lines by inserting one line into another. Used primarily on hollow braided lines.

Finish. The condition of the parachute fabric caused by the application of heat and pressure whereby the fibers are forced closer together. This treatment is used to determine the permeability of the fabric.

Fish scale. A spring scale used to measure the ripcord pull force or fabric strength test.

Folder. A device used as an attachment to a sewing machine to guide and fold fabric.

Force. A push or pull that tends to change the velocity or direction of a body’s motion.

Forging. A high-pressure shaping of hot metal. The process used to make parachute hardware.

Forward speed. The rate at which a parachute moves horizontally in a mass of air.

Four line check. On a round canopy, the four lines that run to the top center and bottom center gores. Used to check the line continuity. On a 28-foot canopy, they are lines 1, 14, 15, and 28.

FPS. Feet per second.

Free bag. A type 5 reserve deployment device used with ram-air canopies. Not attached to the canopy, it is designed to allow deployment of the canopy in the event of a horseshoetype malfunction.

Free fall. A parachute jump in which the parachute is activated manually at the discretion of the parachutist.

French fell seam (LSC-2). A plain overlap where material is folded over on itself and stitched to prevent raveling.

Friction burns. The result of two textile surfaces rubbing together rapidly and generating frictional heat, which reduces the tensile strength of the textile and causes deterioration of the individual threads; it occurs primarily during parachute deployment and initial inflation.

G force. The measure or value of the gravitational pull of the earth as modified by the earth’s rotation, equal to acceleration of a freely moving body at the rate of 32.16 feet per second. Example: If a 100-pound load places a 300-pound stress on the parachute during opening, the shock is 3 Gs.