Diaper.  Generally, a fabric panel secured by the suspension lines, which is sewn to and wrapped around the canopy. Used to control and reduce opening forces. Found mostly on round reserves. 

Die.  The lower part of the tool used in a press to install snap fasteners or grommets. 

Direct bag static line system.  A static line deployment system where the bag is attached to the static line and the canopy deploys free into the airstream. 

Double throw zigzag stitching. Stitching in which the needle makes a center stitch between each left and right stitch. Also known as a No. 308 stitch. 

Double-W.  A three-point cross-stitch. 

Drop test.  Dropping a dummy or other load from an aircraft in flight or otherwise simulating a live jump to prove serviceability of a parachute. 

Drop zone (DZ).  A specified area upon which personnel or equipment are dropped by parachute. 

Drying tower.  A facility where parachutes are suspended for airing and drying. 

Dual parachute packs.  A sport assembly consisting of a main and a reserve parachute. 

Dummy (parachute).  Torso-shaped dummy of variable weight used for testing parachutes; may be of fixed or articulated construction. 

Dummy drop. A parachute test using a dummy as the suspended load. 

Durable dot fastener.  The common snap fastener used for closing flaps, etc. 

## E 

Ejector type snap harness.  A harness snap that attaches to the V-ring to secure two parts of the harness together. An ejector arm expels the V-ring when the finger-grip lever is pulled outward. 

Emergency parachute. A certificated parachute intended for emergency use. 

End flap.  The fabric on the end of a pack as opposed to the side, used to enclose and protect the canopy. 

End tabs. Metal tabs on the end flap of the pack (principally chest and seat containers) used to secure it closed. 

Eye.  A small steel-wire loop attached to the parachute pack into which a hook on a pack-opening elastic is fastened. 

## F 

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. 

