Glossary A B Apex.  The center and topmost point of a round  parachute canopy. Accordion folding.  The folding of the canopy for stacking in the container prior to closing. Approved.  An item, which in its present form, has received  official certification from the FAA. Administrator.  The Federal Aviation Administrator (FAA)  or any person to whom he and/or she has delegated his and/ or her authority in the matter concerned. Assistor pocket.  Air scoops at the top of a sleeve that provide  drag and aid in anchoring the sleeve as the canopy is pulled  out. Also, fabric pockets on the bridle of a free bag that aid  in the deployment of the bag in the event of a horseshoetype  malfunction. Advisory circular (AC).  The FAA issues advisory  circulars (ACs) to provide guidance and information in a  designated subject area or to show a method acceptable to  the Administrator for complying with a related Title 14 of the  Code of Federal Regulations (14 CFR). Each AC is issued  with a number corresponding to the subject it addresses in the  14 CFR. Unless incorporated into a regulation by reference,  the contents of an AC are not binding on the public. Automatic activation device (AAD).  A device for  automatically releasing the reserve or emergency parachute;  utilizes barometric and rate of descent sensors. Auxiliary parachute.  A reserve parachute. Aerodynamics.  The study of the behavior of moving air  and the forces that it produces as it passes over or around  certain shaped objects, such as wings, propellers, or  parachute canopies. Back parachute.  A parachute that is worn on the back. Backstitch.  Used to anchor a row of stitching by turning the material and sewing over the stitching for a short distance. AGL.  Above ground level. Airframe and powerplant mechanic (A&P).  Any  person certificated by the FAA to perform maintenance or  inspections on an aircraft’s airframe or powerplant. Back strap.  A part of the harness that extends across the wearer’s back. It may be diagonal, horizontal, or vertical and  may or may not be adjustable. Backpad.  A foam-filled pad placed between the harness and  the wearer that provides comfort and/or holds the harness  in place.  Airworthiness Directives (ADs). Issued by the FAA to  notify owners and users of aeronautical products of unsafe  conditions and the mandatory corrections under which the  product may continue to be used. Each AD is an amendment to  14 CFR part 39, as such, it is part of the Federal Public Laws. Bar tack.  A concentrated series of zigzag-like stitches used to reinforce points of stress. Barometric pressure release.  A device of the automatic  opening of a free-fall parachute operating on the differences  of barometric pressure. Airworthiness.  A complete parachute assembly is considered  airworthy when it conforms to its Technical Standard Order  (TSO) and/or properly altered condition and is in condition  for safe operation. Alteration.  A change to the original configuration or any  other major change to any portion of the parachute from its  original manufacture’s specifications. Becket.  A piece of tape or webbing sewn to a parachute or pack  to form a loop through which a cord or thread may be passed. G-1