Beeswax.  A wax, usually mixed 1:1 with paraffin and heated. Webbing is dipped into it to prevent fraying. Bellyband.  A reserve tiedown strap. Bias construction.  Construction where the warp and filler  threads of the material are at 45 degrees to the centerline of  the gore. Bias cut.  A diagonal cut across a piece of fabric. Canopy  fabric may be cut on the bias and assembled so that both  warp and fill threads run at a 45 degree angle to the vertical  centerline of the gore. Block construction.  An arrangement of the gores such that  the warp threads are parallel to the peripheral hem. Bobbin.  A small spool used to hold thread. Commonly found  in sewing machines. Bodkin.  A large-eyed needle, flat or round, and usually  blunt, used to draw tape, ribbon, elastic, or cord through  a loop or hem. Used to pull pack opening bands through  containers. Bolt.  A compact package or roll of fabric. Break tie.  Any tie or tacking designed to break under a  specified amount of stress. Breakaway.  The jettisoning of the malfunctioned main  parachute by activating riser releases and deployment of the  reserve parachute; also known as cutaway. Breakcord.  A thread or tape tied between parachute  components that is intended to break under the desired load  during deployment. Bridle.  A line that attaches the pilot chute to the apex of the canopy or to a sleeve or bag. Bungees.  Pack opening bands. Burble.  The turbulent and unstable airflow behind a falling object, such as a skydiver in free fall. Cable ripcord.  A flexible metal cable  3 ⁄32 " diameter made  of 49 strands of stainless steel wire. The cable runs from the  ripcord grip to the locking pins. It is housed in a flexible,  protective tube. Clamp.  A medical hemostat used by riggers for picking  threads or retrieving small objects. Chute. A contraction of the term “parachute,” and used  interchangeably with it. Chuck.  The upper part of the tool used to install fastener or  grommet parts. Chest parachute.  A parachute worn on the wearer’s chest. Chafing strip.  A light piece of webbing positioned between the load bearing webbing and a piece of hardware that acts  as a buffer between the two. CFM.  Cubic feet per minute. A measure of permeability. Certificated.  A personnel parachute holding an FAA  TSO certificate. Also used to refer to other FAA-approved  parachutes, such as Government surplus personnel models, which were manufactured under military contract. Centerline.  Lines that run from the risers to the apex of a  canopy and are used to pull the apex down, such as on a  Para Commander. Center pull.  A ripcord design for chest parachutes. Canopy releases.  Devices that allow immediate release of  the parachute canopy. They disconnect the harness main lift  webs from the risers. Canopy relative work (CRW).  A skydiving discipline where  the parachutists fly their open canopies in a formation formed  by grasping the canopies or lines using the hands or legs. Canopy fabric.  The fabric used in the fabrication of parachute  canopies. It is lightweight and woven to withstand the impact  of air pressure when the parachute opens. The canopy fabric  is woven from nylon yarns usually in a ripstop weave. Canopy.  The umbrella-like surface of a parachute and its  framework of cords, called suspension lines, from which  the load is suspended. The drag surface of the decelerator. Calendering.  The process where a machine with heated  rollers is used to finish fabric. The heat and pressure process  lowers permeability by forcing the fibers between each other  and flattening them. C  G-2