at   inflation,   thus   improving   the   opening characteristics  of  the  canopy. BAND,   RETAINING—A   rubber   band   used to hold folded suspension lines in a container or faked  lines  together. B A R R E L ,    A U T O M A T I C    P U C H U TE RIPCORD   RELEASE—That   part   of   an automatic parachute ripcord release that houses the  cartridge  and  piston  or  spring  and  piston. BARTACK—A  concentrated  series  of  zig-zag stitches   used   to   reinforce   points   of   stress.   A bartack should have 28 stitches per half-inch (per MIL-O-81900AS). BEESWAX—A  wax,  generally  with  paraffin, that is applied cold or melted to thread to prevent raveling or cloth unknotting and to make thread easier to sew. BIAS  CONSTRUCTION—A  type  of  canopy construction in which the canopy cloth is cut and sewn so that the centerline of each gore runs at a 45-degree angle to the warp and filling thread of  the  canopy  cloth. BINDING—A  piece  of  tape  or  fabric  folded over  and  stitched  to  a  raw  edge  of  cloth  to  prevent raveling  or  fraying. BODKIN—A   large-eyed,   blunt   needle instrument for inserting thread, tape, ribbon, or line through a loop, hem, or channel. Used to feed suspension lines through canopy radial seams or to stow suspension line bights in certain parachute container  assemblies. BOLT—A  package  or  roll  of  cloth  of  varying widths.  Also,  a  measuring  term  for  40  yards  of material. BOTTOM,  FALSE—Apiece  of  cloth  sewn  to the  inside  of  a  pack  to  retain  the  frame.  It  also serves  as  a  base  for  attaching  suspension  line hesitater  loops. BRAID—A   narrow   band   of   interlaced strands. BREATHING—The   pulsating   action   of   the parachute  canopy  when  fully  inflated. BUNCHED  STITCHING—Stitches  too  close or  more  stitches  per  inch  than  required. BURL—A  knot  or  lump  in  thread  or  cloth. BURNS,  FRICTION—A  hard  spot  on  the suspension  line  caused  by  two  lines  rubbing together  at  high  speeds,  generally  off-color  and brittle. C—Abbreviation   for   Celsius. CABLE,  ARMING,  AUTOMATIC  PARA- CHUTE  RIPCORD  RELEASE—A  cable  that, when  attached  to  the  ejection  seat,  lap  belt,  or other   designated   point,   arms   the   automatic parachute  ripcord  release  at  seat/man  separation. CABLE,  POWER,  AUTOMATIC  PARA- CHUTE   RIPCORD RELEASE—A cable covered by a housing, which transmits the force from the automatic ripcord release assembly to the ripcord cable. CABLE,  RIPCORD—A  flexible  cable  joining the  locking  pins  and  ripcord  handle. CANOPY—The  main  supporting  surface  of a parachute that, when opened, reduces the rate of  descent.  It  is  usually  made  of  nylon  and includes a framework of cords, called suspension lines,  from  which  the  load  is  suspended. CANOPY,   CONICAL—A   canopy   con- structed  in  the  shape  of  a  cone.  See  also CANOPY. CANOPY,  EXTENDED  SKIRT—A  canopy that has a flat circular center or disk when spread out.  See  also  CANOPY. CANOPY,   FLAT   CIRCULAR—A   canopy that  has  the  shape  of  a  flat  circle  or  disk  when spread  out.  See  also  CANOPY. CANOPY,   GUIDE   SURFACE—A   mush- room-shaped  canopy  in  which  alternate  roof panels  are  extended  to  provide  guide  surfaces.  See also   CANOPY. CANOPY,  HEM-RIGGED—A  canopy  that the  suspension  lines  are  attached  to  the  skirt  hem and do not pass over the drag-producing surface; for example, the 26-foot conical canopy. See also CANOPY. CANOPY,  RIBBON—A  canopy  composed  of concentric   cloth   ribbons,   supported   by   radial ribbons  and  tapes.  See  also  CANOPY. AI-2