Figure 4-56.  Type 1 deployment in a sport piggyback. Chapter Summary This chapter focuses on main parachute packing techniques.  The first rule is that the lines must be straight (no tangles,  also known as “step throughs”). If the lines are straight and  the slider is up (in square parachutes), the parachute will  most likely open. The speed of the opening directly impacts  the comfort or discomfort perceived by the jumper. Opening  speed and orderliness is controlled by attenuation devices  such as the slider, deployment bag, stow bands, or the diaper  on a round parachute. Accoutrements, such as pilot chutes  and bridles, must be checked frequently for wear that could  affect their performance.  Rubber bands should be changed when they begin to exhibit  small holes or ragged edges. Minor maintenance now  prevents hard openings and major failures later. Learn to be  observant of small details about the parachute system even  when packing the main. Virtually every pack job should  be an inspection. It does not have to be as thorough an  inspection as you would perform at the 180-day inspection  and recertification, but the packer should be vigilant for  damage or things that do not look quite right. Compatibility can be complex. When in doubt about  which TSO a component was certified in, and whether it is  compatible with another component in terms of opening force  generated by the canopy versus strength of the harness, do  not hesitate to call the manufacturer for guidance.  One of the most critical things the rigger must observe when  servicing their customers rigs is reserve bag extraction force.  When a customer brings his or her container for inspection and  repack, reserve bag extraction force should be tested with the  container closed. A good rule of thumb is that the extraction  force should be the same as the weight of the bagged canopy.  If excessive forces are encountered, call the manufacturer. 4-17