it into the airstream. The pack is held closed by a locking pin  attached to the bridle of the pilot chute. As the pilot chute  inflates, it extracts the pin from the locking loop and pulls  the parachute from the pack. The rest of the opening process  is similar to the spring-loaded pilot chute. This configuration  came into popularity in the mid 1970s and is now the primary  method of deployment in skydiving. Kevlar $^{®}$ tape and have tubular nylon centerlines. Others are  made from Type 4 square weave with a Spectra centerline.  The advantage of the latter is that it can be cut with a hook  knife in the event of an on-person malfunction.  [Figure 2-39] Spring-loaded pilot chutes date from the 1920s. However,  it was not until 1940 that the spiral vane pilot chute was  invented. This design used a spiral spring that is easy to  collapse and pack. The most common type of spiral vane pilot  chute used today is the MA-1 model.  [Figure 2-40A and B] This is used in several military parachute assemblies. In the  early days of skydiving, military pilot chutes, such as the  MA-1 and others were popular. Soon commercial designs  were introduced that improved on the MA-1 with better  launch and drag characteristics. These included the Grabber $^{®}$  and Hot Dog$^{®}$ pilot chutes. Both of these were primarily for  use with main parachutes.  Another method of collapsing the pilot chute is to install a No.  8 grommet in the deployment bag and allow the bag to float  on the bridle. After the canopy deploys, the bag slides up the  bridle, inverts, and covers the pilot chute. This is commonly  called the “poor man’s collapsible pilot chute system.” The  drawback to this design is the high wear on the bridle and  pilot chute mesh. With the advent of the hand deploy pilot chute for the main,  most of the improvement in spring-loaded pilot chute design  has focused on its use in the reserve or emergency parachutes.  This has paralleled the improvements in container design and  the increased use of AADs. Both of these require better pilot  chutes than in the past. Figure 2-39.  Tandem main collapsible bridle. Spring-Loaded Pilot Chutes Pilot Chutes  Hand Deploy Pilot Chutes  One example for reserve use is the  Magnum$^{®}$ pilot chute  designed by National Parachute Industries.  [Figure 2-41] With its unique shape, it provides maximum drag at low  speeds, such as are experienced during cutaways. Its design  has been licensed by other manufacturers for use in their  assemblies. Additional designs include the Vector II reserve  pilot chute and the Stealth pilot chute. The Vector II design is  a “ballute” configuration that eliminates the use of mesh. In  the event of an unstable launch on its side, the mass of fabric  is sufficient to lift the pilot chute and deploy the parachute.  The Stealth pilot chute uses a conventional mesh design but  has a unique spring/cap configuration that allows the pilot  chute to virtually disappear when packed, hence the name.  The MA-1 spring with mesh in place of the vanes, and a  closed canopy instead of the scalloped canopy provides the  best of both worlds: a spring that does not lock up on itself  and high drag without the possibility of snag. A pilot chute is a small parachute that is used to deploy the  main or reserve parachute. In the earliest uses of parachutes,  the parachute was static line deployed. With the advent of  manually operated or “free fall” parachutes, the need for a  pilot chute was quickly recognized.  There are two basic types of pilot chutes. The first is the  spring-loaded design. This uses a collapsible spring, which  is compressed in the parachute container and held closed  with the ripcord. When the ripcord is pulled, the pack opens  and the pilot chute launches into the airstream. The pilot  chute provides drag and pulls the canopy from the pack as  the parachutist or load falls away. During this process, the  pilot chute also provides tension on the lines of the deploying  canopy and helps the opening sequence. Spring-loaded  pilot chutes are used primarily for emergency and reserve  parachutes. In addition, they are used in military free fall and  training systems for the main parachute.  The hand deploy pilot chute was introduced in 1976. There  are two types of hand deploy designs. One is the  throw-out  pilot chute (TOP) configuration. This is the type where  the pilot chute pulls the locking pin located on the bridle.  [Figure 2-42]  The original design had the pilot chute pouch  The second type of pilot chute is the “hand deploy” design.  This type consists of the pilot chute canopy but does not have  a spring to launch it. Instead, the parachutist extracts the  folded pilot chute from a pouch or the container and launches  2-17