> Design and Construction > Automatic Activation Devices and Reserve Static Lines > Reserve Static Line Systems

A reserve static line (RSL) system is a backup device for activating the reserve after a cutaway is performed. It usually consists of a line, webbing, or cable, which connects one or both main risers to the reserve handle, housing, or cable. The most common design used today has a ring through which the reserve ripcord cable is routed. The riser end attaches to a ring on the riser(s) with a snap shackle for quick release capability. When the risers are jettisoned, the lanyard pulls the cable, releasing the ripcord pin(s), and activates the reserve. This results in a minimum loss of altitude during the cutaway procedure. The use of an RSL has saved many lives over the years due to low cutaways

Though originally developed in 1964, the RSL concept did not become popular until the advent of student piggyback systems and ram-air canopies. Through the use of an RSL system, the student parachutist need only pull the canopy release handle in the event of a partial malfunction, and the main canopy is cutaway and the reserve activates. In 1990, the Parachute Industry Association urged manufacturers to include RSLs as a standard feature on all harness/container systems. Many did and this resulted in an increase of RSL use for several years

In recent years and with the widespread acceptance of newer types of AADs, many parachutists feel that they no longer need an RSL. In reality, both systems complement each other. The AAD functions if the individual does not activate the main parachute. However, it is altitude and rate of descent (ROD) dependent. Below a certain altitude, if the ROD is not met, the AAD will not function. Consequently, if a cutaway is performed below the activation altitude, it may take some time for the descending parachutist to reach the ROD necessary to initiate activation, thereby necessitating rapid manual activation of the reserve. However, if an RSL is also installed, it would

cause an immediate activation of the reserve as the main parachute disconnects and moves away from the parachutist. In the last few years, as canopy design has resulted in smaller and more sensitive canopies, many parachutists have elected not to use an RSL. The rationale is that in a violently spinning malfunction, which some of these highly loaded canopies are prone to do, it is preferable to cutaway and regain stability prior to pulling the reserve. This reduces the chance of an entanglement with the deploying reserve. While this scenario has happened, it is a rare occurrence. Statistics show that many lives have been saved by using an RSL