Static line

For other meanings of "static line" or "Static Line" see Static line (disambiguation).

Military static line jump, from the rear of a C-130 Hercules

Deployment bag and permanently sewn 15-foot (4.6 m) static line assembly from military field manual for static line parachuting

A static line is a fixed cord attached to a large, stable object. It is used for safety in construction and to open parachutes automatically for paratroopers and novice parachutists.

Use in parachuting

In parachuting, a static line is a cord attached at one end to the aircraft and at the other end to the top of the pilot chute inside the jumper's backpack. The parachutist's fall from the aircraft causes the static line to become taut, then it pulls the pilot chute free of the backpack. The inflation of the small pilot chute in turn causes the main canopy to be pulled out of the backpack. The continued fall of the jumper causes the main parachute lines to extend and become taut, at which point the binding that joins the static line to the pilot chute comes apart from the shock of the jumper's weight, freeing the parachute and its passenger to continue descending freely, no longer connected to the aircraft. The main parachute then inflates, braking the fall. This static line mechanism opens the parachute automatically with no action required by the passenger.

The parachutist must adopt and maintain a suitable body position throughout deployment to minimise the chances of a parachute malfunction. This method of parachute deployment is commonly used in several ways:

• Training student skydivers
• BASE jumping
• Military paratroopers jumping from very low altitudes (400+ feet or 122+ meters)
• Soviet and successor state military standard procedure for all airborne infantry jumps, regardless of altitude

Static line jumping carries risk of injury that, according to one study, doubles when performed in combat.

For training students in civilian operations, modifications to existing static line equipment may be made to simplify operations. One such modification is to attach the deployment bag to the parachute instead of the static line, which also requires some modification to allow the static line to detach, typically a Velcro fastener. This leaves much less material "in the wind" behind the plane after the jumper has left; this isn't a problem for larger cargo aircraft used in military jumping, but presents a major issue for smaller aircraft used in civilian operations. This modification also results in a somewhat slower opening, which softens the opening shock at the cost of altitude, a minor concern for jumpers exiting at 2,800 ft (850 m).

Use in construction

In construction, a static line is a safety measure consisting of a cable race fixed to a roof at intervals to which a safety harness may be tethered.

External links

• What is Static Line Training? from DZsocial.com
• Static Line Monthly publication since 1947 for, by and about paratroopers, glidertroopers, air assault troopers.
• ArmyParatrooper.org Unofficial headquarters of military Paratroopers, past and present.
• The European Military Parachuting Association