TM 10-1670-327-23&P
UNIT AND DIRECT SUPPORT MAINTENANCE
MC-6 PERSONNEL PARACHUTE SYSTEM
NSN 1670-01-527-7537
THEORY OF OPERATION
General. The MC-6 Personnel Parachute System is a two part parachute system comprised of both the
MC-6 main parachute and the T-11R parachute.
The MC-6 was developed to satisfy the high priority airdrop requirement to reduce parachutist injuries in
parachuting operations.
In a typical combat mission, troops drop from as low as 500 feet Above Ground Level (AGL), and at
aircraft speeds between 130-150 Knots Indicated Airspeed (KIAS). In this operational profile, rate of
descent is highly critical. The MC-6 main parachute has a rate of decent of between 14.5 and 18.5 ft/sec
depending on the jumper's total weight and drop altitude. This yields a 40% reduction in impact energy
and is expected to reduce landing injuries significantly. Injuries upon landing reduce the combat
effectiveness of the assaulting element and require otherwise combat effective soldiers to assist those
injured.
The MC-6 also incorporates an advanced reserve parachute and harness. The T-11R parachute provides
a rate of decent of 26 feet per second. The T-11R harness reserve attachment points align the parachute
opening forces along the long axis of the jumper's body. The harness incorporates the use of comfort
pads, an integral equipment release, and adjustability for use by a 5th percentile female and 95th
percentile male parachutist.
MC-6 Main Parachute. During use, it is located on the back of the parachutist. Opening of the main
canopy is controlled by its shape. The parachute has a forward speed of 10 knots and can complete a
complete 360 degree turn in 5 seconds.
T-11 Reserve Parachute. T-11R parachute is a chest mounted ripcord center pull reserve parachute. In
an emergency situation, the T-11R may be deployed with either hand under the following conditions:
1. Fully deployed main parachute.
2. Partially deployed main parachute (partial malfunction)
Main Parachute Harness. The main parachute harness is adjustable to fit the parachutist. Changing the
settings on the two adjusters located at the shoulder of the harness accommodates individual chest sizes.
The two main lift web adjustments are to accommodate individual torso length.
Main Parachute Deployment Sequence. Activation begins with the static line connected to the aircraft
and the jumper exiting. The static line tightens as the jumper falls away from the aircraft, pulling the main
container closing pin from the container closing loop. The static line is connected to the deployment bag
and as the jumper continues to fall away from the aircraft, the deployment bag is held by the static line.
Two 80-pound cotton break cords, one on each riser group holding the risers and lines in place, break.
After the suspension lines pay out of the line stow loops, the suspension lines pull out of the deployment
bag closure loops, opening the bag mouth. The parachute skirt with its anti-inversion netting (AIN) is the
first to emerge from the deployment bag. The remainder of the canopy continues to pay out from the
deployment bag as the jumper falls away. As the last bit of canopy (the apex) deploys from the bag, a
final double 80-pound cotton tie breaks, freeing the parachute from the deployment bag. As the parachute
system reaches full elongation downstream, the canopy begins to inflate. During the initial stages of
inflation, control line movement is limited by the eight control line limiters. Once completely inflated, the
control line limiters are slack, the extended gores are fully inflated, and the control lines are free and clear.
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