RW and Canopy Performance

In the mid 70's, when the first ramair parachutes were used, many people held the belief that RW and ramairs do not mix. The philosophy was that the ramair had a much greater forward speed on opening than conventional or even high performance rounds. This performance feature posed a collision hazard to others.

Rounds were in the range of 5-10 mph and ramair were around 10-20 mph.

There were other factors against using ramairs on RW jumps. Jumpers many times did not have complete control of a ramair on opening. The ramair could spin, open off heading, snivel or have end cell closure. All of these minor problems meant that a jumper under a ramair could collide with other jumpers becasue he did not have directional control of his parachute.

Possible plans of having the ramair jumper open higher or lower than the other jumpers did not gain acceptance. If ramair jumpers opened above the round jumpers, the snivelling ramair openings would place the round and ramair jumpers at about the same altitude when both canopies opened. If the ramair jumper opened below the round jumpers, the opening altitude for the ramair jumper would be below 2000 feet. Asking the round jumpers to open higher than 2000 feet was not acceptable.

Part of the horizontal and vertical separtion problem was because many jumpers of those days used belly mounted reserves. Tracking to gain horizontal separation was done, but certainly was not producing sufficient separation.

The camp of RW and ramair do mix blamed collisions and near collisions on the round jumper. The round parachute jumper apparently became complacent about tracking, over confident in their skills and careless about waveoffs.

The ramair jumpers promoted the idea that the best way to avoid canopy collisions at opening altitudes is to make sure everyone tracks far enough. In others words, the jumper provides the collision avoidance safety margin, not the type of parachute.

Today, most jumpers have ramairs that are also subject to off heading, line twists or snivelling openings. Still the best way to reduce the chance of a canopy collision is to track far enough from other jumpers before opening. Tracking is much easier to do today with the standard piggy back rig.