No more than 1.0 + .1/100 jumps per Brian Germain's Wingloading Never Exceed formula.
In reply to:
is impossible to tell without knowing how good a pilot the guy is.
It's easy to set an upper bound.
Landing parachutes straight into the wind in large flat grassy open spaces is not hard.
It doesn't get difficult until you have to correct problems like making a low 90 degree turn to avoid power lines for a down-wind landing on an asphalt road on the sunset load after cute chicks flashed the pilot for extra altitude, some one in the group got hypoxic and caught their foot on a seatbelt for a long climb out and long spot, and with the low light the power lines went unnoticed until the last second.
When the jumper in question hasn't been making lots of out landings with low turns to avoid obstacles we don't know how they'll do and they shouldn't be jumping a smaller canopy.
When they've consistently been doing that it shows bad judgement and they shouldn't be jumping a smaller parachute.
Following Brian's formula and the down-sizing skill pre-requisites from him and Bill von Novak (land down-wind, cross-wind, with 180 degree flat turns from 100 feet, with post-planeout carving turns, with induced speed, arrest a dive, etc.) gets jumpers to the point that they have the necessary survival skills, are likely to have the muscle memory to avoid over-controlling the canopy, and are likely to be performing at a psychological arousal level where things going wrong doesn't have them panic.
(This post was edited by DrewEckhardt on Feb 3, 2013, 12:05 PM)