Skydive Radio asked a question with why are teams exiting at 10.5K for competition. Any of you history buffs know why this decision was made?
I want to enter my guess, but it's just a guess. I understand that not every plane back in the day could make it much higher than 10,000 feet when full. So was it perhaps to level the playing field between teams at DZs with good planes and the others?
Yep. 4-way comes from the Cessna 182, which held 4 jumpers (no video -- they watched from the ground with giant binoculars). A 182 normally went to 7200 feet; 10,500 was a high jump. Anything higher was really special (e.g. formation loads), and took painfully long to achieve.
10-ways probably come from the size of the Twin Beech.
10-way speed stars were typically made from lower altitudes as the teams became faster and faster. I recall that when 14-18 seconds were the "norm" we would practice from 7,500 feet. I have a bunch of low teens times in my early log books, and we were not even competitive on the national scene.