*Edit to add: Those guys are doing free fall jumps. Didn't do any of those in the military.
For static line jumps the rucksack is attached to quick releases on the harness under the reserve. It's over your thighs basically. Once you descend to the correct height you release the quick release straps which causes the ruck to drop 18 feet or so below the jumper but is still attached by a tether. At night you can often hear your ruck hit about 1 second before you do.
The ruck is rigged in front of the thighs and is released on a 15 foot tether as the jumper approaches landing. The manner in which the ruck is rigged make it difficult to walk and so the jumpers waddle. In the film, the ruck is seen between the legs because of the straddle. They then jump with legs wide to achieve aerodynamic stability.
There is a difference between standard "mass tac"static line jumps and free fall (tis appears to be high altitude/high opening or HAHO). Traditional static line jumpers will keep feet and knees together but freefall need to have a different aerodynamic stability and so go out spread.
Increase the distance between leverage points and the force on the system is going to increase. If your parachute straps have to go over a 24-36" deep backpack the forces that are generated are going to be 3-5x your normal stresses with short straps and tight to the body.
*Edit to add: Those guys are doing free fall jumps. Didn't do any of those in the military.
For static line jumps the rucksack is attached to quick releases on the harness under the reserve. It's over your thighs basically. Once you descend to the correct height you release the quick release straps which causes the ruck to drop 18 feet or so below the jumper but is still attached by a tether. At night you can often hear your ruck hit about 1 second before you do.
For free fall, I don't know if ruck position in front or behind is jumper's preference or weight driven.
The ruck is rigged in front of the thighs and is released on a 15 foot tether as the jumper approaches landing. The manner in which the ruck is rigged make it difficult to walk and so the jumpers waddle. In the film, the ruck is seen between the legs because of the straddle. They then jump with legs wide to achieve aerodynamic stability.
There is a difference between standard "mass tac"static line jumps and free fall (tis appears to be high altitude/high opening or HAHO). Traditional static line jumpers will keep feet and knees together but freefall need to have a different aerodynamic stability and so go out spread.
Can you wear a backpack over your parachute?
Increase the distance between leverage points and the force on the system is going to increase. If your parachute straps have to go over a 24-36" deep backpack the forces that are generated are going to be 3-5x your normal stresses with short straps and tight to the body.
do you know how big their backpacks are? Imagine putting a parachute backback over their stuffed pack. It would not end well.
Sure, once.
https://files.catbox.moe/al3eiu.jpg
For the leg bags in free fall "flight," it's user preference.
They drop the packs on a rope or strap below and before they hit the ground .