How directional can you be when in freefall?

If you fell out of a plane, for example, but as you were falling you saw a body of water below but it’s not directly below you. It’s about 50 feet away from the point directly below you. In order to reach it you’d have to aim for it and move maybe 50 feet in distance across the horizontal.

Is this possible by changing your body shape? If you straighten out your body with your arms by your side, is it possible to change your direction and travel a significant distance (or any distance) or do you just keep falling straight down like a stone whatever body shape you adopt? How far can you travel, if it is possible?

Need answer fast?

Yes, it is called gliding, and skydivers do it all the time. The glide ratio (L/D for “lift over drag”) for an unassited human is somewhere between 1:5 to 1:6; in other words, at terminal speed you can glide about 1 meter laterally for every 5 or 6 meters of drop. With the aid of a wingsuit, glide ratios larger than 1:2 are possible. Transient increases in the glide ratio are possible by flaring or the use of ground effects as can be seen in videos of people flying down into lakes using a wingsuit.

Of course, hangliders and sailplanes can have glide ratios of 30:1 or better, enough that the small amount of lift from thermal uplifts is enought to give positive vertical motion. That can occassionally happen to skydivers as they emerge from an aircraft moving faster than terminal speed but only for a brief instant.

Stranger

It should be said that if you are looking to use this information in an actual falling out of a plane situation, that aiming at water isn’t going to do you any good. You would be much better off aiming at trees, snow-covered hillsides, or haystacks than bodies of water. You may as well aim for a parking lot, as there won’t be much difference between hitting the water or a bunch of concrete.

I was thinking more of falling off a very high cliff. I just thought a plane would give more room for manoeuvre

Whether you can cover the 50 ft. mentioned in the OP also depends on how high the plane is flying. As Stranger said, the 1:5 and 1:6 glide ratios are at terminal speed. It takes several seconds of freefall to achieve that. Skydivers have much less control at sub-terminal speeds.

So if you jump or fall out from 1,000 ft. you won’t have time to do much. If you jump or fall from 3,000 ft. you’ll reach terminal velocity and if you’re an experienced skydiver you could probably cover the 50 feet. An inexperienced person will most likely tumble out of control until impact.

Ok. Thanks to all responders. Looks like it might be worth a try. Next time I find myself in a freefall situation, if I can see a large bouncy castle or trampoline in the vicinity I’ll try and head for that.

Note, too, that when you are gliding in the atmosphere at terminal velocity, you are not actually in freefall (even though skydivers typically refer to it as such). Freefall is a condition where all forces are balanced such that you experience no net acceleration in your reference frame; that is, the acceleration of gravity pulling you down is balanced by the acceleration that your body is undergoing such that the forces balance out…until you hit the ground or deploy a parachute which imposes a thrusting or pulling load upon you with the resulting deceleration impulse. If you are actually in freefall (no external forces or impulses) such as falling on the Moon or another airless world, no amount of flaring out would result in a glide; at most you could just control the rate of rotation, hence why the Lunar Module had no wings or aerosurfaces and had to land purely by rocket thrust.

Stranger

If you can’t find a bouncy castle or a trampoline, look for a large pile of empty cardboard boxes. A skydiver wearing a wingsuit actually survived a jump where he intentionally didn’t open his parachute and landed in a large pile of empty cardboard boxes.

Water is incompressible at high speeds. Depending on the angle you’ll skip.