Dropping Sensation

[rickfri59 0]

There have been a few posts regarding this question and people have offered opinions, some being contrary to others. I can’t find a response to the question from someone who would be considered an “authority” (MD, Physicist, Aero Engineer, etc.) on the subject:

Why is there no feeling of dropping when stepping out of a plane? I get more of a falling sensation jumping into water from 15 feet. I’ve heard the following responses as plausible explanations:

No visual reference of things moving rapidly towards you (i.e ground rush). Yes, I realize the earth is rushing to meet us at 120 mph, but at 14K there’s no ground rush effect (for me).

The plane is already moving us forward at nearly 100 mph, so the downward transition is gradual and pretty much imperceptible.

Brain is so overwhelmed by everything else going on that a falling sensation is least important sensation to be generating.

Also, I’ve heard that when jumping from Helo or Balloon the only sensation of speed or falling is the rapid increase of wind noise.

[diablopilot 2]

AFAIK the "falling" sensation is due to acceleration. In stepping out of a plane ther is very little, just a change in direction.

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You're not as good as you think you are. Seriously.

[CanuckInUSA 0]

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The plane is already moving us forward at nearly 100 mph, so the downward transition is gradual and pretty much imperceptible.

This is the biggest reasons why we as skydivers don't get that falling feeling.

Plus, I had a very interesting experience last Sunday while doing a hop n' pop using a demo PD143R canopy. You see the flaps on our King Air airplane experienced some issues (the flaps were temporarily stuck in a down deployed position) on an earlier load and after apparently fixing the problem we were airborne again. But the pilot didn't want to slow the airplane down for the hop n' pop skydivers (just in case the flaps got stuck again with a plane full of skydivers). So jump run for the hop n' pop skydivers was somewhere in the 150 knots range and I actually had to wait for myself to slow down after jumping before I deployed this demo reserve canopy (packed as a main). All I can say is that, it's a neat feeling to wait for yourself to slow down in the air. Oh and my demo reserve opening was terminal and while it didn't slam me, it was abrupt.

Try not to worry about the things you have no control over

[billvon 2,435]

You sense total acceleration. When you let go of an airplane, you are exchanging gravity (32 fps^2) for drag (around 20fps^2 on exit) of acceleration. The only time you don't get this is on helicopter, balloon and BASE jumps, since you don't have much drag to cause that acceleration.

[StearmanR985 0]

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But the pilot didn't want to slow the airplane down for the hop n' pop skydivers (just in case the flaps got stuck again with a plane full of skydivers).

You mean your pilot will normally slow down for you? They don't slow down the Beech 99 over here for us period. I was told, " At 3k GTF out and stay down so ya don't hit your head on the tail and ruin the ride for everyone else!" But talk about a cheap thrill!

Jeff

[The111 1]

As a sidenote, even if you exit the plane at an airspeed exactly equal to your freefall terminal, you will still experience acceleration on the "hill", due to the change in direction of your velocity. Your acceleration is toward the center of the "hill", but this is a much smaller acceleration than you would experience with a still air exit, so for the most part it's undetectable, but sometimes I think I can feel it...

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[Nightingale 0]

there's no dropping sensation because you reach terminal velocity very quickly. What you think of as a dropping sensation is acceleration combined with visual cues that let your brain know you're falling.

[LawnDart21 0]

The only "dropping" sensation that I have experienced in this sport is "dropping" all my cash into the manifest cash drawer each weekend.......

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My other ride is a RESERVE.

[StearmanR985 0]

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The only "dropping" sensation that I have experienced in this sport is "dropping" all my cash into the manifest cash drawer each weekend.......

ROFLMAO I know the feeling.....

[Jumpmunki 0]

does this tye in with why blood doesn't rush to your head when your head down? ...

[LawnDart21 0]

I overheard this at a boogie last year:
Jumper #1: "why doesn't blood rush to my head when I'm head down? ..."
Jumper #2: "Cause you can't fly head down.....your on your back........"
Jumper #1: "Oh, that makes sense."
Jumper #2: "Glad I could clear that up for you."

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My other ride is a RESERVE.

[FrogNog 1]

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does this tye in with why blood doesn't rush to your head when your head down? ...

The blood should rush to your head when you are head-down at any steady velocity. I reckon you don't notice it doing so because you're amped.

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Pull.

[FrogNog 1]

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The only "dropping" sensation that I have experienced in this sport is "dropping" all my cash into the manifest cash drawer each weekend.......

I get a "dropping" sensation a lot in the plane when the air is chunky. I haven't hit my head yet, but I have been prompted to put my hands up more than once.

I used to be so sensitive to it that when the pilot set the flaps back to 0 on climbout, I would pucker. It rapidly became normal, of course. Until a different pilot pushed in on the yoke a bit while setting the flaps to 0. again!

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Pull.

[pajarito 0]

I think the reason you don't feel the same falling sensation like you do jumping off a 15ft diving board is due to the fact that there is no anticipation of impact. You're up too high. If you jump off the top of your house, like I used to as a kid (I know...I know...Darwin), you quickly anticipate the impact with your legs. Same with the water when you fall from the diving board. I would suspect, even though I've never done one, that a bungie jump would also give you the falling sensation. You know you're really not going to impact but your body instincts tell you that you might even though you're ignoring them. Therefore, "your stomach goes into your throat." That's my guess.

[firstime 0]

You have nothing around you to gauge it with.
When on a motorcycle you see the trees wizzing past
If there were stationary objects in freefall then you
would really get that falling sensation. I only get it
if I go low.

[Jumpmunki 0]

hehe good one about the not flying hd thing, sound like summit one of the peterlee lot would come up with heh

i think it's because your whole body (blood included) is moving, where as when you stand on your head on the ground your blood moves and body don't
same in a swimming pool till you put your hands on the bottom then it goes to your head heh.

[skytash 0]

the only time I've had a dropping sensation in skydiving was on a helicopter jump. This points in the direction of lack of acceleration being the main reason for not getting it when jumping from a plane. There is only a change of direction of the speed into the relative wind.

Reaching terminal velocity too quickly by jumping from a plane would not explain why I got this when jumping a helicopter.

tash

Don't ever save anything for a special occasion. Being alive is a special occasion. Avril Sloe

[USPA 0]

No this is wrong, the blood doesn't rush to your head because your body is going at the same speed as your blood. During a head-stand on the floor, your body is still, but your blood is moving, in Freefall they are both moving driven by the same force...

Another way to look at it, is that you are weightless during Freefall, and so is your blood.

The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die...

[billvon 2,435]

>No this is wrong, the blood doesn't rush to your head because your
>body is going at the same speed as your blood.

What?? Whether you are standing still or moving, your body goes about the same speed as your blood. (Does your blood care whether you're sitting in a couch, or sitting in a chair on an airliner going 500mph?)

>During a head-stand on the floor, your body is still, but your blood is
>moving, in Freefall they are both moving driven by the same force...

There's exactly the same force on you at terminal velocity as when you're standing on the earth - an acceleration of 32fps^2. The only time this isn't true is when you first get out of the plane and haven't reached terminal yet. (And of course when you open your parachute.)

When you are head down, blood pools in your head. It doesn't do it as much as when you're standing on your head because a) you're not straining when you're head down as you are when you're standing on your head and b) your body is being supported by air against all its surfaces, and this has a smiliar effect to the bouyant effect that scuba divers feel. (Scuba divers don't feel blood rush to their heads when they are head down because the pressure on their heads is higher than the pressure on their feet, and this keeps blood pressure requirements low.)

[USPA 0]

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>No this is wrong, the blood doesn't rush to your head because your
>body is going at the same speed as your blood.

What?? Whether you are standing still or moving, your body goes about the same speed as your blood. (Does your blood care whether you're sitting in a couch, or sitting in a chair on an airliner going 500mph?)

Ok, over simplification, added by language barrier. Only intended for laymen.

Straining does the oposite, tensioning your muscles keeps blood flowing in your veins, increased heart beat in your ateries. There is a gigantic difference in force on a body in freefall than a body on the ground. In dutch it's called Normaalkracht (Fn) or the force that the ground acts on your body, is does not act this force on your blood directly.

The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die...

[Jumpmunki 0]

what have i started

[billvon 2,435]

>There is a gigantic difference in force on a body in freefall than a
> body on the ground. In dutch it's called Normaalkracht (Fn) or the
> force that the ground acts on your body, is does not act this force on
> your blood directly.

"Normal force" is basically the force that "pushes back" against your body. On the ground it's, well, the ground, in the air it's drag from the air. Your blood doesn't really notice much difference though.

Here's a thought experiment. Get a clear skyball; put enough water in it so it falls at terminal. Take a picture of what the water inside does on the ground. Now jump with it and wait until you reach terminal; take a picture of it again. Then let it go and take a third picture. Afterwards you'll notice that all the pictures are the same - the water is sitting happily on the bottom of the ball as if it was sitting on the ground. There's a difference in the forces the ball feels (i.e. on the ground it's supported at one location, in the air the support is spread out) but the water on the inside can't tell the difference.

[freeflynick 0]

If you are talking about the "dropping" sensation you get when you are on, for example, a rollercoaster, when your stomach seems to lift, that feeling is caused by a negative G force. When you jump from a plane, you are just experiencing 1G, the same as you experience all the time not spent on rollercoasters! Like has been mentioned, you will experience some accelerations, but they are small and generally less than 1G (as gravity is your driving force).
That's my take on it, and the wuffos I tell it to seem to accept it!!
15 mins to weekend, and counting....
CHEERS!!

Hobbes: "How come we play 'War' and not 'Peace'?"
Calvin: "Too few role models."

[Andrewwhyte 1]

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You mean your pilot will normally slow down for you? They don't slow down the Beech 99 over here for us period. I was told, " At 3k GTF out and stay down so ya don't hit your head on the tail and ruin the ride for everyone else!"

If we are getting out at 3k the pilot will slow down to 80mph for us. That's because the only passes at that altitude are in Cessnas. Bill must be getting soft in his old age doing more than one pass on a load.

[pccoder 0]

I agree, I believe that is exactly it.

PcCoder.net