mixedup 0 #1 July 2, 2011 something I haven't remembered to ask at the dropzone when I was there.... Is there an optimal angle when you jump out of a plane at 14000 to best go into a stable freefall? When we practice we pretty much jump out of the practice area pretty much vertical, noting the wind is horizontal pretty much at that point I guess. Just wondering if, in a perfect world, should you be jumping slightly forward? say at 45 degrees as opposed to 90 degrees? or perhaps it doesn't matter too much?Parachutist Game IOS Android YouT Quote Share this post Link to post Share on other sites
DSE 5 #2 July 2, 2011 you ought to ask an instructor to demonstrate relative wind, the hill, and how your body translates from horizontal to vertical motion. They might even have an artists model or something to help demonstrate this on the ground. To specifically answer your question, you were probably taught to look at the prop on exit? This is *generally* the most stable way to exit, facing the prop and continuing to look at the prop/door. We even have a contest for the military groups we train here; they face the door/prop of the aircraft as they go, salute the door/prop, and see who can hold the salute the longest as they ride the hill. The altitude from which you exit doesn't really play much of a role in the conversation. Grab an instructor next time you're at the DZ. [edit] notice that in this image that the people leaving the aircraft are facing the prop/door/relative wind. Other exit techniques will make themselves known to you as you become more experienced. Quote Share this post Link to post Share on other sites
crotalus01 0 #3 July 3, 2011 Ask your instructors, but once you have 100 jumps or so it wont matter what "angle" you jump out at, you should be used enough to freefall that you will subconsciously adjust your body position so that you are stable regardless (on solos - group exits depend on everyone to do their job and exit correctly). As for me and my house, we will serve the LORD... Quote Share this post Link to post Share on other sites
JohnRich 4 #4 July 4, 2011 Actually, I kind of like the idea of this question. If you jump out head-high standing-up, you're perpendicular to the horizontal wind. But is that really the most stable? I'm wondering, because that also produces the most sudden transition from zero wind inside the plane to 60-80 mph outside. The jumper is immediately blown backward relative to the plane. And perhaps the suddenness of that change is "less stable". On the other hand, if you exit at, say, a 45-degree angle head-high and leaning forward, you're still plenty stable, but the change is not so sudden, as there is less drag and your forward throw lasts a bit longer. So you're controlling the transition from zero speed to air speed at a more gradual rate and over a bit longer time. And perhaps that is "more stable". Obviously, head straight into the wind would be the most gradual deceleration of all. But that wouldn't be stable, as then leaning in any direction would cause an immediate uncontrolled pitch or roll change. But maybe there's a sweet spot somewhere between perpendicular/suddenness and head-first/gradualness. Hmmm, just a thought. I don't know the answer, but I'll help open up the idea for discussion. Then there's the question of what's more stable for a student, versus what's more stable for an experienced jumper. And what type of plane from which the exit is being made. Ah, but let me not complicate things yet... Quote Share this post Link to post Share on other sites
mixedup 0 #5 July 4, 2011 @JohnRich - this is exactly what I was pondering - perhaps a bit of a lean forward (eg 45 degrees) is slightly better then?Parachutist Game IOS Android YouT Quote Share this post Link to post Share on other sites
butlerhr 0 #6 July 5, 2011 It seems to me that stability on exit from the aircraft is more a result of proper presentation to the relative wind and symmetric body position than the direction taken out the door. The proper presentation gets the body oriented correctly, which is always perpendicular to the wind. The symmetric body position does nothing to change that, which is stability. My experience is that less experienced jumpers have difficulty with the symmetric body position because they have not developed the muscle memory of a truly symmetric body. Many students have trouble with just doing nothing [holding the symmetric position] until the airspeed builds and they have more control. DSE's comment about having them hold a salute sounds like an attempt to get them to hold a good body position. I know it is not the answer the OP was looking for, but my experience is that I can go any direction I want from the door and be stable. Don't ask how long that took. The shiny side goes UP Butler Quote Share this post Link to post Share on other sites
JohnMitchell 16 #7 July 6, 2011 Quote@JohnRich - this is exactly what I was pondering - perhaps a bit of a lean forward (eg 45 degrees) is slightly better then? 45 degrees works for most exits in the 80-100 mph range. You're still on AFF and doing poised exits, right? Most poised exits have the torso of the body at approximately the proper angle prior to exit. Just breathe, count, exit and arch please. And have your instructor explain relative wind prior to your dive exits. Quote Share this post Link to post Share on other sites
kallend 2,027 #8 July 6, 2011 Quotesomething I haven't remembered to ask at the dropzone when I was there.... Is there an optimal angle when you jump out of a plane at 14000 to best go into a stable freefall? When we practice we pretty much jump out of the practice area pretty much vertical, noting the wind is horizontal pretty much at that point I guess. Just wondering if, in a perfect world, should you be jumping slightly forward? say at 45 degrees as opposed to 90 degrees? or perhaps it doesn't matter too much? Just make sure you don't hit the tail.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
JohnMitchell 16 #9 July 7, 2011 Quote Just make sure you don't hit the tail. Troublemaker. Now he has something else to worry about. Quote Share this post Link to post Share on other sites
kallend 2,027 #10 July 7, 2011 Quote Quote Just make sure you don't hit the tail. Troublemaker. Now he has something else to worry about. Well, that protractor he's carrying with him could also be a problem.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
NewGuy2005 53 #11 July 7, 2011 Quote Quote Quote Just make sure you don't hit the tail. Troublemaker. Now he has something else to worry about. Well, that protractor he's carrying with him could also be a problem. Don't forget the plumb bob Quote Share this post Link to post Share on other sites
JohnMitchell 16 #12 July 7, 2011 Quote Don't forget the plumb bob I use one of those instead of an audible altimeter. When the string goes slack, I pull. Quote Share this post Link to post Share on other sites
Ron 10 #13 July 7, 2011 Relative wind is all you really need to worry about. This is more a function of the speed of the plane than anything else. Take a C130 with a jump run of 130 knots vs an Otter with a speed of ~70 knots. The C130 you will be flat out vertical, the Otter will be 60* or so..... (wild ass guess). But the ANGLE is not really important. Your BODY POSITION is. If you are neutral, it will not matter how fast the platform is going. You will be in a perfect balance and stay still. If you force an angle, you will move. Moving can be really good (superfloaters, turning points on the hill) but this type of movement is more about your body position than trying to force an angle out the door. So... Long story short... I would not worry about a perfect angle on exit, I would worry about a perfect body position."No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334 Quote Share this post Link to post Share on other sites
popsjumper 2 #14 July 7, 2011 Quote Quote Quote Quote Just make sure you don't hit the tail. Troublemaker. Now he has something else to worry about. Well, that protractor he's carrying with him could also be a problem. Don't forget the plumb bob Who is Bob? That's plumb crazy. FWIW, I teach perpendicular to the wind as being the best opportunity for stable exits for youngsters.My reality and yours are quite different. I think we're all Bozos on this bus. Falcon5232, SCS8170, SCSA353, POPS9398, DS239 Quote Share this post Link to post Share on other sites
