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Skipping-stone wingsuit lander

Everybody's talkin' at me.
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A wingsuit is a skydiving jumpsuit which is webbed between the legs, and between the arms and torso. It converts the skydiver into a sort of inefficient flying squirrel.

Wingsuits are fast and, overall, have steep glide angles. Normally, therefore, wingsuiters deploy a parachute in order to land.

Recently, though, at least one person has successfully landed a wingsuit (link). This is possible partly because a last-minute flare can trade forward speed for lift, reducing the landing speed. And also because the landing site was a huge tranche of cardboard boxes.

The landing is still fairly sharp, with a forward speed of something like 30-50mph (descent speed is much less, if the flare is timed correctly).

MaxCo. Extreme Sports, therefore, is currently enlisting skydivers to test its skipping-stone wingsuit rig. This rig resembles a regular wingsuit, but includes a gently curved carapace strapped to the chest of the skydiver. With a well-executed and well-timed flare over smooth water, a skilled person can not only survive the landing, but can skim across the water for well over a mile in a series of diminishing bounces.

MaxwellBuchanan, Jun 20 2013

Wingsuit landing http://www.youtube....watch?v=dRB-woVjlFY
[MaxwellBuchanan, Jun 20 2013]

Yves Rossy http://www.youtube....watch?v=h4arnATc04U
Cheating by wearing jet engines. [MaxwellBuchanan, Jun 21 2013]

First confirmed climb in a wingsuit http://www.tonywingsuits.com/
See half way down page, and links therehencefrom. [MaxwellBuchanan, Jun 21 2013]

[link]






       Ouch. I'd rather not.
pashute, Jun 21 2013
  

       Yes and, besides that its dangerous, why is no one experimenting with adding semi-rigid fins to wing suits to give them more conttol/ slow them down? I would like to see a range of solutions between a wing suit and a hang glider.
JesusHChrist, Jun 21 2013
  

       Too much wingage causes problems. It's hard enough climbing out in a wingsuit. You can go from a helicopter or balloon, but that limits your options.   

       I presume you've seen Yves Rossy, the human jetplane? (Link.)
MaxwellBuchanan, Jun 21 2013
  

       Beautiful. Now shouldn't there be something that is half way between those two -- semi rigid, that would allow the flyer to undulate for control and propulsion?
JesusHChrist, Jun 21 2013
  

       Maybe they could experiment with the design under water.
JesusHChrist, Jun 21 2013
  

       //allow the flyer to undulate for control and propulsion?// Rossy steers by body movement - afaik, there are no conventional control surfaces on his wearable jet. But propulsion is a different matter.
MaxwellBuchanan, Jun 21 2013
  

       Then again, the jump partner of Corliss, Dwain Weston, was wearing a wing suit when he hit a bridge at 120 mph.
4and20, Jun 21 2013
  

       //stall speed of a wing suit is in ground effect.//   

       Stall speed may not be relevant. A conventional ram-air canopy will land you at 0mph forward speed (and a very few mph descent rate) if you use it right, even though its best stall speed is something like (guesstimate) 12mph.   

       Likewise, in a wingsuit it should be possible to burn off all forward speed and convert most of it into lift, briefly, which would offset most of the descent speed.   

       In other words, I think it would be possible to land a wing suit more gently than in that first link.   

       However, the big problem is timing. In a flare, your forward and vertical speeds are changing very fast. In fact, given that the flare is gradual, the _rate_ of change in forward and vertical speeds is also changing quickly.   

       This makes it very difficult to flare a wingsuit accurately. If you flare too high, you drop like a fully-stalled brick from your flareout point. If you leave it too low, obviously you will have a lot of forward and descent speed left.   

       With ram air canopies, it's a lot easier because the pre-flare speeds are much lower; thus, you can adjust your flare in realtime with little practice.   

       If you could get the timing perfect, I'm sure a wingsuit landing on grass would be survivable and even walk-away-from-able, though probably not elegant.
MaxwellBuchanan, Jun 21 2013
  

       I don't think wing suits are capable of even a moment of horizontal flight- even at maximum speed a maximum flare would just result in a slightly less steep dive.
Kansan101, Jun 21 2013
  

       That would be quite correct, [kansan101], were it not for the fact that it's fairly clearly wrong, on the grounds of both physics and experience.   

       If you watch the first video, his descent angle for the last ten metres or so is something like 20 degrees; and his rate of fall during that time is about 4m/s (using his body length as a scale bar of 2m, and estimating the height of the box pile from that, and his fall rate from that).   

       4m/s is about 9mph vertical rate. His forward rate is several times that, but clearly he could burn off some more of that forward speed and convert a proportion of it to lift, reducing both forward and descent speeds, if it could be timed perfectly.   

       I'm not claiming that you can attain zero fall rate (though I suspect it might be possible), nor zero forward speed. I'm simply claiming that a wingsuit obeys the same laws of physics as any glider, albeit one with a high drag and low lift. As such, forward speed can be traded for lift.
MaxwellBuchanan, Jun 21 2013
  

       right up to point where the wing stalls... that being said, I eagerly await the Olympic 1000 metre Free-Fall event.
FlyingToaster, Jun 21 2013
  

       //right up to point where the wing stalls// That's what we were discussing a couple of annotations back - do try to keep up. Flareouts in ram-air canopies, if done right, bring the forward speed to zero, and the vertical speed to very nearly zero, simultaneously and a few inches from the ground.
MaxwellBuchanan, Jun 21 2013
  

       Oh, and apparently you can climb in a wingsuit <link>.   

       From the data linked to from that (5th) link, descent rate was zero or negative (ie, climbing) for about 5 seconds, during which forward speed bled off to a minimum of just 2kph.   

       In other words, if he had attained the near- impossible feat of timing that flare to coincide with his arrival at ground level, he could have landed without spilling a glass of wine.   

       Physics. It's really jolly good.
MaxwellBuchanan, Jun 21 2013
  

       // where are you reading the forward speed from//   

       Altitude is the red line, trending down throughout except for the 5 second kink at about 55 seconds into the flight. Axis is on the left in red.   

       Horizontal speed is the dark blue line which dips noticeably at around 55 seconds. Axis is on the right in blue.   

       EDIT - Oh arse and bollocks. The groundspeed curve is indeed cyan, as per caption, and annoyingly not the dark blue curve to match the speed axis. So yes, you're right, lowest groundspeed is about 70kph (45mph).   

       Howevertheless, he does achieve a climb.   

       A 45mph horizontal (ie, low-descent-rate) touchdown would work nicely with a skipping- stone chest-guard.   

       Alternatively, if he strapped a skateboard on his chest he could land comfortably on any long smooth runway.
MaxwellBuchanan, Jun 21 2013
  

       Yeah, but who do we know who is likely to put up prize money for ordinary people to undertake near- impossible feats involving speed and altitude?
MaxwellBuchanan, Jun 21 2013
  

       You want change?
MaxwellBuchanan, Jun 21 2013
  

       Good point. As a statesman, I accept your kind offer.
MaxwellBuchanan, Jun 21 2013
  

       OK, the data does indicate that horizontal flight is briefly possible.   

       Back to the original idea. Stones have the stability to skip because they spin on the vertical axis when thrown. Planes can do it because they are much less dense than a human or rock (floatier) and have great big stabilizing tails. A guy in a wingsuit would really dig into the water before skipping.   

       Your guy in a wingsuit would skip exactly once, I think, and then tumble forward at 75 kph.   

       Maybe if you dropped a small sea anchor on a long bungee?
Kansan101, Jun 22 2013
  

       If he hit the water at a shallow enough angle not to dig in (and there's no reason not to, given that brief horizontal flight is possible as per link), and did so fairly symmetrically, there would be little if any spinning force imparted.   

       Moreover, a short shallow fin on the rearmost part of the carapace would provide yaw stability.
MaxwellBuchanan, Jun 22 2013
  

       Releasing a small drogue chute or a streamer just before the flare could reduce forward speed _and_ stabilize the landing--maybe even enough for the jumper to land on their feet, if they're a really strong sprinter.
Alterother, Jun 22 2013
  

       Might you consider testing it out on cats first?
Grogster, Jun 22 2013
  

       rollerskates.
FlyingToaster, Jun 22 2013
  

       //What is the maximum speed of a high diver anyway? //   

       I think we did this somewhere. Maximum height seems to be about 50m which, ignoring air resistance, gives an impact speed of about 30- 35m/s or 70mph. But then entry is with the body perpendicular.   

       It's clearly possible to land a wingsuit on cardboard boxes. Water would be harder (if you dug in), or softer (if you skimmed), but definitely doable somehow.
MaxwellBuchanan, Jun 22 2013
  

       Dunno about high divers, but the theoretical maximum speed of a _sky_ diver is terminal velocity; at 120 mph, a diver's hands, wrists, arms, and skull would break before the water did, no matter how perfect the form. People who've jumped off of the Golden Gate Bridge have ended up just as jellified as if they'd smacked into a concrete sidewalk.   

       I imagine the same principles apply for near-horizontal water landings as well. I've certainly seen plenty of footage of airplanes making nice gentle glides into water, only to cartwheel, crack up, or simply stop dead on touchdown. There's a good reason that Captain Sully was lauded as a hero; he wasn't the first pilot to attempt a water landing in an airliner, he was the first to (fully) succeed.
Alterother, Jun 22 2013
  

       I think a wingsuit diver carrying a hydrofoil would have better luck than a skipping-stone device, but it would be less interesting to watch (probably).
Alterother, Jun 22 2013
  

       OK, MB, do an experiment. Go buy yourself a turkey, put it in a scaled down wingsuit with breastplate. Make a big redneck slingshot. Shoot it across your local sewage lagoon.   

       I bet you dimes to doughnuts it will tumble as soon as it touches water.
Kansan101, Jun 22 2013
  

       //I bet you dimes to doughnuts//   

       Sadly I had no access to a sewage lagoon (I believe we send it all to Wales), so the Small Boating Lake had to suffice. Initial results: no detectable yaw after the first bounce. Some pitching, but almost certainly exacerbated by the relatively round nature of the bird.   

       Raspberry jam ones, please.
MaxwellBuchanan, Jun 22 2013
  

       About 8ft in the middle, only about a foot at the edges. Depends on how much rain there's been.
MaxwellBuchanan, Jun 22 2013
  

       I'm afraid my usual cinematographer was at a party. I did get the current Artist in Residence to turn up and make a few sketches in realtime, but I'm not sure the results have the clarity you're after. Last time I hire a cubist.
MaxwellBuchanan, Jun 22 2013
  

       A tumble would result. Seriously. Your guy has nothing at all to prevent it. No spin, no tail, nothing.
Kansan101, Jun 23 2013
  
      
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