Turbulence while flying

[nicknitro71 0]

A funny thing happened to me yesterday.

The uppers were cranking (30Knots) and about 5 Knots on the ground.

I was flying my S3 and at 6K I started flying on a straight line towards the DZ. At 5 K I started wiggling all over the sky and dropped down with all my wings collapsed tumbling and rolling. At 3K I regained control got stable and pulled.

It had never happened to me before. The zippers were fine and nothing was wrong with the suit. The WS jump prior to that one went flawless.

Any ides? That would be a shitty deal in the BASE enviroment!

Memento Audere Semper

903

[KrisFlyZ 0]

That is crazy!! Were you wearing a Neptune or protrack? It would be interesting to see the log.

Kris.

[nicknitro71 0]

Yes I had my Neptune. Tonight I'm gonna download the data and see what's up.

Memento Audere Semper

903

[The111 0]

I don't know how weather and wind work, but if there was a large finite jump of wind across a short distance (wind shear is the term I think), then it is feasible that would mess up your suit's flight/inflation. I've seen similar discussions about canopies encountering wind shear. Basically if you are flying your canopy into a strong headwind which promptly disappears, you are left with much less airspeed than you need for your canopy to fly. It will lose inflation to some degree, you will begin falling downward, the canopy will surge forward and dive to reinflate. Since a wingsuit requires a LOT more control to keep stable than a canopy, it's possible that instead of simply diving and surging, you went massively unstable instead, when presented with much less airspeed than you needed to fly...

So to test my theory, I'm curious, were you flying into the wind (upwind) when this happened? OR... were you flying downwind in the upper winds, but the ground winds and uppers winds were in opposite directions?

www.WingsuitPhotos.com

[nicknitro71 0]

I was flying almost downwind not upwind.

The uppers and ground were from the same direction.

Memento Audere Semper

903

[The111 0]

Hmm. Flying with a strong tailwind, if that wind drops suddenly, you should effectively feel like you ran into a wall of air and you get massive amounts of "flare power". Under a canopy that is fine since you'd much rather have too much lift than not enough. I guess it's possible that with a wingsuit, that much lift could overpower you and cause you to lose stability... but I have no idea what this felt like to you so I don't know if I'm anywhere near the right ballpark. The only time I feel instability is when I fly very near a stall (and I'm still learning a lot about flying), and then I start washing side to side. I wonder if a sudden surge of lift could cause you to come near a stall? But even then I've never totally lost it and tumbled from a stall, I just arch a bit to gain stability again.

I guess the only other possibility is some true "turbulence" which I'll admit I don't fully know what that is, but I'd imagine it's some swirling chaotic air that you don't want to fly through... :)

www.WingsuitPhotos.com

[SBCmac 0]

nicknitro71,

Speaking of it happening in BASE... This happened to me on my last WS BASE jump… I had a clean exit and was about 5 to 6 seconds into my jump… And out of no where I felt turbulence, I was being thrown around and I couldn’t do anything about it. Then all of a sudden, I was thrown on my back. Let me tell you, pretty damn scary when you are over a buttress that you haven’t cleared yet … Anyway, so instead of fighting it, I just went with it and continued the barrel roll and inflated my wings once I completed the rotation. Even after the barrel role, for about a second+ longer, I still had issues with turbulence. Once I passed the buttress I went into clean air and was able to pull a sweet 36 second delay out of my ass … So once on the ground, we witnessed fog go straight up the wall from the buttress… So our conclusion is that there must have been thermals coming off of the buttress and I got caught up in them. The jumper before me felt the same funky air but wasn’t affected as much. Looking back, I think I was affected by the turbulence because I was maxed out and was still sub terminal.

Looking back I had two options… Once I felt turbulence, I should have arched and flew in a dirty body position to prevent the turbulence from having such a great effect on me. The problem with this solution though is that I still have to pass the buttress, so flying dirty may have not been enough to get me over the buttress. Second solution, once I finished the barrel role, I should have deployed my parachute. With this solution, even if I had to fly my canopy in dirty air, it’s better than colliding with the buttress in my wing suit… All in all, experience with flying my wing suit is what saved my ass. I truly believe that when you decided to BASE your wing suit, you better fly it like it’s an extension of you… Again that’s the only thing that saved my ass …


SBCmac

P.S. I’ll try and post the video… The only problem is it’s video from the ground, and when I compress it, it may not come out that well…

[nicknitro71 0]

Looking at the Neptune's data there is an increase in speed from 5400 to pull time. The speed went from the lower 50s to a bit over 100!

I can think of two explanations:

-The drastic change from strong tail wind to weak one stalled the wings without giving time to adjust. I was flying compensating for the big push and when gone the wing pitched up generating a stall although I did not feel it.

-The change in wind speeds also could have be accompanied by a change in direction. The lowers were probably coming more crosswind and this let the right wing go up generating a stall but then again I did not feel being pushed to one side just a sudden drop.

Memento Audere Semper

903

[ImagethisPhoto 0]

As a paraglider pilot I have learned ALOT about weather to fly.
I was also thinking it could be wind shear on the skydive. I'm surprised we havent heard about more of this happening to others.
Was there any signs of a storm front coming,, or going?

WS Base jumping a big walls with tail wind has always made me wonder about rotor. Rotor could easily flip a person over with a WS. A strong thermal could also do this. If one side of your body hits a thermal it can flip you over.

Check out the recent paragliding article that was posted on the home page of DZ.com

Tip: imagine wind is water flowing like a river. In a river the rocks cause a big pour over creating a rapid like a wave. These winds that swirl back are the ones that kill.
Also keep in mind that Canyons can act like venturies, making winds much stronger than predicted.
Moral of the story, high winds, are good days to be grounded...

Hope this helps!

Josh Morell
www.imagethisphoto.com

[vesatoro 0]

SBCmac and nicknitro71: in what kind of "flightmode" were you flying when encountering the problem. Were you flying with lots of forward speed and with an agressive angle of attac aiming for distance, or were you aiming for longest flight time and flying near stall point in a "floaty" position? The difference in flight attitude may mean huge difference in the way the suit responses to turbulence or wind shear. The airspeed may make the difference same way as with canopies and other flying devices.

Vesa
BMCI
#845

"Fear is the path to the Dark side"
(Master Yoda)

[nicknitro71 0]

My vertical descent prior to the incident was in the upper 50s so I was not at the best glide angle. I was flying kinda relaxed: legs straight as usual and my arms and shoulders were not a cupped as you want them to be for best glide. Usually I get in the mid-upper 40s when I try for distance.

The thing is that in less then 1000' I went from the 50s to the 100s the drop was that dramatic and I could feel the accelleration.

Again this is something I did not know it could occur. In the skydiving enviroment it's all good and fun too in a sick way but in BASE it could be fatal.

Memento Audere Semper

903