Opened in a dust devil

[skymiles 3]

My 10-way team was practicing this past Sunday at Elsinore. On the 3rd jump of the day, we broke off at ~5000 and I tracked over the motocross track and pulled at ~3500 (ProTrack – 2800 deployment). The canopy was almost fully open when it began to buck and shake violently. It felt like it was about to stall and it looked like it was about to collapse. I thought I was experiencing a malfunction and was prepared to cutaway, but I couldn’t see anything wrong except for end cell closure on the left side. Just then the left front corner of the canopy began to fold under when I decided to release the brakes. The canopy surged forward and the left side re-inflated. The canopy was now flying properly but the ride was still extremely bumpy and I felt very heavy in the harness. I looked over my left shoulder to see I had flown out of a dust devil (or from just above it). I also noticed my alti was now reading 4000!

I headed towards the LZ only to see chaos below me. The flags were raging, but all in different directions, and jumpers were landing every which way. I zigzag back and forth, trying to decide on landing direction and location. I set up to land to the east of the main LZ in the student area beside a windsock. As I approached, the windsock swiveled 180 and I was now being pushed towards the industrial buildings with only about 250 feet AGL to spare. I went to half brakes and quickly checked for other canopies around me. Not seeing anyone, I performed a slow flat turn to the right turn until I felt a strong headwind and the canopy slow. I maintained that heading and came in for a soft standup landing just inside the main area. Except for a few bruised egos, everyone on the load landed safely.

Pucker factor on this dive – very high.

I think I handled the situation well. However, I do have mixed feeling about the low slow flat turn on the eastern edge of the main landing area. Normally, I would consider that to be a big no-no because it interferes with the landing pattern. But in this case there was no landing pattern, I was essentially the last down, and I was trying to save my ass. Nonetheless, does that make it right?

Lastly, is it possible to be sucked back up over 1000 feet and can dust devils reach that high? I distinctly remember feeling very heavy in the harness and almost certain my alti read 4000 feet when I first checked after deployment. If true, then I suppose I got spat out the top of a dust devil.

Phil

BTW – Sabre2 150, WL ~1.3

[sweep 0]

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Lastly, is it possible to be sucked back up over 1000 feet and can dust devils reach that high?

I don't know about dust devils, but I was on DZ control one day a while ago when a tandem caught a huge thermal and went from 4000 feet back up to around 6500. (The pilot radioed down to ask me why they had opened so high when he passed them at 6.5 in the descent). They were up there about 20-25 minutes, and when they landed had ice on their packs/gloves.

Needless to say we stood the tandems down for the rest of the day.... Thermals are powerful things if you get caught up in them.

Sweep

----
Yay! I'm now a 200 jump wonder.... Still a know-it-all tho..

[Reginald 0]

Wow, I’m glad it worked out okay. I was visiting Elsinore about a year ago and had a similar but less intense experience. I was in the saddle at about 2,200ish. I had a very unusual opening, in fact I thought I was having a mal. I didn’t see anything wrong but it was the most unusual opening I had to date. I released my breaks and flew out of the turbulence very carefully. I landed that canopy like a scared kitten. I sat down the rest of the day. Several people on the jump reported similar issues on opening. There were a number of dust devils reported in the area after we landed.

I presume a dust devil can’t go that high per se, but I wold guess it could cause some funky air well above it. Scary stuff.

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[Casurf1978 0]

Really glad to hear that you're OK. I jump at snore too and I'm really scared of the DDs. I did some research on them and the dust column rarely exceeds 1KM, but the thermal updraft can reach 3-4KM above the ground. Mind you this paper uses DDs in the Arizona desert. I included a link to the report, it's really really technical but if you scan it it has some useful info. One question, what time did this happen at?

http://aoss.engin.umich.edu/faculty/nrenno/docs/Renno.et.al.JAS.98DD.pdf

[Scrumpot 1]

Only comment I have is that if you are looking down at the main landing area and seeing "landing chaos" & canopies EVERY which way with NO (or even opposing) patterns taking place... LAND IN THE ALTERNATE!

Elsinore has plenty of room OUT and AWAY from the main landing area, that is also free from obstacles, as well as the industrial buildings (etc.). Your chances of rotors off of those would also be lessened accordingly.

Why does everybody, "hell or high water" seem to have an incessant need to land on the grass (read: main landing area) anyway?

If you were last down, and you KNEW that, your "flat turning" in the situation (or braked turning more precisely from the sounds of it) in of itself was just fine though, and obviously much more preferable than toggle-whipping your carcass desparately "into the wind" (more likely into the ground) otherwise.

-Grant

coitus non circum - Moab Stone

[kelpdiver 2]

Grant, the windsock in the student LZ is pretty far away, no?

Two weeks back I was in those funky thermals there and I well might have been climbing at times.

[Scrumpot 1]

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Grant, the windsock in the student LZ is pretty far away, no?

Yes, I believe it is. However, even that said, there are still several other ways to determine wind direction on final, other than just either fixating or "chasing" (or even NEEDING for that matter) the windsock necessarily at all!

If you are choosing an alternate (or even an "out") landing area because of a clearly observed peril taking place in the main landing area ...concern for needing a windsock seems quite minimalized (or should be) in relative comparison too, don't you think? Or maybe it is that I am missing YOUR point here?

coitus non circum - Moab Stone

[kelpdiver 2]

you asked why everyone lands on the grass. I was merely pointing out that he did not.

[Shark 0]

Several people were in the main landing area giving the dust devil signal. Me being one of them. A former student admitted that he "thought" we point in the direction to go.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1698578#1698578

[jas8472 0]

If you were in or very close to a dust devil I would have thought you 4k alti reading might just be a false reading from the low pressure of the dust devil.

[lowie 0]

You may have been in the core of a very big thermal. The thermal core could be only a few metres across - say 10 to 20m and may look like a large dusty. The thermal itself at altitude would be massive. This ties up with all the activity you say on the ground with regards to wind directions. Paragliders can get up to 8 to 10m/s climbs in a strong thermal so I'd have thought a skydive canopy could atleast get 6ms so if you were in it for 20secs you could have climbed 1000ft.

In a paraglider I've managed to thermal to 3500m (11,500ft approx)

[speedy 0]

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Not seeing anyone, I performed a slow flat turn to the right turn until I felt a strong headwind and the canopy slow.

The wind speed you feel does not change depending on whether the canopy is flying into or against the wind.

But the rest of your story was interesting

Dave

Fallschirmsport Marl

[nate_1979 9]

hmm, I know I should know this, .. but, ... what is the dust devil signal?

FGF #???
I miss the sky...
There are 10 types of people in the world... those who understand binary and those who don't.

[maxmadmax 8]

I got slammed by a Dust/Dirt Devil (without the telltale dirt funnel) about 5 years ago.

Opened normally & when I was at about 3-400 feet...I got slammed & run over by something.

Knocked the toggles out of my hands....left side of the canopy folds under. All sorts of bad shit is happening.

Instictively I reach up and grab what I can (rear risers) and start pulling/pumping...shit I am falling FAST!

All of a sudden the main reinflates & I am flying again!

So I swivel my head around and notice that I am power line high on the left...about 40ft.

Land the canopy.....chunk the rig....walk over to the golf pro shop next door & get several beers!

After all it was my first dirt/dust devil slammmmmmm

Don't go away mad....just go away!

[Squeak 17]

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Lastly, is it possible to be sucked back up over 1000 feet and can dust devils reach that high? I distinctly remember feeling very heavy in the harness and almost certain my alti read 4000 feet when I first checked after deployment. If true, then I suppose I got spat out the top of a dust devil.

Phil

BTW – Sabre2 150, WL ~1.3

At the DZ i jumped as a student, there are railway tracks alongside, on nice hot summers days we'd fly over the trackes and get heaps of lift, we could do it quite a few times, it was more fun than what you described

You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
My Life ROCKS!
How's yours doing?

[Shark 0]

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hmm, I know I should know this, .. but, ... what is the dust devil signal?

Arms pointing in the shape of an "L", one towards you, one towards the danger. Go the opposite direction. I believe all the SoCal DZs use the same signal.

[Squeak 17]

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hmm, I know I should know this, .. but, ... what is the dust devil signal?

Arms pointing in the shape of an "L", one towards you, one towards the danger. Go the opposite direction. I believe all the SoCal DZs use the same signal.

Realy, If i was a jumper and saw someone I respect do that, I would make the assumtion that they wanted me to go where they are pointing
In fact when I was on student gera and caught above a tree line on high winds my instructor did just what you described and guided me to a safer place to land.

You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
My Life ROCKS!
How's yours doing?

[Balls 0]

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Arms pointing in the shape of an "L", one towards you, one towards the danger. Go the opposite direction. I believe all the SoCal DZs use the same signal.

So it looks like someone just scored a field goal???????

----------------------------------------
....so that his place shall never be with those cold and timid souls who knew neither victory nor defeat."

[FrogNog 1]

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Not seeing anyone, I performed a slow flat turn to the right turn until I felt a strong headwind and the canopy slow.

The wind speed you feel does not change depending on whether the canopy is flying into or against the wind.

But the rest of your story was interesting

That's only true in stable flight. If the canopy enters a "room" of air moving differently than the one the canopy was flying stably in, the canopy will immediately be at a different airspeed (and possibly direction) than stable flight and will have to adjust. The jumper feels this adjustment the same as a turn, flare, dive, or combination of these but probably knows he/she did not give control input to cause this maneuver. The dissonance could be simply described as "feeling" a wind change and a canopy slow down / speed up. In addition, if the jumper were near the ground, he/she would have an extra frame of reference for actual wind speed values (instead of just relative windspeed values, i.e. "faster" or "slower") and could reasonably describe encountering a "strong headwind."

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Pull.