Turbulance? on landing - OUCH!

[IsleOfAvalon 0]

Apologies if this is in the wrong place, I’m new to posting & won’t be offended if it gets moved!

Had a bit of a nasty experience on Wednesday, still in a lot of pain & dosed up on codeine so if I seem a little incoherent please forgive me! Just thought I would share my experience so I can hopefully learn from it & will know what to do if the same thing happens again in the future.

I was coming into land after a hop & pop (from 5,000ft), on final approach, flying over the grass landing area. I initiated my flare (slightly early I reckon) so decided to hold it there for a second or two. Looking at the video both toggle inputs were pretty much even but suddenly my canopy dived right & I hit the ground hard, pretty much at the same time as the canopy.

I was doing a 2 day canopy control course so my landings were being filmed & debriefed. Both the course instructor (who has 11,500+ jumps) and the CCI watched the video & reportedly could not put the incident down to pilot error. Apparently they have not seen anything like it before & wondered if it could have been due to turbulence gusting over the concrete road which runs parallel to the landing area. (I had not crossed this at any point below 1000ft though). It was a nil-wind landing & it was unusually hot for UK weather at this time of year! (Could this be a factor?)

I felt slightly relieved that it seemingly didn’t reflect massive error on my part but I am keen to learn as much as I can from the incident, i.e.
1) is there anything I can do to prevent the same thing happening again in the future?
2) is there anything I could have done to prevent the outcome being so painful?

Factors I have considered so far:
- I didn't PLF, should I have done? (would this be possible given that I landed shoulder 1st, legs last?)
- Should I have tried to complete more of a flare?
- It looks like I leant towards the right & looked right once the dive had initiated - did this worsen the problem?

Here is a link to the video (DivX codec required), let me know if it doesn’t work & I will talk nicely to my boyfriend & get him to upload it again!

http://freeside.dcs.hull.ac.uk/~jono/Em-Nasty%20Landing.avi

Any opinions or advice will be gratefully received! (feel free to ask questions if I’ve missed anything!)

JUMP NUMBER: 111
CANOPY: Spectre 190
WINGLOADING: 0.96
WINDS: nil winds

[Katherine 0]

you should upload a photo of your bruise too...

Leeds University Skydiving Club
www.skydiveleeds.co.uk

[DJL 232]

It looks like you may have reached to the right a little but that was after your canopy had already been blown to the right. That's just plain crazy shit. It's as if you ran into propwash from an aircraft's fully revved engines.

"I encourage all awesome dangerous behavior." - Jeffro Fincher

[IsleOfAvalon 0]

Quote

you should upload a photo of your bruise too...

As requested here are a few pics...if anyone's offended by the brusing you can blame Kath, lol!!!

[ccsayre 0]

2 things I noticed on the video. It seems there is a considerable amount of wind,(listening to the audio). Also, take a look at the P/C, it looks like just before the turn the P/C drifts to the left of the main. That may suggest a toggle turn. If there was prop wash or something like that, wouldn't the P/C react the same way as the main? Anyway very happy you were not hurt worse.

Just my observations...your instructors know best.

Luck is Preparation meeting Opportunity

[piisfish 135]

Quote

It was a nil-wind landing & it was unusually hot for UK weather at this time of year! (Could this be a factor?)

wow this is scary. could be you hit some thermal , a burble just leaving or something...

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[billvon 2,406]

We had something happen that looked similar last week at Perris. A dust devil came to the grass area, crossed it (they're invisible over grass) and caught a few people. One guy was turned hard right and ended up sliding 30 feet on his side. Since he was already planing out there was no vertical to deal with so he was fine.

When your canopy is caught by a dust devil there isn't too much you can do to recover 100% - it's a lot more powerful than your inputs will be. About the best you can hope for is to keep the canopy mostly above your head. Use the toggles to make this happen. If it's collapsing, half brakes can help it reinflate. If it's just heading in an odd direction, then full flight will get you out of it sooner - keep flying it, turn it with toggles, but keep the other toggle up. Near the ground flare and PLF as always.

>- I didn't PLF, should I have done? (would this be possible given that I landed shoulder 1st, legs last?)

Whenever anything comes up like that, be prepared to PLF. (In your case it would have been more of a shoulder roll, but the basic preparation - feet and knees together, knees bent, body 'curved' so you can roll.)

>- It looks like I leant towards the right & looked right once the dive had
>initiated - did this worsen the problem?

Yes. The natural tendency is to "put your hand out to break your fall" and this can worsen the problem. Turning the other direction may have kept the canopy over your head a bit more.

[Katherine 0]

Quote

A dust devil came to the grass area, crossed it (they're invisible over grass) and caught a few people.

Whats a dust devil?

Leeds University Skydiving Club
www.skydiveleeds.co.uk

[christelsabine 1]

Can't open the link. Tried with IE and Mozilla Firefox, what is missing here? DivX is installed. Thx for help.

dudeist skydiver # 3105

[dharma1976 0]

at least it was a small dust devil looking action...I heard of a guy in eloy that got picked up and thrown over the packing area (a huge hanger)

you got lucky with just the bruising...

and no not much you can do but pray you will be alright

(not religious in anyway)

Dave

http://www.skyjunky.com

CSpenceFLY - I can't believe the number of people willing to bet their life on someone else doing the right thing.

[IsleOfAvalon 0]

Quote

A dust devil came to the grass area...

I've read a few threads talking about dust devils in the past but don't really know what they are Does anyone have a simple explanation of what they are & what causes them? Also with an awareness of the fact that they are an existing phenomena is there anything you can feature in your flight plan to avoid being effected by them?

Quote

Whenever anything comes up like that, be prepared to PLF. (In your case it would have been more of a shoulder roll, but the basic preparation - feet and knees together, knees bent, body 'curved' so you can roll.)

Everything seemed to happen very quickly; I kinda went into panic mode & wasn't able to maintain my focus on "flying the canopy all the way to the ground" which could have been lethal. I'm dissapointed in myself that I didn't think fast enough to PLF.

I'm wondering if it would be possible to practice adopting the PLF position at altitude? It's just I've remembered to PLF in the past on fast landings but it just seemed that because this landing was so out-of-the-ordinary it was not the 1st thing that came to mind (and I'd like to remedy that)

Could I simulate this situation (at altitude) by turning canopy to the right using toggles then practice the PLF position whilst simultaneously counteracting the canopy dive using opposite toggle input (and not reaching out with my right hand!!!) Would this be a useful exercise or is it complete madness??? (obviously I'd check for traffic & ensure I had enough altitude & all the other necessary checks before carrying it out!!)

Quote

The natural tendency is to "put your hand out to break your fall" and this can worsen the problem. Turning the other direction may have kept the canopy over your head a bit more.

Ironically the jump before this was spent learning how to avoid the tendency to "reach out" to break your fall by practicing at altitude (as part of the canopy control course I was doing). I will definately be putting in a lot more practice of this skill when I'm brave enough to get back in the air (and when it no longer hurts to even breathe dammit!!)

Thanks for all your input so far everyone, it's all been really helpful. I really didn't wanna walk away from this without seeing it as a valuable learning experience.

[IsleOfAvalon 0]

Quote

2 things I noticed on the video. It seems there is a considerable amount of wind,(listening to the audio).

I too was baffled by that because it was definately a nil to very low wind day. I've looked back through other footage from landings on the same lift & the windsock was pretty much hanging vertically! It may be something to do with an over-sensitive mic or due to the positioning of the mic or something, I don't know!!

Quote

If there was prop wash or something like that, wouldn't the P/C react the same way as the main?

You're right, it definately wasn't prop wash as the plane was still in the air (going up to 15,000ft whereas I exited at 5,000ft)

Quote

Anyway very happy you were not hurt worse

Thanks dude, the outcome coulda definately been a lot lot worse!

[MF42 0]

A dust devil is a small funnel-shaped vortex that wind can sometimes form. Kind of like a tornado, but much slower and smaller, sometimes only 10 feet across. They're only visible when they pick up dust, hence the name. It would be very unusual to find one in no-wind conditions, or in high winds. They form when gentle winds blow across some object at a certain angle that causes the wind to spin into a vortex. Once the vortex is spinning it's fairly self-sustaining and can travel surprising distances away from the initial object.

When I was a kid I loved running up to a dust devil and tossing in a handful of leaves. It was fun to watch them twirl away into the sky. No fun hitting one under canopy though.

Matt

[wmw999 2,130]

You can practice, and make a PLF position your automatic response to anything uncertain in landings. For that matter, you can come into all landings in something closer to a PLF position, and change to stand it up or run it out if the landing is docile enough.

It does take practice; when things are going bad quickly, there aren't always a lot of brain cells left over to think outside the box, you're too busy reacting to what's happening. If a PLF position is your automatic response, then you can continue to use all your faculties to respond to the situation.

Wendy W.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[darrenspooner 0]

Hey, thanks for being brave enough to post this, complete with video. No authoritative comments other than to say that it looks like a freak unpredictabl gust. If it was a hot daythen thermals and winds can combine to make it totally unpredictable. From seeing the video you didn;t seem to do anything that could cause such a radical shear.

Another way to see that there are uncontrollable and unpredictable variables in this sport

[Rooky 0]

ieks, hope you recover fast
don't be so hard to yourself, because not plf'ing. i'm sure, next time you need it, your instinct motions are more like plf.
although noone wants such a situation, i think you will learn a lot from that (or already learned).

my bet is nasty gust or dust devil , too.

Quote

1) is there anything I can do to prevent the same thing happening again in the future?

as others mentioned already, theres not much you can do to fully recover your canopy from those conditions.

Quote

2) is there anything I could have done to prevent the outcome being so painful?

i think your early flare made the situation worse. not a big deal in no-wind, but here?
something i remember from brian germains article "Collapses and Turbulence" (link still on dz.com main page) is, your best weapon against turbulence is forward speed. right at the moment the gust hits your canopy, your forward speed was nerly zero.
imagine an perfect flare situation. now if the gust had hit you at the same altitude, the effect on the canopy were less critical, because of more forward speed (canopy passes the gust quicker and your toggle inputs have more effect with more forward speed).
if the gust had hit you at the same "nearly zero forward speed" in that perfect flare scenario, than the result would be same as it happend to you, but your fall would have been much lower, because you had reached the ground already (at least with your feet).

just my 2 cents.

oh, and sorry for weird write up, english is not my first language. i hope that makes any sense.

and to all the expierienced guys, please correct me if my thought were totally bullshit!

hope, you will come out of it even stronger
rooky

[crotalus01 0]

had something similar happen to me not too long ago. i was coming in on final and started to flare, pretty much the same thing but not as hard a turn. i caught a thermal updraft with the left side of my canopy that caused a turn as i was flaring. i tried to compensate but ended up eating it. PLF is your best friend in those situations (hell, PLF is MY best friend in most of my "landings" ).
glad you are just bruised up. it looked worse than it turned out.

As for me and my house, we will serve the LORD...

[IsleOfAvalon 0]

Quote

i think your early flare made the situation worse. ..

This is something I am definately planning to work on as soon as I get back in the sky. I'm gutted that my opportunity to benefit from some of the UK's best canopy coaching was called to such an abrupt end! I'll just have to smile sweetly to my instructors to get feedback on my future landings so I can nip this early flare in the bud asap.

Quote

imagine an perfect flare situation. now if the gust had hit you at the same altitude, the effect on the canopy were less critical, because of more forward speed

This seems to make sense to me...can anyone else confirm that this would have been the case?

Quote

oh, and sorry for weird write up, english is not my first language. i hope that makes any sense.

Believe me, your English is a whole lot better than my German

[IsleOfAvalon 0]

Everyday's a school day! Seems the dust-devil theory has hit the nail on the head. I sent a link to this thread to a friend who was on the same lift as me on wednesday...he replied with the following info:

"It must have been a dust devil cos I saw one at the kit up area that morning. It went from the bench at the outside of the creeper pad, to where I was stood at the bottom of the ramp to the day room. Was just like a very tiny twister. Didn't know what it was at the time"

I've naively read threads about dust-devils in the past and assumed it only happens in humid countries, certainly never thought it could happen in the UK! (never was that big on physics!!)

Just goes to show that you should never rule anything out as a possibilty in this sport. Everything that has happened to someone else could just as easily happen to you today, tomorrow or 5 years down the road. Learn as much as you can about as many things as you can & practice them till you can do it in your sleep. One day it might just save your skin.

EDITED TO ADD:

what are the implications of dust-devils then? Should we be staying on the ground on days where they're about?

[strop45 0]

I'm not even a 100 jump wonder (yet) so claim no expertise whatsoever in canopy control, however I have been flying radio control sailplanes for over twenty years and know about thermals (aka dust devils). Thermals are a result of the sun heating the ground/tarseal/roofs etc. This causes hot air which then rises and turns.

Thermals can be very small (say 10 feet/3meters across and 100 feet/30 metres tall) to very large (say 2000 feet/700m across and 3000 feet/1000m tall). They are characterised by warm air moving upwards and spiralling (like the traditional image of a tornado, albeit slower) about a center and air moving downwards just outside the thermal.

When you fly into a thermal the edge of the canopy nearest the centre of the thermal will go up in the warm air, while the other edge will be in sinking (and usually colder) air. This appears to me to be precisely what happened to your canopy.

So what does this mean for skydivers:

1) Be aware of the circumstances which create thermals. Hot sunny days with little or no wind (contrary to an earlier poster, no wind days create more thermal activity and dust devils, they just don't move much) are the days which create the most thermal activity. Thermals are generally present from mid-morning to after sunset.

2)Beware of areas downwind of dark surfaces - the runway, roads, dark roofs, freshly ploughed fields etc.

3) Thermals can be observed in a number of ways - dust, temperature differences (you can often feel the cold/warm air), seagulls, and by the sinking air around them. None of these should make you turn in your landing pattern, but should just make you aware that you may have to aggressively control the canopy to stay straight and level.

4)If you encounter a thermal, it will try to turn you away from its center, your best response is to keep the canopy above you (wings level for a model sailplane) by fighting the thermal induced turn, i.e. try and stay on course. If you get into the middle of a thermal you will be in rising air, i.e. your sink rate will decrease, but be aware that on the other side you will encounter sinking air and you sink rate will rapidly increase.

Again I have no expertise in canopy control and make these comments soley based on years of flying models in and out of thermal activity, however it seems to me that the same general principles apply.

The difference between stupidity and genius is that genius has its limits." -- Albert Einstein

[DSE 3]

There is simply no way to accurately or intelligently predict dust devils. If you have warm and cooler ares, they can immediately kick up with a small gust, or not. Here in the desert, they're very common, and anywhere you've got a superheated area and a cooler area...there they may be. They're invisible over grassy areas. I don't believe there is anything you can do different beyond what you've asked. I showed this to an instructor here who has once been hospitalized from a devil crossing his swoop, and once been seriously face-planted during a "normal" landing. His comment echoed most comments here; you can't stop it or avoid it. His only advice to me was if I see one, try to steer into it if it's at a point that I can see it. Our DZ isn't grass, so it's somewhat easy to spot them with the dust. But in my yard and pasture, you can't see them. They just hit you.
Glad you weren't injured more than the bruises.

http://en.wikipedia.org/wiki/Dust_devil has a picture of one. Bear in mind it only has color in it because it's over a dirt field.

[mdrejhon 8]

http://freeside.dcs.hull.ac.uk/~jono/Em-Nasty%20Landing.avi
Scary video! I've never seen anything like this before. Now I know what a dust devil (if this is one) can potentially do (If this happened at 50 feet altitude rather than 5 feet altitude, you might not be living!)

I have flown through turbulence at 50 feet - that could be a preclude to something worse. Not necessarily, but a thought to ponder... I see that your canopy if hit by "normal-looking" turbulence a few seconds before you suddenly hit the unusual gust. And I heard dust devils are invisible above grass!

In any case, this video should be uploaded to www.skydivingmovies.com - it is very educational on the dangers of turbulence/gusts/dust devils!

[NWFlyer 2]

Quote

you can't stop it or avoid it.

But you can decide to stay on the ground when the weather patterns indicate that they are likely. My last visit to Perris (when I had just around 100 jumps), I watched the locals for guidance. When they started sitting down because the conditions were getting squirrelly, my day was done, too.

I live in a climate where they're pretty unlikely. But when I am a visiting jumper where they're more common, I pay attention to what the locals can tell me about the weather patterns.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[billvon 2,406]

> Does anyone have a simple explanation of what they are & what causes them?

Dennis Pagen has a great description of them in his book Understanding the Sky, but in the meantime:

During the day, the sun heats the ground and that heats the air close to the ground. Hot air normally rises. But when you heat one entire layer of air, it can't all rise or there would be a vacuum under it. So what happens most of the time is that the _really_ hot air (like over a road) rises, and is replaced by cool air (like over a lake or a forest.) That's where you get thermals from, which are large patches of rising air.

If the sun is heating a large area uniformly (like a big field) this can't happen as easily because there's no nearby cooler air. So the air near the ground just gets warmer and warmer. At some point a 'bubble' of hot air pops up and escapes. Once this happens, the hot air near it starts streaming into the same area to escape upwards; the colder air above the bubble falls to the ground to replace the air. Usually the rising air starts to spin, like the water draining out of a tub. That's how a dust devil starts.

On the ground, you will notice this due to the dust it picks up. If it's a grassy field it's harder to see. You may notice a sudden strong wind that changes direction quickly; that's an indication that a dust devil is nearby.

> Also with an awareness of the fact that they are an existing phenomena
>is there anything you can feature in your flight plan to avoid being effected
>by them?

1) Avoid jumping when they are in the area.
2) Watch for them under canopy. You can feel/smell them high up; they're warmer and they smell like the ground (usually more humid.) You can see them from the dust, leaves and bits of trash they pick up with them. If you see them, avoid them and the area downwind of them (they usually move with the wind.)
3) If you do encounter one, fly either full flight (if your canopy is behaving OK) or in half brakes (if your canopy is collapsing.) Correct for any tendency to turn with your brakes.

>I'm dissapointed in myself that I didn't think fast enough to PLF.

Practice on the ground! Find a hanging harness and just practice getting into a PLF position over and over, until it become habit. Practice "flare PLF" over and over until those two are linked. Then you'll have to make a conscious effort to NOT PLF which is how it should be.

[gingerjo 0]

Jesus Em!!!! Ouch is hardly the word!
From the vid it looks like you were very lucky although it probably doesn't feel like it right now
Hope that boyfirend of yours is looking after you and bringing you lots of cups of tea
thanks for posting as i've learnt a few things i didn't know about dust devils etc...like you say, every day is a school day.
and thanks too to billvon for the really clear explanation of dust devils. Is the book you mentioned aimed purely at skydivers or what? I really struggle sometimes with skydiving explanations but i found that one really clear and straightforward and wondered if the rest of his book was just as clear.
hey em...maybe you could buy a couple of copies with AU money? worth looking into if it explains things like that so clearly.
glad you're kind of ok, sending you lots of love and hugs, heal fast chick
sunny blues
mama jo xx