*


All times are UTC + 1 hour



Post new topic Reply to topic
 [ 40 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 12:23 am 
Offline
Frequent Poster
User avatar

Joined: Tue Jul 15, 2008 1:40 pm
Posts: 204
Ok, I just read the report and it says the rider just pushed the bar out.
Now Rick, why are you so perplexed that the kite didn't "depower"??


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 12:33 am 
Offline
Very Frequent Poster

Joined: Sun Jul 13, 2008 9:49 am
Posts: 1126
Location: shallow sea
lobo: may be it's because it is no difference if you try to depower your kite if wind is blowing right from under your kite. at apr. 90 degrees angle?

Rick: suppose you are lofted high, what is the best thing you do?

-let bar go and hope to glide down to the grownd
-try to steer your way to the safety (eg water) not powering the kite
-power the kite and try to glide as long as possible

are those scenarios depends on which type of kites you are flying?


Last edited by eree on Sat Jul 18, 2009 12:34 am, edited 1 time in total.

Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 12:33 am 
Offline
Very Frequent Poster
User avatar

Joined: Mon Feb 11, 2002 1:00 am
Posts: 8254
Location: Florida
Excellent analysis and commentary Craz Z, keep it coming. I've learned a lot more about kiting phenomena considering hang gliding than I ever derived from windsurfing. I think glider pilots have a lot to offer kiting in general, have for years too.

I have a problem, lack of weather hazard awareness, appreciation and avoidance understanding out there. This despite dozens of dead, threatened access and hundreds of articles and threads, for over seven years. The Industry is largely indifferent, instructors as a generality not that sensitive to the topic. Some seem to lack much understanding of it themselves. There seems to be a growing perception of "wind immunity" conveyed by flat kites. People worry more about getting eaten alive by sharks than a dumb squall, hell you can deal with that. Nothing further from reality. Sorry about the thread title, I'm still getting over a bad cold, still a bit thick in the head. At the same time, the highest lofting I've ever heard of was 325 ft. above the ground and about 1850 ft. horizontally. Why would anyone logically conclude it was 1100 ft. particularly given the detailed figure as the first thing in the post?


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 12:45 am 
Offline
Very Frequent Poster
User avatar

Joined: Mon Feb 11, 2002 1:00 am
Posts: 8254
Location: Florida
Good question Erre. The only time I had a spectacular lofting, I just stayed the course and slammed into a house. Thank God for 60 ft. of sea grape trees to smash through along the way to reduce the force of the impact, unintentionally.

They say to first and always fly the plane, or maintain control of your aircraft through the immediate situation. So, I say "fly the kite" as stably and level as you can. As quickly as you can assess your situation and options. Is there something soft to crash into like water, big hedge, even a pine tree within glide radius, if so try steering for it. (WHAT IS your estimate of the glide radius of a 12 or 14 m flat kite trimmed for distance anyway?). Are you still climbing, does the rate of climb diminish by gently pushing the bar out to depower the kite? Avoid turning the kite off in one direction or the other by unequal control inputs, make small sequential inputs if you can to gradually change heading.

In the current case, by depowering the kite by pushing out the bar, Dale dropped altitude and sped up considerably. This accomplished several things. It diminished the likelihood of his overflying into the fence, his primary threat under consideration along with getting him lower to the surface. It also inadvertently reduced his angle of impact which along with the added speed allowed him to "scale" into extremely shallow water without impacting the bottom. This wasn't planned but it still saved his bacon. If the tide had been different severe injury might have still happened. If he oversteered, he easily could have ended up in the parking lot of simply overflying into the fence. Despite the trauma of the lofting and high speed impact, he maintained sufficient presence of mind to release the kite. Often enough, there is one initially impact followed by several more because the kite is still flying but out of control. Be ready to Emergency Depower your kite by best means at the first reasonably safe opportunity. This is usually well before the lofting! Good fortune and keeping his head had a big role in how things worked out.

Going out rigged too big contributed to the lofting in large measure. I have never heard of such a spectacular lofting before in only 30 mph. The newer flat kites have great glide characteristics, that can turn against you if you set yourself up. The beach in that area is pretty flat and yet there was some form of uplift component, perhaps there always is at the water land interface, stagnacy zones and such in addition to what vertically deflecting surfaces may be present. Whatever caused it there was a major vertical component in this case.


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 1:36 am 
Offline
Frequent Poster
User avatar

Joined: Tue Jul 15, 2008 1:40 pm
Posts: 204
eree wrote:
lobo: may be it's because it is no difference if you try to depower your kite if wind is blowing right from under your kite. at apr. 90 degrees angle?


It's sort of obvious, isn't it? That's why I don't understand all the fuss about it....




eree wrote:
Rick: suppose you are lofted high, what is the best thing you do?

-let bar go and hope to glide down to the grownd
-try to steer your way to the safety (eg water) not powering the kite
-power the kite and try to glide as long as possible

are those scenarios depends on which type of kites you are flying?


To idealize how to come down after lofting seems a bit utopic, since you're assuming that the atmosphere suddenly changed from chaos to steady-state.

The point that should be stressed is that the kite must be flagged as soon as possible.


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 1:58 am 
Offline
Very Frequent Poster
User avatar

Joined: Mon Feb 11, 2002 1:00 am
Posts: 8254
Location: Florida
Haven't talked about this in years, flat kites seem to have greater capacity than traditional C kites for this by far. What about "flaring" your kite before impact as most aircraft do before landing? To avoid parachuting up on flaring you usually want to burn off enough speed first. Not sure we'll always have that option. Still, it could reduce the force of impact on landing. Input?


To idealize how to come down after lofting seems a bit utopic,.


Agreed. Yet, there have been some common factors in the few spectacular loftings that come to mind that were survived. Some of the survival factors but not all, in Dale's lofting were fairly random as highlighted. The goal needs to avoid the lofting in the first place. That has been the point for seven years. People will ask, what if, so it bears some discussion.


The point that should be stressed is that the kite must be flagged as soon as possible.


Flat kites have substantially reduced impact trauma over traditional C kites at last check. If they are used under reasonable conditions that benefit should continue to be realized. Problem is it seems some people have gotten it into their heads they need to be less wary of weather hazards. The flat kites I am familiar are a lot more rigid than traditional C kites. As long as the reride or O'shit system worked, traditional C kites would flag fairly well although remain flying at times. Given the flat kites are more rigid, they don't "flag" as well necessarily. They do depower better,that is faster, easier and more completely, within limits, allowing for proper functioning. In this case, Dale needed to Emergency Depower his kite before the wind struck or at least depower it somewhat by pushing the bar out. He didn't do either and was lofted into a situation which temporarily disable the depowering. At that point, he might have ended up in the road even if it had worked 25 ft. up and climbing, still not good.

Is "flagging" a flat kite in the fashion of a traditional C kite advisable? Given tendency to relaunch, spin at times due to more rigidity and bridling, tangle bridles, wingtips, perhaps not. The IDS presents a new approach and may in fact "flag" in a fashion. I've asked many manufacturers about this since 2005 for recommended approaches. The best concept that has come forward for evaluation so far is to bring the kite down side wind window, depower enough to keep a wingtip near the surface, some say to disconnect your kite leash, depower more by pushing the bar out further if necessary but avoid having the kite totally depower and fall over. Finally, be ready to set the lot free if it relaunches and starts spinning. I know some use this approach but not all. There should be a good consensus on what to do, particularly with whatever flat kite you happen to be using.


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 2:12 am 
Offline
Very Frequent Poster

Joined: Sun Jul 13, 2008 9:49 am
Posts: 1126
Location: shallow sea
eree wrote:
do you have any information about possibilities of preventing of fatal accidents caused by rather horizontal lofting (eg kevin of florida case) by driving the kite intentionally in the ground/water immediately after the sudden squall?
is it better to drive your kite (while you can) in the ground risking heavy contusions or better try stay aloft as long as possible?


thats what i am asking for... is that possible?

not if i could long glide to the safety...

lobodomar wrote:
To idealize how to come down after lofting seems a bit utopic, since you're assuming that the atmosphere suddenly changed from chaos to steady-state.

The point that should be stressed is that the kite must be flagged as soon as possible.


well if you did not managed to kill the kite so far (for whatever reasons) you better try to do something when you are already aloft!


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 6:27 am 
Offline
Very Frequent Poster

Joined: Thu Jun 05, 2003 3:37 am
Posts: 2375
Clearly once you are up high you better become a pilot fast and manage a smooth landing.

There are few solutions that will save you from that situation:
1. Know what the heck is hapening and come in before you risk disaster.
2. ditch the kite before you are lofted.
2. put the kite in the water and make sure it stays there.

**none of this has anything to do with what brand of kite or style of kite,
except #3:
If it's any kite that "auto-relaunches," or "auto-taxis" to be ready for relaunch,
you are not likely to get it to stick to the water without risking uncontrolled relaunch.

Any fool that trusts his depower throw to make him safe, on any bow, hybrid or C, is begging for a lofting. Even if it is the latest greatest contraption bridle, it don't mean &@#% when you are connected to a big kite in a squall. If you have some IDS, PMS, UFO, or ESP gimmick that is great when you go out and it's 27 instead of 19 knots, but it doesn't mean a damn thing in a storm.

Here's a picture from last weekend; it went from 15 to 70 knots in a couple of minutes, up in VA. Worth noting is a weather sensor 1 mile away recorded a peak of only 27 knots.
Clearly the time averaging does not help in retrospective analysis of squall lines and microbursts!
For reference, the water within visibility is 2-6 feet deep and the waves developed in 5 minutes over a fetch of about 1/2 mile. The picture is when it was averaging 50+, a couple minutes AFTER the leading edge and peak winds of the squall. 5 minutes earlier it was clear and 15 knots.
Attachment:
DSC01500.JPG
DSC01500.JPG [ 1.6 MIB | Viewed 437 times ]
Too bad I couldn't get the camera out in time to catch the neighbor's canoe blowing through the yard 4 feet off the ground. That was something to see, like a cruise missile. Passing on the chance for a quick session was a decision I can live with.

Thanks for the post on the lofting, but IMHO talking about C vs. bow or IDS vs. whatever else in this context is like talking "duck and cover" drills for a nuke -it misses the point entirely.
The idea of keeping one wingtip in the water in a storm is idiotic -where is the rest of the kite in that case?
Exposed to the 60+ wind that will kill you, that's where!
Not good.
When the heavy stuff comes down, the kite must be ditched or at least flagged on one line with a lot of fervent prayer going on, and if it has a bridle, that is not likely to be at all helpful.


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 3:24 pm 
Offline
Very Frequent Poster
User avatar

Joined: Mon Nov 12, 2001 1:00 am
Posts: 1471
Location: Maryland USA
Craz Z ... we 'kitesurfers' do not associate Montana with Hood River, OBX, Crissy Field, etc... but, I wish to second Rick's welcome of your inputs. Extra, good brain cells always help us less exposed.

The turbulence - rotor - in the boundary layer outside an updraft reminds me of the backwash kayakers fear on the downside of dams. I guess we are all playing within the laws of fluid dynamics, eh? (I had to look it up...) Cheers.

Jim


Top
Profile
 Post subject: Re: Lofted 1100 ft. By Squall And Survived
PostPosted: Sat Jul 18, 2009 6:06 pm 
Offline
Medium Poster

Joined: Mon Feb 10, 2003 4:51 am
Posts: 95
Location: Nantucket, Usa
Rick,

I have come to appreciate greatly your efforts concerning the safety of kiteboarding.

I have personally seen one squall lofting to about 30 ft and the qr worked with no more than a bruise
for it.
The most violent comparison in everyday kiting are megaloops. We use the kite as a brake and get
that moment of no external force or forces are balanced - no acceleration - when the kite is flying back up. Sometimes a second loop or downloop is used to gain speed and bring the kite back around. Makes me wonder what the apparent wind speed is through megaloops or just high loops.

I have no clue but it would be ironic if the most violent kiting move could be used to decelerate and reduce height.

Thanks for your good work
Acker :o


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic
 [ 40 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC + 1 hour


Who is online

Users browsing this forum: Bing [Bot], EastCC, g00se, Google [Bot], joe_mgh, OzBungy and 13 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group