Bizarre flying experience

[Mikefule]

I have a good quality 11 foot keeled delta.  I have flown it many times in extremely light winds, nursing it up by careful line management.  I have also flown it in strong enough winds that I have struggled to bring it back down.  I thought I was familiar with it in all its many moods.

Today, I was trying to get it to fly in a very fitful teasing breeze.  The wind was so weak that I couldn't be quite sure which way it was coming from.  I threw tufts of grass in the air and they fell vertically.  However, I could see some rustling in the leaves at the top of the nearby trees, so I knew there was something up there if only I could hook it.  I therefore went for a long line launch and after several attempts, the kite started to pull reasonably strongly and I was feeding out line carefully and getting some decent height.

Within a few minutes, I had it a hundred metres or more up and it was flying at a slightly lower angle than usual.  Then suddenly it started to pull and climb, and after a minute or two it was exactly vertically overhead.  It was not in a glide (I've had that before) but it was actually pulling.  I then realised that it had gone slightly beyond directly overhead - it was slightly behind me.  The line was going up in front of me, then curving BACK towards the kite and the kite was still pulling - not hard, but definitely trying to take line and go higher.

For the first time in a long time, I found myself worried about something going dangerously wrong.  I estimate I had 100 - 150 metres of line out, and I was less than that distance from a road in one direction and houses in another direction.  In theory, these were both safely behind me and "up wind" but the kite seemed determined to go that way.  To reduce the risk, I walked steadily away from the hazards.  The kite continued to pull and remained almost exactly overhead, but sometimes changing its direction of heading.

A couple of minutes later, the moment had passed.  The wind had dropped and the line was sagging down to a less spectacular angle.

I have had a kite glide and over-fly before, but this was not gliding it was pulling.

I wondered about thermals, but I was in a grassy field and there were no areas of tarmac, concrete, water, roofs, etc. that might have caused a strong updraft.

Has anyone come across this before?  Any suggestions?  I like to think of myself as an experienced kite flier, but this was outside my experience.

[makatakam]

Two possibilities that I can think of. The first possibility is a thermal that moved horizontally because it could not punch upwards where it originated, but found a weak spot in the "roof" over the field where you were flying and moved briskly upwards.

The second possibility is two winds moving towards each other from opposite directions and going vertical where you were. When either of these occur, there will be no appreciable wind at ground level to as high as maybe hundreds of feet. Even though it's moving up there, at the ground it's a stalemate with no movement.

There is also this thing called a seiche, which generally applies to bodies of water rising at one end and dropping at the other, the vertical displacement being caused by inequalities in atmospheric pressure. If this is combined with either or both of the above conditions it will make the air move in truly mysterious ways.

Either that, or you've got to cut back on what you're smoking. 

[Kansas Flier]

On 5/10/2017 at 3:33 PM, Mikefule said:

Has anyone come across this before?  Any suggestions?

I don't know if I have ever had anything like that happen before, but it sounds familiar.  Treat it like a glider. Any tail that it can lift, might help. Having to turn around because your kite just flew over your head, and you would rather it didn't do that, usually increases the pucker factor.