Kite Flying Straight Up

by Eamon


What is causing my single line, run of the mill, pound shop kite to fly straight up? Not out at any angle, vertical, straight up above my head even at one mile?


Ha ha - my friend, you have found your first BIG thermal! A region of rising air that is slightly warmer than the surrounding air. It starts off as a huge bubble attached to the ground, but then rises right up to cloud base as a column or elongated bubble. All around it, air is slowly drifting downwards, balancing out the volume of rising air. Your kite was stretching the line tight, with the breeze coming from directly below it.

Lots of my Flight Reports document the effect of thermals on my kites. These effects are actually at work nearly every time you go out to fly, but they are not always so obvious as the experience you had. Here's a good one, written after an outing with the Dowel Dopero kite.

Thermals are amazing. As a sailplane pilot in the 1970s, I remember climbing to 10,900 feet above the airfield in a small single-seater. It was a strong thermal, pegging the variometer at 5 m/s (1000 feet per minute straight up) at times. It was a hot day, even by Australian outback standards, but the air was uncomfortably cold up there above 10,000 feet. Technically I should have been on oxygen at that altitude, but I didn't stay long since other people were waiting on the aircraft.

These days I just let my kites do the thermalling :-) Have fun, and also realize that sinking air has the opposite effect - the kite stays low for no apparent reason, before suddenly deciding to return to its normal line angles once again.

Comments for Kite Flying Straight Up

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Feb 28, 2012
Straight Up!
by: Eamon

Yes you're right! ;0) I have thought about this for quite a few days and your point i.e. "Other forms of rising air can exist in mountainous areas too. Flying a kite near the base of a large slope could certainly steepen up its flying angle, with the breeze travelling up the slope".

To be honest I am disappointed. I was hoping by changing the angle of the kite line attached to the bridle ring one could set up any kite to fly vertically.

Thanks again,

Eamon ;0)

Feb 23, 2012
Thermals Over Snow Etc
by: Tim Parish

3 points...

1) All that is required for a thermal to begin to form is a temperature difference. This explains how sailplane pilots can thermal away from a mountainside above the snow-line. A patch of dark forest surrounded by snow-covered areas can still generate a thermal, although I have never personally flown in those conditions. Even a snow covered slope that is right-angles to the sunshine might have warmer air above it than surrounding areas at different angles. I'm sure large birds of prey still find thermals high up in the Alpes. Mind you, they're pretty good at it!

2) Some kites are very efficient, for example, a well-designed Delta. These can fly at 70 degrees or more from the horizontal. That can look pretty close to vertical! On a light enough flying line, they could hold that angle on quite a long length of line.

3) Other forms of rising air can exist in mountainous areas too. Flying a kite near the base of a large slope could certainly steepen up its flying angle, with the breeze travelling up the slope.

Feb 23, 2012
Straight Up
by: Eamon

Great answer thanks! However ;0) none of my other kites fly like this and Ireland is usually freezing cold ruling out thermal activity. This kite flies straight up at 2 feet all the way up to a mile! There would be no thermal activity at two feet? I was thinking maybe the angle of the kite lines connecting to the bridal ring "could make any kite fly straight up"?

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