If not aided by leeside uplift wave like above, another possible lift factor is shown below. This is the classic sea breeze front that gliders ride at certain times just southwest of SF. Even though slightly off-lee-shore in the kiters case, the cold sea air could be converging against remains of hot air swept off the city:
What are the physics of a "helicopter loop"? There is no free lunch of energy, so it must milk lift at some high cost (of drag, or arm effort?).
I have not heard the expression before - but am not in doubt at all.
It is when the kite is looped above your head, instead of going very low.
Maybe not straight overhead - but kite up high, so the power generates upwards lift and not horisontal speed.
But you are right - there is no "free energy" no.
So you cant extend the lift this way alone. The energy put into it by "arm" force is so small - can not contribute here at all really.
What is it all about then ? When speaking in general terms that kitelooping can sometimes extend the jump ?
Well, dont think anyone can answer this totally specific - but I have some input:
A kite flying at higher speed gives more lift/power - we all know !
So many think, that this must mean that you'll get more lift when looping the kite ? Wrong
A "stationary" kite - which is when you are standing on the ground og bodydragging in the water - is a complete different matter than a kitesurfer in the air
When you are having a fixed point on the ground (bodydragging is to some extent a "bit" fixed - because of the drag in the water) - a kite can generate loads of power when sweeping around fast in the powerzone.
This is to a major extent because you have a bigger "swept area" and uses the power of a bigger wind area.
When in the air - none of this exists
You could say - take a paraglider f.ex (or any glider).
If a paraglider rides straight out, it will no doubt at all have the lowest sink rate (= max hangtime in a jump)
If circling (looping the kite) the sink rate will increase dramatically with narrow turns.
Simple physics and also practical experiences.
Okay - so that is the case - then what ?
THERMALS ! (or some other updraft)
When close to the shore, and the wind is a bit offshore - thermals (hot rising air "bubbles") can be ripped off the ground and go up and out over the water.
As most know, a glider or seagull or eagle circling without flapping its wings - will fly in circles to get the maximum updraft, as it is far more important to STAY IN THE LIFTZONE, than having the lowest sink rate compared to the air.
I've now got 34 years of experience with thermals and flying - and can say for sure, that some just have the "intuitive" natural gift, to find and center thermals.
Others has a bit of natural gift, and a good understanding and experience (knowing what to look for - other birds flying, wind changes in different zones etc.) - which combined gives them the very best ability to find and use thermals to the max
The other thing that can be the case is, that when going down from a jump - you can in fact use ALL energy to get the last hangtime out of a jump - which means your kite will have no energy when you land on the water - but so what
So a well timed kiteloop will give you the last few extra seconds in the air, before touchdown.
Other facts that matter are the actual lift conditions - how are they shaped, how do they "work" etc.
Which may affect ANY logical thinking and experience of course.
But bottom line is - that some are gifted with the ability to find and use lift (like this gifted kid, no doubt
), and that extreme hang time are always a matter of "extreme" lift conditions or wind squalls or rotors, and not "stable" air.
So hang time records will always be a bit "so so" and not something depending on gear and performance - as you can never tell when it is actual lift, or just pure performance from rider and gear
Almost like when a snowkiter goes off a mountain - and could fly for hours if he/she wanted - what is that ?
A hangtime record or just ridge soaring ???
On the other hand - we are all aware from our local spots, that SOME gifted kitesurfers can jump higher and with more hangtime, consistently
That is the true hangtime experts
Kindly, Peter Frank