This position comes with a lot of responsibility as you are the one letting go of the kite so you should also make sure that all is correct in order to avoid an accident.
First of all, you need to pick up the kite and put it in the launching position making the kite perpendicular to the ground, and the leading edge facing the wind, the interior of the kite should be facing its pilot. Loads of people often hold the kite and remain in front of the leading edge. You should avoid this by making sure you hold the kite by having your top hand pushing the kite on the back and the bottom hand pulling towards you. This way you have the kite completely secured, and you can stay behind the leading edge allowing for the kite to fly when it’s all ready.
You will be instructed to let go of the kite once the pilot makes a thumbs up it’s the signal to release but there are more things to consider. Lot’s of pilots don’t know how to position themselves correctly and give the thumbs up when the kite is not well placed causing a potential accident situation. So besides the thumbs up, that signals that the rider has made all his verifications and is ready for you to release, you should check two more things.
First of all, make sure the kite is not flapping, and all the sail is now filled with air. This is the most common mistake as often the rider doesn’t know how to position himself to make sure the kite will fly on launch. If you are given the thumbs up and the kite is still flapping do not let go of the kite and signal the pilot that the kite is not ready. When the kite is fully inflated you even start to feel some pressure from the kite that begins to want to move forward. The rider needs to move towards the wind direction to make the kite filled with air until this has been done do not let go.
The other thing you need to check is that the lines are not crossed. So take a quick look at the four lines and see if they all go straight to the bar without being tangled and that the pilot has the right hand on the right side of the bar (left should be on the red side). Often novice riders grab the bar incorrectly, and if you let go of the kite, the potential accident is high.
So once the kite is completely tense wanting to go, the lines are straight with no tangles and the rider has given the thumbs up you can now release the kite.