Once the kite is airborne there are four forces acting on it: weight, drag, lift and the tension of the string. The lift force is the most important and the one that holds the kite aloft. Lift is generated when air flows over the surface of the kite as it is held at an angle to the wind. This angle is critical and is known as the 'angle of attack'. If the angle is too shallow, there is not much lift generated and the kite falls. If the angle is too steep, the air flow is disrupted by the kite and the kite stalls and falls down. So, being able to control this angle is critical to a successful kite. The higher the kite is, the stronger the wind speed and the greater the lift.
- Placement of the bridle (called 'de loop' by Bermudians). The measurements of these are very precise. The one from the middle must be as long as the top curved section, the two that come from the ends of the curved section must go to an inch below the centre of the kite sticks. If these are incorrect, the angle of attack won't be within flight range.
- The angle and tension of the kite string - must be forwards and downwards! Which is why it is so important to pull downwards a bit on the line as the kite is being thrown upwards when it is being launched.
- The drag and weight of the kite - which is significantly affected by the length and weight of the tail - usually lengths of bed sheets that have been torn up and knotted together. Note that the centre of mass of the kite is moved backwards from the geometric centre by the mass of the tail.
Hummers - these are strips of tissue that are mounted on strings from the headstick to the top of the curved section. They are free to vibrate and produce a loud noise. Hannah's hummers are white with black spots on them. If made from stiff paper (grocery bags) or plastic they can be very loud and extremely annoying!