**DRAW the FORCES of a KITE**- Draw the diagram of forces of a kite let determine the aerodynamic thrust of the windl on the kite.

The diagram also lets better understanding of the behavior of the kite.

**FORCES AT EQUILIBRIUM**- Here is the general arrangement of the forces of a kite. The forces as shown are the resultants of all forces. However, some may prefer to draw apart the forces of a tail or a drogue.
- These forces are when the kite is at equilibrium
- R is the retaining force on the line
- P is the thrust of the wind
- which components are lift L and drag Q
- W is the weight
- a is the incidence angle of the kite
- q is the line angle at the bridle.
- To be successful, it must be set up:
- – the incidence angle a,
- – the pull on the line, R
- – the line angle q
- – the weight of kite, W
- – the position of the center of gravity.
- - the bridle point

**MEASURES ON THE FIELD**- ¤ Fly the kite at 20/30m
- ¤ Measure the line angle
- ¤ Let's walk leeward until being aligned with the outline of the kite and measure the incidence angle

**MEASURES AT HOME**- ¤ Scale the kite.
- ¤ Hold the kite by the bridle ring. The vertical from the ring gives the center of gravity on the spine.
- The spine on cellular kites is through the center of the cells.

**DRAW THE DIAGRAMME**

- ¤ Draw the spine and the bridle
- ¤ Incline at incidence angle

- ¤ Draw the vertical through the center of gravity
- ¤ Draw the line through the bridle ring inclined as the line angle.
- These two lines intersects at J.

- ¤ Draw the vectors
- – on the vertical line JK = W
- – on the oblique line KM = R

¤ From M draw MJ and extend until the spine

¤ Show the aerodynamic thrust P = JM.

Graphically, size P, its location on the spine, its inclination.