Flowform FF03A

The flowform FF03A is a modified version of the FF03 (American Flowform). The keel height is reduced to get a stable flight even in larger wind speeds. The height of the inlet is reduced to prevend possible folds on the upper leading edge.

Like the FF03 this kite is built with 4 chambers and 3 keels, too. The 2 center chambers are open at the trailing edge (jet chute). The internal pressure exchange is made by the area at the trailing edge with the shortened inner ribs.

All values are related to the base line of the profile (lower leading edge to trailing edge = 100). With the given datas you should calculate all pieces of the kite depending on your chosen size. The profile base line should be 2.5 metre or less.

Profiles (P1-P2-P2-P2-P1)

The outer ribs (P1) are made complete and the inner ribs (P2) are truncated far from the the trailing edge. The rest of the rib is formed by pieces of line or stripe. These hold the top and bottom surfaces together at the back of the kite and prevent "bulges" forming. All profiles are made without vents.

P1              P2
Xp      Yp      Xp      Yp
--------------------------------
0       0       0       0
-10.778 17.269  -10.778 17.269
-9.561  17.951  -9.561  17.951
-6.518  19.379  -6.518  19.379
-3.474  20.490  -3.474  20.490
0.000   21.451  0.000   21.451
2.612   21.994  2.612   21.994
8.699   22.775  8.699   22.775
14.786  23.007  14.786  23.007
20.873  22.803  20.872  22.803
26.959  22.245  26.959  22.245
39.133  20.294  39.132  20.294
51.306  17.493  51.306  17.493
63.480  14.045  60.000  15.089
75.653  10.055  60      0
87.827  5.550   0       0
93.913  3.092
100.000 0.483
100     0
0       0

Xp      Ph
----------------
65      13.575
70      11.972
75      10.282
80      8.506

Keels (K1-K2-K1)

The outer keels (K1) have a length like the base line of the outer profile (P1). The inner keel (K2) have a length like the base line of the center profile (P2).

K1              K2
Xp      Yp      Xp      Yp
--------------------------------
0       0       0       0
0       -34.511 0       -34.511
100     0       60      0
0       0       0       0

Bottom surface (C1U-C2U-C2U-C1U)

Length: 100 (theoretical)
Width: 80 (complete)
Chamber width: 20

Air flow holes:
The air flow holes are placed in the middle of the chamber width on the given distance to the leading edge of the bottom surface.

                C1U     C2U
--------------------------------
Distance LE     20      40
Diameter        5       5

Top surface (C1O-C2O-C2O-C1O)

Length: 115.150 (theoretical)
Width: 80 (complete)
Chamber width: 20

Air flow holes:
The air flow holes are placed in the middle of the chamber width on the given distance to the leading edge of the top surface.

                C1O     C2O
--------------------------------
Distance LE     83.035  41.780
Diameter        5       5

Jet chute

First make the jet chut on the bottom surface, than make it in the same way on the top surface. To make the jet chute use half a circle with a radius of 20 at the center of the trailing edge. Sew the bottom surface and the top surface on both sides of the jet chute beginning on the trailing edge on a length of about 15 together.

An alternative way to make the jet chute is to use straight lines on the surfaces in stead of a half circle. One edge of the jet chute at the trailing edge is set to the position 0-0. Then it is possible to make the jet chute with the given datas:

Bottom side     Top side
Xp      Yp      Xp      Yp
--------------------------------
0       0       0       0
5       15      5       15
20      20      20      21.5
35      15      35      15
40      0       40      0

Bridle lines (B2-B1-B2)

Bridle line: 1.5mm polyamide (for 2 metres spanwidth)

B1      B2
----------------
200     204