While at Fanø, I setup the a NPWC v7 to fly on two lines. This has a few advantages:
- Easier for a first time flyer to control a kite: Just steering rather than steering and controlling the AOA. When flying a NPWC, there is a small range of adjustment between luff and stall. One reason for this is that there is little pull on the front lines. This has the effect of making the adjustment range even smaller.
- The two line attachment point indicates exactly where the bridle can be cut to provide the right line lengths to fly using handles.
Simple Bridle
The picture below shows the main idea: For each side of the kite, a long loop (red) is run from the top attachment point to the bottom attachment point of the kite. A short loop with knot (blue) is attached to the loop bridle using a prussic knot. The flying lines are attached to the knot on the short loop.
The long loops I use are 5.25 m. After tuning, the attachment point was 280cm from the top canopy bridle point (245cm from bottom bridle point). I.e. the distance from the top attachment point is slightly longer that from the lower attachment point. The prussic knots allow easy adjustment of the attachment point, which could be slightly higher or lower depending on the kite.
Prussic Knot
The pictures below expand on creating a prussic knot loop to make an adjustable bridle. The pink line is the long bridle loop, the orange line is the small loop with kite line attachment knot.
Looping the small loop over the bridle one time creates a larks head knot. This is a great knot for many purposes, but it is not designed to hold a bridle setting.
Looping the small loop over the bridle a second time creates a prussic knot. When tightened, this knot will hold the bridle setting quite firmly.
This is what the prussic looks like when tightend.
Closeup of a tightened prussic knot from the front and from behind.
To adjust the prussic, pull on the pink line on both sides of the knot to straighten it out. The prussic knot may then be slid up or down the pink bridle line to adjust the AOA of the kite.
Remember to tighten the knot (so it looks like the previous picture) after adjusting.
Four Line Conversion
Once the proper bridling point for two line flying is found found, it is easy to convert this to 4 line flying on handles: Cut the pink line at the point where the small loop is attached, then tie knots on the cut ends for four line attachement points. Conversion back to 2 line flying is by using the small loop with a larks head to join the two lines on each side of the kite.
