DD system

**DD
system**
developed by
Gradient is a system of double diagonal Ribs or double
diagonal
segments. These double diagonals enable to add two cells between
attached loops
without the necessity of increasing the number of loops. Thanks to that
the
number of carrying ribs and loops is significantly reduced while the
number of cells
is preserved. As a result the total length of used lines is
substantially lowered
and the aerodynamic drag is reduced.

The DD system was first used in the Aspen4 glider(introduced in 2011)
and in comparison with its predecessor Aspen3 the total line length was
lowered by 37%. Today this DD system is one of the cornerstones of
high-performance gliders.

The DD system is used in these gliders: Aspen4, Nevada, Golden4, Aspen5, Avax XC5, and Nevada2.

Pros:

Reduction of the number of carrying ribs
while the number of cells is preserved

Improvement of the compactness of the
glider

Reduction of the total line length and
reduction of the aerodynamic drag.

Better aerodynamic cleanness of the glider

Cons:

Increase in laboriousness and required accuracy during the production

More complicated tuning of the glider