The horizontal stabilizer (the tail) is designed to increase a hang glider pitch stability. Although it was designed and tested for Aeros hang gliders, it can be also mounted to any other hang glider as well.
The tail allows flying with lower sprogs settings keeping DHV required pitch-up moment.
The diagram below is taken from the DHV tests and shows the momentum distribution of the same glider with four different setups when driving with the test vehicle from 40 to 100 km/h. The red line shows the DHV required pitch. The blue line shows pitch for glider without the tail with sprogs set 2 deg. lower than DHV certification with VG on. The yellow line is for the same glider with the tail and VG on. The dark green line is for the same glider with the tail and VG off. For all 3 drives (glider without tail -VG 100%, glider with tail VG 100% and glider with tail VG 0%) the sprogs were set to the same level.
After numerous flight tests and competition flights it was determined that the tail greatly increase not only the pitch stability but the directional stability as well. Properly adjusted hang glider with the tail retains the same good handling, but the tail adds directional stability and makes the glider pleasure to glide at higher speed in turbulent air, bringing significant gain in performance when flying in turbulent air.
The difference you can see at these two tracks taken from the real track log on final glide of two gliders – one (lower one) with the tail, another one (higher one) – without.
Surprisingly enough, the glider with a tail is more comfortable and easier to land than the tailless glider.
DESCRIPTION AND TECHNICAL INFORMATION
The tail has symmetrical low drag profile and is rigidly mounted at 5 deg. negative angle of attack to the slightly extended keel tube. The tail consists of three parts: the center tail section and the left and the right outer tail sections. It is made of stiff light weight carbon fiber and strong enough to withstand a point loading. It can be easily stored when de-rigged and packed in a glider bag or in a harness bag.
Span 1600 mm
Tail area 0.25 sq. m
V-angle +4 deg
Mounting angle -5 deg