On the other hand, if you have wings with about 70 to 80 percent double surface, your cruise speed can go as high as 70 to 80 kmph. Generally, a wing with a 30 percent double surface can fly as fast as 50 to 60 kilometers per hour (kmph).
The rule of thumb is, the wing is faster if the extent of the double surface of the wing is larger.
The speed at which a powered hang glider fly depends on several factors including the surface of the wings and the power of the engine.
