HELI-90/120/140 refers to a helicopter, with the servos orientated at 90 degrees (2 servos, generally beginner helicopters with forward, back, right, and left movement on the cyclic stick), 120 degrees (3 servos- generally for more advanced helicopters that have collective pitch controls on the rotor blades (yes, this means inverted flight too)), ...
canyon. n. 1. (Physical Geography) a gorge or ravine, esp in North America, usually formed by the down-cutting of a river in a dry area where there is insufficient rainfall to erode the sides of the valley.
A gorge or canyon (canon, caÃ±on old spelling occasionally still) used is a deep ravine between pairs of escarpments or cliffs and is the most often carved landscape by the erosive activity of a river over geologic. timescaleshe word canyon is generally used only in North America, while the words gorge and ravine are used in Europe and Oceania, though gorge and ravine are also used in some parts of North America.