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.
The Grand Canyon is a gorge carved by the Colorado River and is contained in the Grand Canyon National Park in Arizona, one of the first national parks in the United States. According to scientific research the canyon was created by the Colorado River over a period of six million years.