User Guide

Ground effect. Air “cushion” produced when a helicopter hovers at low altitude.
Gunship. Slang for an armed attack helicopter, or an armed, non-fighter plane.
Helicopter. Rotary-winged aircraft that flies horizontally and vertically using lift created by a powered rotor system.
Helmet Reticle. Small circular “glass” positioned over the pilot’s right eye that superimposes important com-
bat and flight information over a camera image of the outside world.
Hover hold. Maintaining a constant position at a constant altitude.
Jammer. Source of intense infrared or radio energy used to confuse guided weapon systems.
Klick. Slang for kilometer.
Knot. Unit of horizontal motion equal to 1.1 mph (approximately 6,076 ft/hr or 1 nautical mile/hour).
Lift. Upward force produced as air passes over an airfoil. Pressure above the airfoil surface is less than that
below the airfoil, which causes the lifting force.
Terrain masking. The tactic of using naturally occurring objects as cover from the enemy.
Nautical mile. Aeronautical unit for measuring distances (see knot).
Platoon. U.S. military unit just below a company with anywhere from 25 to 50 soldiers.
Point of impact. Point along the leading edge on an airfoil where the air separates over the top and bottom.
Pull pitch. To quickly add collective.
Rate of climb. Vertical rate of ascent, measured in feet per second (ft/sec) or meters per minute (m/min).
Rotational velocity. Speed of the blades as they rotate around a center point. Also called angular velocity.
Rotor. Engine-powered system in a helicopter that creates lift. A rotor consists of a main shaft that turns and
rotates from two to four blades in a circular motion. The pitch of the airfoils (blades) creates lift.
Settling with power. Condition that occurs with a vertical descent at low forward airspeed. The speed of
airflow through the rotor is slower than the rate of descent, causing lift in a downward direction.
Shaft horsepower. Power rating for helicopter engines.
Side slip. “Skidding” condition that occurs when the helicopter is in forward motion and turns sharply. The
aircraft temporarily slides in the original direction of motion, regardless of the helicopter’s current heading.
Slick. Slang for unarmed transport helicopter.
Tail rotor. Small vertical rotor system mounted on a helicopter’s tail. This rotor pushes the tail left and right,
helping to counteract the torque produced by a single-rotor helicopter.
Thermal Imager. Night-time vision system similar to FLIR, but recognizes moving objects.
Translation tendency. Tendency of a single-rotor helicopter to drift to the right while hovering. This is due to
the force created by the anti-torque (tail) rotor.
Translational lift. Additional lift produced by horizontal airspeed. When the helicopter moves from a hover
into forward motion, the relative wind passing over the tilted rotor blades creates more lift.
Weapons Free. Term signalling full freedom to utilize weapons against targets.
Weapons Hold. Term signalling crews to hld their weapon fire.
C: GLOSSARY
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