Abbreviations and Terminology

Definitions for common terminology

Meteorological Terminology

Term	Definition
ISA	International Standard Atmosphere in which: The air is a dry, perfect gas; The temperature at sea level is 15° Celsius (59° Fahrenheit); The pressure at sea level is 1013.2 mbar (29.92 inches Hg); The temperature gradient from sea level to the altitude at which the temperature is -56.5°C (-69.7°F) is -0.00198°C (-0.003564°F) per foot and zero above that altitude
MSL	Mean Sea Level is the average height above the surface of the sea for all stages of tide
AGL	Above Ground Level is the height of the aircraft above the ground
OAT	Outside Air Temperature is the free air static temperature surrounding the aircraft
Pressure Altitude	Altitude measured from standard sea level pressure (1013.2 mbar, 29.92 in. Hg) by a pressure or barometric altimeter It is the indicated pressure altitude corrected for position and instrument error. In this Manual, altimeter instrument errors are assumed to be zero

Power Terminology

Term	Definition
Maximum Continuous Power Output	The maximum typical power output of a motor averaged over the entire flight
Maximum Instantaneous Peak Power Output	The maximum power output of a motor during any phase of flight, such as when maneuvering

Flight and Powerplant Control

Term	Definition
Throttle Stick	The radio controller stick responsible for throttle control. For Mode 2 controllers, this is the vertical movement of the left control stick. For Mode 1 controllers, this is the vertical movement of the right control stick
Yaw Stick	The radio controller stick responsible for yaw (also called pan) control For Mode 2 and Mode 1 controllers, this is the lateral movement of the left control stick
Pitch Stick	The radio controller stick responsible for pitch control. For Mode 2 controllers, this is the vertical movement of the right stick For Mode 1 controllers, this is the vertical movement of the left stick
Roll Stick	The radio controller stick responsible for roll control. For Mode 2 and Mode 1 controllers, this is the lateral movement of the right control stick
Pitch/Roll Stick or Cyclic Stick	The radio control stick responsible for both pitch and roll control For Mode 2 controllers, this is the right stick

Weight and Balance

Term	Definition
Maximum Takeoff Weight (MTOW)	Maximum allowable weight at liftoff
Standard Empty Weight	Weight of a standard aircraft
Basic Empty Weight	Standard empty weight plus optional equipment
Useful Load	Difference between take off weight and basic empty weight
Payload	Useful load less battery weight

General Terminology

Term	Definition
LOS	Loss of Signal
RTH	Return-to-Land
sUAS	Small Unmanned Aircraft System includes all components of the system required for the flight of an unmanned aircraft, including the radio controller, data link and other related support equipment