Aviation Glossary
27 essential terms every drone pilot should know.
A
- AGL
- Above Ground Level — altitude measured from the ground directly below the aircraft.
- ACS
- Airman Certification Standards — FAA document defining knowledge, risk management, and skill requirements for airman certification.
- ATC
- Air Traffic Control — ground-based service that provides traffic separation and information to aircraft in controlled airspace.
- Airspace Class B
- Controlled airspace surrounding the busiest airports. Extends from surface to 10,000 feet MSL. Requires ATC clearance.
- Airspace Class C
- Controlled airspace surrounding airports with an operating control tower and radar approach control. Requires two-way radio communication.
- Airspace Class D
- Controlled airspace surrounding airports with an operating control tower. Extends from surface to ~2,500 feet AGL.
- Airspace Class E
- Controlled airspace that is not Class A, B, C, or D. Often extends from 700 or 1,200 feet AGL upward.
- Airspace Class G
- Uncontrolled airspace. No ATC authorization required for Part 107 operations.
C
- CFR
- Code of Federal Regulations — Part 107 is in 14 CFR.
D
- Density Altitude
- Pressure altitude corrected for non-standard temperature. Higher density altitude means thinner air and reduced performance.
F
- FAA
- Federal Aviation Administration — US government agency responsible for regulating civil aviation.
- FCC
- Federal Communications Commission — regulates radio frequency use by drones.
G
- GPS
- Global Positioning System — satellite-based navigation used for positioning, altitude hold, and RTH.
I
- IMU
- Inertial Measurement Unit — sensor package (accelerometers + gyroscopes) that helps stabilize the drone.
L
- LAANC
- Low Altitude Authorization and Notification Capability — automated system for near-real-time airspace authorization.
M
- METAR
- Meteorological Aerodrome Report — hourly aviation weather observation.
- MSL
- Mean Sea Level — altitude measured from average sea level.
N
- NOTAM
- Notice to Air Missions — advisory containing information about hazards or airspace restrictions.
P
- Part 107
- 14 CFR Part 107 — FAA regulation governing commercial small UAS operations under 55 pounds.
- Pressure Altitude
- Altitude indicated when altimeter is set to 29.92 inHg (standard pressure).
R
- Remote PIC
- Remote Pilot in Command — person with final authority and responsibility for drone flight safety.
- RTH
- Return to Home — automated feature that brings the drone back to its takeoff point.
S
- sUAS
- Small Unmanned Aircraft System — aircraft + controller + communication links, under 55 lbs.
T
- TAF
- Terminal Aerodrome Forecast — aviation weather forecast for a specific airport.
V
- VLOS
- Visual Line of Sight — ability to see the drone with unaided vision at all times. Required under Part 107.
- VFR
- Visual Flight Rules — rules for when pilot can navigate visually. Part 107 operations are VFR-only.
W
- Waiver
- FAA authorization to deviate from certain Part 107 rules (e.g., night flying, BVLOS).