Glossary

Drone terminology glossary

KVRPM per volt with no load — it defines a motor's character: high KV means speed, low KV means torque and efficiency

LiPoLithium-polymer battery — high energy density and strong discharge, and it demands careful handling

Li-IonLithium-ion cells (21700) — more capacity, gentler discharge, ideal for long range

C-RatingMaximum discharge rate of a battery = capacity × C

ESCElectronic Speed Controller — governs the speed of each motor

FCFlight Controller — the brain of the aircraft (gyro + processor)

PIDThe stabilisation control algorithm — how you tune it defines how the aircraft feels

BetaflightThe best-known open-source firmware for FPV drones

iNavFirmware oriented towards navigation, GPS and long range

ArduPilot / PX4Autonomous industrial mission systems (waypoints, missions)

FPVFirst Person View — flying through the aircraft's camera

VTXVideo Transmitter — the onboard video sender

OSDOn-Screen Display — flight data overlaid on the video feed

ELRSExpressLRS — open-source radio system, the current standard

CrossfireTBS long-range system on 915/868MHz

UARTA serial port on the FC used to connect peripherals

DShotDigital protocol between FC and ESC (DShot300/600)

FailsafeWhat the aircraft does on signal loss — drop, or GPS return

RTH / GPS RescueAutomatic return to the take-off point

HoverHolding position at a single point in the air

Pitch (propeller)The theoretical distance a propeller advances in one revolution

Thrust-to-WeightThrust-to-weight ratio — 2:1 is the minimum for comfortable flight

CGCenter of Gravity

BECA voltage regulator feeding the FC and peripherals from the main battery

Soft-mountRubber mounting that isolates frame vibration from the gyro

Smoke StopperA safety tool that stops a short circuit from burning your components

BindingPairing the transmitter to the receiver

Acro / AngleFlight modes: fully manual / self-levelling

CinewhoopA small filming drone with ducted prop guards

Tiny WhoopThe smallest class — indoor and training

Long-RangeThe 7-inch class on Li-Ion packs, for large distances

RTKCentimetre-accurate GPS correction for surveying and precision missions

GimbalA mechanical camera stabiliser on powered axes

WaypointsProgrammed route points for an autonomous mission

IMUInertial Measurement Unit — gyro plus accelerometer, the key sensor for reading aircraft attitude

PDBPower Distribution Board — splits battery current to the ESCs and regulates peripheral voltages

BMSBattery Management System — protects against overcharge and deep discharge, and balances cells

TelemetryA two-way data link relaying live aircraft status to the ground station

Optical FlowA downward-facing optical sensor that enables stable hover indoors without GPS

LiDARA laser that builds a 3D point cloud — for obstacle avoidance and terrain survey

MonocoqueA structure where the outer shell itself carries the loads — like an eggshell

Stator / Rotor BellThe fixed windings inside the motor versus the rotating magnet-carrying housing

CW / CCWThe two propeller rotation directions — opposed, to cancel yaw torque and stop the aircraft spinning

EO/IRPaired electro-optical and thermal sensors — for search and rescue and industrial inspection

Arm / BoomThe arm carrying the motor and propeller — carbon fibre, to limit resonance

Motor MountThe motor mounting plate — its job is absorbing vibration before it reaches the gyro

Airframe / ChassisThe core structure of the aircraft — H-frame, X-frame or True-X

Point CloudThe 3D output of a LiDAR survey

Base StationThe ground reference station that sends RTK corrections to the aircraft

Frequently asked questions

What is the difference between an FC and an ESC?

The flight controller is the brain — gyro plus processor — that decides how fast each motor should turn. The ESC is the electronic speed controller that actually executes that decision at the motor. They communicate over a digital protocol such as DShot300 or DShot600.

What does failsafe mean?

The aircraft's programmed behaviour when it loses the control link — either an immediate drop or an automatic return to the launch point via GPS Rescue or RTH. Testing it before each session is not optional; it is the difference between an aircraft that comes back and one that is lost.

What is thrust-to-weight ratio?

Total motor thrust divided by all-up weight at take-off. A 2:1 ratio is the minimum for comfortable, controllable flight; below that the aircraft responds slowly and cannot correct for wind.

ELRS or Crossfire?

ELRS (ExpressLRS) is an open-source radio system that has become the current standard on reach, price and performance. Crossfire is a Team BlackSheep system running on 915 and 868MHz, known for long-range reliability. Both are alternatives to closed manufacturer systems.