In our recent introduction to first-person view (FPV) drones, we went over the basics of FPV flying. Specifically, we focused on aircraft requirements, necessary equipment, and FPV use cases. Now, we’d like to expand upon that primer with a glossary of terms and abbreviations commonly associated with FPV drones. Knowing these terms, and understanding why they are important, will benefit you if and when you decide to become an FPV drone pilot.
Acro: Short for acrobatic. When a drone is in acro mode, the pilot has total control over its angular velocity of rotation. In other words: It’s all up to you. The drone will not self-level automatically. It will not “fight” stick input. You can fly the drone however you like, including making it perform loops, rolls, and other acrobatic maneuvers. Acro mode is also commonly known as manual and rate mode.
Air Frame: The air frame (or simply frame) is the body of your drone. Think of it as your drone’s skeleton. It's where all your FPV system components (camera, props, motors, boards, etc.) are housed.
Band: FPV drones transmit video over certain frequencies (or channels). These channels are split into specific groups called bands (Band A, Band B, etc.). Each band has eight specific channels, each with its own unique frequency.
Bando: An abandoned building or structure suitable for FPV operations. Knowing what a bando is doesn’t necessarily enhance your technical knowledge or ability, but it’s fun to say and will definitely make it sound like you know what you’re talking about.
Battery: The battery supplies your drone with power. The most common type of FPV drone battery is a lithium-ion polymer (LiPo) battery, which is a multi-cell battery available with different cell configurations: from one cell (1S) all the way up to eight cells (8S). Generally speaking, more cells equal more power and thus more speed, but they also equal more weight overall, which impacts total flight time.
Brushed: One of the two types of motors commonly used in FPV drones. In general, brushed motors are weaker than brushless motors and typically only used in very small (or micro) FPV drones.
Brushless: One of the two types of motors commonly used in FPV drones. Brushless motors are generally more powerful and more durable than brushed motors, and thus have wider applications.
Camera: The camera is one of the most critical components of your FPV system. Typically, the camera is mounted on the front of the air frame, thus enabling that unique “first-person view,” where it seems as though you are looking through the “eyes” of the drone. Important features to consider when evaluating an FPV drone’s camera system are the field of view, aspect ratio, picture quality, and, perhaps most important of all, latency.
Channel: See band.
ESC: Electronic Speed Controller. ESCs determine how fast and in what direction each motor spins, thus controlling the overall speed. Typically, ESCs are installed individually (1 per arm) or as a 4-in-1 unit (as part of the FC stack). If you’re dealing with a pre-built aircraft, ESCs aren’t something with which you need to be overly concerned. Just know they are largely responsible for your drone’s overall speed.
FC: Flight Controller. If the air frame is the skeleton of your FPV drone, then the flight controller is its brain. All signals pass through this programmable circuit board and are converted into action. If you’re flying any kind of pre-assembled FPV drone, flight controllers aren’t something over which you’ll necessarily need to fret. However, if you are building an FPV flyer from the frame up, there are multiple factors to consider when buying an FC, including the MCU and IMU type, voltage support, and mount style.
FPV: First-Person View. An FPV drone transmits video from its onboard camera system to the pilot on the ground, who then receives that footage in real time using compatible FPV goggles or a monitor. The “first-person” look or perspective of that live footage is where FPV draws its name.
Goggles: FPV goggles are used to stream video from your drone to you in real time. Similar to virtual reality (VR) goggles, FPV goggles feature two small screens that sit directly in front of your eyes. Your FPV goggles receive the video from your drone and then display it on these screens in real time, giving you a live, first-person view of flying from the drone’s perspective.
Freestyle: A type of FPV flying that focuses on acrobatics, exploration, and enjoyment. Unlike FPV racing and photography/cinematography, freestyle flying doesn’t have one specific objective. It’s great for beginners who want to get the feel of FPV flying down. Likewise, it’s where experienced FPV pilots practice tricks, train for a race, or rehearse an upcoming shot. There is no specific set of rules for how to freestyle fly, but there are lots of benefits.
Frequency: FPV systems use specific radio frequencies to transmit and receive signals. With respect to FPV drones, the most common frequencies are 2.4 and 5.8GHz.
Gap: Any small area through which a drone can fly. A common element in both FPV racing and freestyle flying.
Latency: Video latency is a critical factor in FPV flying. It indicates the time delay (or lag) between what you and your drone see. In other words, it’s the amount of time it takes for video to be transmitted from your drone to you. When flying an FPV drone, you want a minimal amount of latency, otherwise you won’t be able to react to your environment in real time, which can result in a crash.
IMU: Inertial Measurement Unit. The IMU is a sensor on your FC board that measures your drone’s orientation and movement. If you’re just starting out with FPV flying or you’re using a pre-assembled craft, the IMU probably won’t show up on your radar. However, what you should know is that the IMU houses an accelerometer and a gyroscope, and these two sensors determine your drone’s flight mode (acro or self-level).
Manual Mode: See acro.
MCU: Micro Controller Unit. The MCU is your FC’s (flight controller’s) processor. Continuing our human-body analogy: If the FC is the brain, then the MCU is sort of like the hippocampus—it’s where memory (firmware) is stored and accessed. The MCU also handles all the complex calculations the FC uses to regulate flight.
Mistakes High: Mistakes high is a variable measurement indicating the level of altitude needed to recover in the event of user or flight system error. For example, if you were flying a drone at an altitude of 80' in an open field, you’d be flying 1 or 2 “mistakes high,” depending on the pilot. In other words, the drone is high enough that you can recover from either 1 or 2 mistakes before crashing.
Motors: The motor assembly is what’s responsible for spinning the props of your FPV drone and providing enough thrust to fly. There are two types of motors commonly used with FPV drones: brushed and brushless.
Multirotor: A multirotor is any aircraft with more than two rotors. It’s one of the many words used interchangeably with “drones.” If you hear someone talking about a multirotor, odds are they just mean drone.
PDB: Power Distribution Board. The PDB regulates how power is distributed throughout your FPV drone. In most builds, the PDB connects directly to the flight battery, and distributes power to the other components.
Pitch: Pitch indicates the direction of the tilt (either up or down) in which a drone is moving along its vertical axis. One way to visualize pitch is to think of your drone’s nose as your own. Moving your nose up and down in a straight line is the same as adjusting your drone’s pitch. Nose goes up, pitch goes up. Nose goes down, pitch goes down.
Propellers: Propellers (or props) are the rotating blades that help propel your FPV drone. They come in different styles and materials, and with different blade counts and other attributes.
Rx: Receiver. The Rx receives signals from the Tx (transmitter) and converts them into usable forms. For example, the video transmitter on your drone transmits signals to a receiver on the ground (e.g., your goggles) and then converts that signal into viewable video. Can also be described as VRx, or video receiver.
Racing: Racing is one of the most popular uses for FPV drones. In an FPV drone race, pilots use FPV equipment to race each other around a predetermined track.
Rate Mode: See acro.
Roll: Roll indicates the direction in which a drone is rotating along its horizontal (longitudinal) axis. A good analogy for a roll is trying to touch your ear to your shoulder. See the way your head tilts? That’s a roll.
Self-Level: Unlike acro mode, self-level mode keeps your drone level even without stick input. In general, there are two types of self-leveling: angle mode and horizon mode. Angle mode is the most restrictive, as it prevents the drone from exceeding certain pitch or roll angles. Horizon mode is slightly less prohibitive, because it allows for controlled rolls, but will still self-level if there is no stick input.
Tx: Transmitter. The Tx transmits signals from your drone to an Rx (receiver) on the ground (e.g., FPV goggles). The Rx then converts those signals from the Tx into a usable form (e.g., a live video feed). Can also be described as VTx, or video transmitter.
VRx: See Rx.
VTx: See Tx.
Yaw: Yaw indicates the direction (either clockwise or counterclockwise) in which a drone is rotating along its vertical axis. If you were flying an FPV drone and you began to yaw left (turn counterclockwise) or yaw right (turn clockwise), it would appear as if you were spinning in a circle.
Understanding these terms and abbreviations isn’t a prerequisite for becoming an FPV drone pilot or enjoying FPV flight, but they are helpful concepts to understand—especially if you’re looking to build your own FPV flyer or trying to decide which equipment to use. Now, as we mentioned before, this is just a starter glossary. There’s a lot more to talk about with FPV drones, and a lot more terms and abbreviations to go over, so stay tuned for future updates, glossaries, and tutorials.
Also, be sure to let us know if there’s a specific FPV topic or component you would like to see covered in greater detail.