Every acronym and bit of jargon you'll run into in this hobby, defined the way I'd explain it at the field.
The standard channel order on many radios: Aileron, Elevator, Throttle, Rudder — channels 1 through 4. Futaba and FrSky use AETR; Spektrum uses TAER (throttle first). It matters when you plug servos into the receiver: get the order wrong and your sticks move the wrong surfaces.
The hinged flaps on the outer trailing edge of the wing. They move in opposite directions — one up, one down — to roll the plane and bank it into turns. On most planes, ailerons are your main turning control.
A kit where the airframe is mostly built, but you supply and install all the electronics: motor, ESC, servos, receiver, and battery. More work than a PNP, but you get to pick every component — which is half the fun if you like the building side of the hobby.
A Battery Eliminator Circuit is a voltage regulator that steps your flight battery's voltage down to around 5V so the receiver and servos don't fry. Most ESCs have one built in. A UBEC is the same thing as a separate unit, used when the built-in BEC can't supply enough current — say, on a plane with lots of big servos.
The one-time pairing process that links your receiver to your transmitter, like pairing Bluetooth headphones to your phone. Once bound, the receiver only listens to your radio — not the guy flying next to you. Every brand has its own bind procedure, usually involving a button or plug and a specific power-up order.
The motor type in nearly every modern electric RC plane. No brushes to wear out, way more power for the weight than old brushed motors, and they run for years. They need an ESC to work — you can't just wire one straight to a battery. My recommended gear page lists the motors I actually fly.
A LiPo's maximum continuous discharge rating, written as a multiple of its capacity. Multiply the two: a 2200mAh (2.2Ah) pack rated 25C can deliver about 55 amps continuously. Your battery's C-rating times its capacity needs to comfortably exceed what your motor pulls at full throttle — the full math is in my LiPo basics guide.
The balance point of your plane, and the single most important number for a first flight. On a conventional plane it usually sits around 25–33% back from the wing's leading edge. Nose-heavy flies sluggish but safe; tail-heavy is a crash waiting to happen. The Airplane Designer marks the CG on a to-scale plan for your build.
One controllable function on your radio. A basic 4-channel plane uses throttle, ailerons, elevator, and rudder. Extra channels handle flaps, retracts, lights, or camera gear. A "6-channel radio" can control six separate things — buy more channels than you need today, because you'll grow into them.
The front-to-back width of the wing, measured from leading edge to trailing edge. Lots of design numbers are given as a percentage of chord — CG location, control surface size — so it's worth knowing. On a tapered wing, people usually work from the average (mean) chord.
The upward V-angle of the wings when you look at the plane from the front. Dihedral makes a plane self-level: when it banks, the geometry gently rolls it back toward wings-level. That's why trainers have lots of it and aerobatic planes have almost none — stability and agility pull in opposite directions.
The hinged surface on the horizontal tail that pitches the nose up or down. Pull the stick back, elevator goes up, nose comes up. Despite the name, it doesn't directly make the plane climb — it points the nose; the throttle does the climbing.
A control surface that does two jobs at once: elevator plus aileron. Flying wings have no tail, so their two trailing-edge surfaces mix both functions — move together for pitch, opposite for roll. Your transmitter or flight controller handles the mixing; you just fly it like a normal plane.
The box between your battery and motor that controls how fast the motor spins based on your throttle stick. It's rated in amps — pick one comfortably above your motor's maximum draw. Most also include a BEC to power your receiver and servos. The Wiring Designer shows exactly where the ESC connects in your setup.
Short for exponential — a transmitter setting that softens stick response around center while keeping full throw at the ends. With some expo dialed in, small corrections feel smooth instead of twitchy, but you still have full control authority when you shove the stick over. Most pilots run 20–40% on ailerons and elevator.
Hinged surfaces on the inner trailing edge of the wing that both drop down together. They add lift and drag, letting the plane fly slower for landing without stalling. Not the same as ailerons — flaps move together; ailerons move opposite. Plenty of great planes don't have them at all.
A plane that's all wing — no fuselage, no tail. Simple to build, tough, fast, and a favorite for FPV. The catch: with no tail, they need a correct CG and reflex to fly stable. I learned that the hard way in my flying wing fail-to-flight build.
Paper-faced foam sheet — the stuff from the dollar store or craft aisle — and the backbone of cheap scratch building. It cuts with a hobby knife, glues with hot glue, and a whole airframe costs a few bucks. Crash it, laugh, build another one. It's the cheapest way into this hobby by a mile.
Flying with a live video feed from a camera on the aircraft, watched through goggles or a screen — like sitting in the cockpit. It's a whole sub-hobby with its own gear: cameras, video transmitters, goggles. In the US, note that FAA rules require a visual observer when you fly FPV.
A brushless motor spec: RPM per volt, with no propeller attached. A 1000Kv motor on a fully charged 3S pack (~12.6V) spins around 12,600 RPM unloaded. Lower Kv means more torque for swinging big, efficient props; higher Kv spins small props very fast. It is not a power rating — a 2200Kv motor isn't "stronger" than a 1000Kv one.
The battery that powers almost every electric RC aircraft. Huge power for the weight, but it demands respect: charge with a proper balance charger, never below about 3.5V per cell in flight, and store at roughly 3.8V per cell. Get these habits wrong and packs puff, die early, or catch fire. Full rundown in my LiPo basics guide.
Battery capacity — how much energy the pack holds, and roughly how long you can fly. A 2200mAh pack holds twice the energy of an 1100mAh pack, but it's also heavier, so bigger isn't automatically better. The number also sets your charge rate: charging at 1C means 2.2A for a 2200mAh pack, which I walk through in my charger amp settings guide.
A mount that holds the motor above or behind the airframe instead of in the nose — common on gliders, flying wings, and simple foam board builds. Pods keep the prop out of the dirt on belly landings and make pusher setups easy. Usually just a piece of plywood or a 3D-printed bracket.
A plane that arrives with motor, ESC, and servos already installed — you add your own receiver, battery, and transmitter. It's the sweet spot once you own a good radio: every new PNP plane binds to the transmitter you already have, so you're not paying for (and landfilling) a cheap radio with every purchase.
Props are sized as diameter x pitch, in inches. A 9x4.7 prop is 9 inches across, and its blade angle would screw it 4.7 inches forward in one revolution (like a bolt through wood). Low pitch gives thrust and acceleration for slow flyers; high pitch gives speed. Never go bigger than your motor and ESC can handle — more prop means more amps.
A plane with the prop behind the wing pushing, instead of in front pulling (a "tractor" setup). Pushers are popular for FPV and trainers because the prop is protected in crashes and there's nothing spinning in front of the camera — or your fingers on a hand launch. Watch your knuckles on release, though.
The small circuit board in the plane that picks up your transmitter's signal and passes commands to the ESC and servos. It has to match your transmitter's protocol — a Spektrum receiver won't talk to a FrSky radio. The Wiring Designer shows what plugs into which receiver port for your exact setup.
A slight upward bend or trim at the trailing edge of a flying wing. Because a wing has no tail to provide pitch stability, the reflexed trailing edge does that job instead. Skip it and the wing tucks into the ground — it's one of the fixes that got my flying wing from lawn dart to flyer.
Everything in one box: plane, electronics, transmitter, battery, and charger. Charge it and fly the same day. The included radios are usually basic, but for a first plane, RTF removes every excuse — my Start Here guide covers when RTF makes sense versus building your own.
The hinged surface on the vertical tail that yaws the nose left and right. It won't turn a plane efficiently on its own — that's the ailerons' job — but it's essential for coordinated turns, crosswind landings, and ground steering. On simple 3-channel trainers with lots of dihedral, the rudder does double duty as the turning control.
A small geared motor with a rotating arm that physically moves your control surfaces. Stick input goes transmitter → receiver → servo → pushrod → surface. Sized by weight — 9-gram servos handle most foam planes. Metal gears cost a little more and survive crashes that strip plastic ones.
The stiff spine running along the wing, spanwise, that keeps it from folding under load. In foam board builds it's often a wooden dowel, carbon tube, or even a paint stir stick. Skipping the spar works fine right up until you pull out of a dive and the wings clap hands above the fuselage.
Live data sent back from the plane to your transmitter — battery voltage, signal strength, altitude, sometimes GPS. The killer feature is a low-voltage alarm: your radio beeps when the pack gets low, so you land on time instead of gliding home dead-stick. Needs a telemetry-capable receiver and radio.
Static thrust divided by the plane's total flying weight. Around 0.5:1 flies a trainer or glider fine, 1:1 will hover or climb straight up, and more than that is 3D aerobatics territory. The Airplane Designer estimates it for your motor and prop combo before you build.
The radio in your hands. It's the one piece of gear that follows you from plane to plane for years, so it's worth buying a decent one early — a good radio binds to every model you'll ever own. My picks are on the gear page.
Small adjustments — the little buttons or sliders next to each transmitter stick — that shift a control surface's neutral position. If your plane drifts left with your hands off the sticks, a few clicks of right trim fix it. Trimming a plane to fly hands-off straight and level is the first job of every maiden flight.
The plane's weight divided by its wing area, usually in ounces per square foot. It's the best single predictor of how a plane flies: low wing loading floats and lands slow (trainers, gliders); high wing loading is fast and lands hot (warbirds, jets). Punch your numbers into the RC Calculators to see where your build lands.
A 12V addressable RGB LED strip — every LED can be a different color, controlled by a single data line, with a backup data line so one dead LED doesn't kill the rest of the strip. The 12V supply means less voltage drop over long runs than 5V strips like the WS2812B. It's what I use for aircraft lighting; the full story is in my WS2815 lighting guide.
Missing a term you keep seeing? Send it my way and I'll add it. And if the definitions here made you want the bigger picture, RC Electronics Explained connects all these parts into one working airplane.
The free tools turn these terms into answers for your exact build: CG location, wing loading, wiring diagrams, and a parts list.
