BETAFPV Air 1S Brushless FC 4IN1 – 2.9g, G473, 5A ESC, VTX

When every gram counts, the BETAFPV Air 1S Brushless FC is the board racers reach for. At just 2.9g in its 4IN1 form, it combines the flight controller, ESC, OSD, and a 25–400mW analog VTX on a 0.8mm ultra-thin PCB. You can build a seriously light whoop around it.

Don't let the weight fool you: it was the first 1S flight controller to use the STM32G473 processor (168MHz), which BETAFPV says is about 55% faster than the F411 it replaced. Pair that with the ICM42688P gyro (up to 8K sample rate) and 16MB of blackbox memory, and you get quick, precise response for racing and tight freestyle lines.

Why the 4IN1? It skips the onboard receiver so you can choose your own, and the obvious match is BETAFPV's ELRS Lite Receiver (sold separately). The Lite weighs about 0.47g, measures roughly 10mm square, and runs ExpressLRS 2.4GHz over a CRSF serial connection. The board reserves three full-featured UARTs, so there's room for the Lite plus GPS, an HD VTX, or other serial gear.

Heads up: This is a pilot's board. The thin PCB and solder-only motor pads are built for advanced builders chasing minimum weight. If you want something tougher and more beginner-friendly, check out the Matrix 1S 5IN1 II.

• Integrated: FC + 5A ESC + OSD + 5.8GHz VTX (no receiver)
• Pairs with: BETAFPV ELRS Lite Receiver (sold separately)
• Weight: 2.9g | Mounting: 26 × 26mm | PCB: 0.8mm
• MCU: STM32G473CEU6 | Gyro: ICM42688P | Blackbox: 16MB
• ESC: 1S, 5A continuous, Bluejay, DShot300/600
• VTX: 25 / 100 / 200 / 400mW + pit mode, 48 channels, SmartAudio 2.0
• BEC: 5V 3A | USB: SH1.0 4-pin
• Firmware: Betaflight 4.5.0 (BETAFPV G473 target)

Includes: Air 1S Brushless FC (4IN1), Type-C to SH1.0 adapter, SH1.0 4-pin adapter cable, 5.8G VTX antenna, 40mm BT2.0 U whoop cable pigtail, 4× M1.4×4 self-tapping screws, 4× shock-absorbing balls. Receiver sold separately.

Common Questions

What's the difference between the 4IN1 and 5IN1?
The 4IN1 has the FC, ESC, OSD, and VTX. The 5IN1 adds a built-in ELRS 2.4GHz receiver. The 4IN1 is lighter (2.9g vs 3.6g) and lets you choose your own receiver.

What receiver should I use?
BETAFPV's ELRS Lite Receiver is the one they recommend for this board. It's a tiny ExpressLRS 2.4GHz receiver with CRSF serial output. It needs a 5V power wire, a ground wire, and TX/RX wires to a spare UART, and it ships with four thin silicone wires for the job. The VTX uses UART2 by default.

How do I set up and bind the Lite receiver?
In Betaflight, open the Ports tab, switch on Serial RX for the UART you wired it to, and choose CRSF as the receiver protocol. To bind, plug and unplug the flight controller three times until the receiver LED does a quick double blink. Then put your radio into bind mode, and a solid light means it's bound.

Is this good for beginners?
It's aimed at advanced pilots who want the lightest build possible. The board is very thin and the motors must be soldered directly, so it takes some soldering confidence. Newer pilots will likely prefer the Matrix 1S 5IN1 II, which is tougher and has plug-in motor connectors.

What does it fit?
It uses a 26×26mm mounting pattern. BETAFPV recommends it for the Air65 and Air75 whoops, and it works with Meteor65, Meteor65 Pro, and Meteor75 Pro frames and 0702, 0802, or 1102 motors.

Any tips for soldering and VTX safety?
Solder the motor wires directly, since there are no plug-in connectors on this board. Keep the iron under 370°C and limit each joint to 1–2 seconds so you don't lift a pad. Always connect the VTX antenna before powering on (or set VTX power to zero), and use 25–100mW indoors for better flight time.