FPV Fixed Wing Setup: INAV Configuration, Auto-Launch, and Mixed Flight Modes — 2026 Guide

Fixed wing FPV is a different animal. Your flight controller isn’t just stabilizing — it’s flying the plane when you’re not, managing stall speeds, executing autonomous missions, and launching the aircraft while your hands are on the goggles. After building and flying 15+ fixed wing FPV rigs from sub-250g nano wings to 2-meter endurance platforms, here’s what actually matters.

Flight Controller Selection: Not All FCs Work for Wings

The FC that powers your 5-inch quad is probably wrong for a wing. Wings need specific hardware:

Dedicated wing FCs like the Matek F405-WMN or SpeedyBee F405 Wing Mini have these baked in. A quad FC can work in a pinch but you’ll lack the barometer and servo rail — you’ll wire servos to motor outputs, which is messy and limits your channel count.

INAV Configuration: The Key Differences from Betaflight

INAV shares DNA with Betaflight but the configuration philosophy is different. Betaflight is about keeping a quad in the air for 3–5 minutes of aggressive flying. INAV is about flying efficiently and returning home safely after 30+ minutes.

Ports Configuration — Get This Right First

UART1: Serial RX (ELRS/Crossfire receiver)
UART2: GPS (TX→RX, RX→TX)
UART3: DJI O4 / Walksnail MSP (DisplayPort for OSD)
UART4: Compass (I2C — SDA/SCL)

The single most common failure mode: GPS on the wrong UART with the wrong baud rate. INAV expects GPS at 115200 baud by default. If your GPS module defaults to 9600 (many BN-220 clones do), you’ll get “No GPS fix” forever without any error message. Configure the UART baud rate in the Ports tab before doing anything else.

Mixer Configuration — The Wing-Specific Step

Unlike a quad where the mixer is always “Quad X,” wings have configurations that map to physical control surfaces:

For a flying wing, INAV’s “Flying Wing” mixer preset handles elevon mixing automatically — no CLI commands needed. Set it in the Configuration tab, save, and verify control surface directions in the Outputs tab before ever applying throttle.

Auto-Launch: The Feature That Makes Wings Practical for FPV

Launching a wing in FPV goggles is dangerous without auto-launch — you can’t see the aircraft, and a bad hand toss at the wrong angle puts it in the dirt. INAV’s auto-launch handles detection, climb-out, and transition:

Configuration (CLI):

set nav_fw_launch_accel = 1500    # Launch detection threshold (mG)
set nav_fw_launch_detect_time = 40  # ms to confirm launch
set nav_fw_launch_thr = 1850      # Launch throttle (μs)
set nav_fw_launch_motor_delay = 500  # ms before motor spins
set nav_fw_launch_timeout = 10000    # ms before abort
set nav_fw_launch_climb_angle = 25   # degrees climb angle

Procedure:
1. Arm the aircraft on the ground. Motor will idle at zero throttle.
2. Toss the wing firmly — level or slightly nose-up.
3. INAV detects the acceleration spike, spins up the motor to launch throttle, and climbs at the configured angle for 3 seconds.
4. After climb-out, control returns to your sticks automatically.

The 500ms motor delay is critical — it prevents the prop from spinning while your hand is still near it during the toss. Do not reduce this value. A prop strike to your hand at launch power sends you to the ER.

Flight Modes for Fixed Wing

Map these to a 3-position switch and a momentary switch. My standard setup: 3-pos for MANUAL / ACRO / ANGLE, and a separate 2-pos for NAV ALTHOLD / NAV POSHOLD with RTH on a momentary switch for emergencies. This gives you access to the stabilization modes you fly with regularly without accidentally triggering autonomous navigation mid-flight.

Parameter Comparison: Quad vs Wing Settings

Common Mistakes & What Most Pilots Get Wrong

Mistake 1: Using Betaflight on a wing. Betaflight technically supports fixed wing via custom mixes, but it lacks navigation features, autonomous flight modes, and proper stall-speed awareness. If you want RTH, waypoints, or auto-launch — which you do — use INAV or ArduPilot. Betaflight-on-a-wing is for line-of-sight park flyers, not FPV.

Mistake 2: Skipping the compass calibration. Unlike a quad that can infer heading from GPS course-over-ground while moving, a wing in a headwind or loiter needs magnetic heading. Without a calibrated compass, NAV POSHOLD becomes toilet-bowling, and RTH may fly the wrong direction for the first 100 meters while GPS data catches up. Calibrate the compass outside, away from metal and power lines, and verify heading in the OSD matches reality before flying beyond visual range.

Mistake 3: Auto-launch throttle too high for the airframe. A 1850μs throttle value on a high-KV motor with a small, fast prop works. The same value on a low-KV motor with a 10-inch prop will torque-roll the wing into the ground on launch. Start at 1750 and increment up by 25 until you get a clean launch without roll. I destroyed a 1.2m ZOHD wing on the first launch because 1900μs of throttle on a 9-inch prop rolled it inverted before it reached 5 meters of altitude.

Mistake 4: Configuring RTH altitude too low for terrain. INAV’s default RTH climb altitude is 40 meters, which is fine in flat terrain but useless in mountains. If your flying site has 60-meter hills between you and home, set RTH altitude to at least 100 meters above launch altitude. The aircraft climbs to RTH altitude before heading home — if that altitude intersects terrain, it won’t make it.

Mistake 5: Forgetting to set failsafe modes in the receiver. ELRS and Crossfire receivers have their own failsafe settings that determine what the flight controller sees when signal is lost. Set the receiver failsafe to “No Pulses” (not “Hold Last Position”), then configure INAV’s failsafe to trigger RTH after 1 second of signal loss. If the receiver holds last position, INAV never knows signal was lost and your wing flies away on its last heading until the battery dies.

⚠️ Regulatory Notice: Fixed wing FPV operations, particularly beyond visual line of sight (BVLOS), are subject to specific 2026 regulations that differ significantly from multirotor rules. The FAA (US) requires a Part 107 waiver for BVLOS operations and mandates Remote ID compliance for aircraft over 250g. EASA (EU) Open Category rules limit fixed-wing operations to visual line of sight at maximum 120m altitude without specific authorization. The CAAC (China) prohibits all BVLOS civil UAS operations without a certified operator permit. Fixed wing aircraft operating under autonomous navigation (RTH, waypoint missions) may require separate operational authorization in most jurisdictions.

See Also

A reliable GPS setup is the foundation of fixed wing confidence. See our Betaflight GPS Rescue configuration guide for RTH fundamentals. For long-range flight planning, our long-range FPV flight planning guide covers waypoint strategies and battery management. And for the other side of autonomous flight, check out the INAV setup for fixed wing reference.

A clean wing build starts with a flight controller that doesn’t fight you. The Matek F405-WMN flight controller includes an integrated barometer, compass, current sensor, and 6 servo outputs on dedicated pins — it’s the standard for sub-1kg FPV wing builds and I’ve deployed six of them across my fleet with zero hardware failures.