# Betaflight GPS Rescue: Complete Setup, Testing, and Troubleshooting Guide
Losing video signal at 500 meters is terrifying. For years, the only option was to disarm and pray. Betaflight GPS Rescue changes that — it autonomously flies your quad back to the launch point using satellite positioning. This guide covers every setting, every test procedure, and every failure mode so you can trust GPS Rescue with your quad.
## How GPS Rescue Works
When triggered (either by failsafe or a dedicated switch), GPS Rescue takes control and executes three phases:
1. **Climb Phase**: The quad increases altitude to a safe minimum height above the launch point.
2. **Return Phase**: It flies toward home at a configurable speed, maintaining altitude.
3. **Descent Phase**: Once overhead, it descends at a controlled rate until you regain control or it disarms automatically.
## Hardware Requirements
| Component | Minimum | Recommended |
| — | — | — |
| GPS Module | BN-220 (M8030) | M10 chipset (BN-880Q, Flywoo GM10) |
| Magnetometer (Compass) | Not required | Recommended for heading accuracy |
| Flight Controller | F4 or newer | F7/H7 with dedicated UART for GPS |
| UART Connection | 1 free UART | UART with DMA for stable data |
| Firmware | Betaflight 4.3+ | Betaflight 4.5+ |
**Important**: GPS Rescue does NOT require a magnetometer in Betaflight 4.3+. The flight controller uses GPS course-over-ground data to determine heading once moving. A magnetometer helps with initial heading lock but is optional.
## Step-by-Step Configuration
### 1. GPS Hardware Setup
– Wire GPS TX → FC RX on a free UART.
– Wire GPS RX → FC TX (optional, for UBLOX protocol configuration).
– Enable the UART as “GPS” in the Ports tab.
– In the GPS tab, verify satellite count and 3D fix before proceeding.
### 2. Core GPS Rescue Settings
| Setting | Recommended Value | Explanation |
| — | — | — |
| Angle | 35-45 degrees | Climb/return tilt angle; 45 is aggressive |
| Initial Climb | 25-40 meters | Altitude added above home point |
| Ascent Rate | 5-8 m/s | Climb speed; lower = more stable |
| Return Speed | 8-12 m/s | Fast enough to beat wind, slow enough to stay stable |
| Descent Rate | 2-4 m/s | Controlled descent; do not exceed 5 m/s |
| Ground Speed Mode | ON (Normal) | Ensures consistent speed regardless of wind |
| Throttle Min | 1200-1250 | Minimum throttle during rescue |
| Throttle Max | 1750-1800 | Cap throttle to avoid excessive speed |
| Throttle Hover | 1350-1450 | Cruising throttle for level flight |
| Min Satellites | 7-8 | Below this, rescue will not activate |
| Allow Arming Without Fix | OFF | Forces GPS lock before arming |
| Sanity Checks | ON | Rescues that appear “crazy” trigger a landing instead |
| Use Compass | OFF (if no mag) | Set correctly for your hardware |
### 3. Stage 2 (Descent) Settings
These engage once the quad is within 50-100 meters of home:
| Setting | Value | Notes |
| — | — | — |
| Descent Distance | 50-100m | Reduce for tight landing zones |
| Target Landing Altitude | 5-10m | Disarm manually when low and close |
| Landing Altitude | 3m | Final altitude before disarm |
### 4. Failsafe Integration
Under **Failsafe** tab, Stage 2 must be set to **GPS Rescue** (not Drop or Land). Configure:
– Guard time: 1.0-2.0 seconds (delay before GPS Rescue engages to filter momentary dropouts)
– Failsafe throttle low delay: 0.5 seconds
## Testing GPS Rescue Safely
**Never trust GPS Rescue without testing.** Use this progressive validation method:
### Test 1: Bench Verification
Arm the quad (props off), switch to GPS Rescue mode via transmitter switch. In the GPS tab, verify the rescue indicator turns green and all sensors report valid data.
### Test 2: Line-of-Sight Low Altitude
– Fly 50 meters away at 8-10 meters altitude.
– Trigger GPS Rescue via switch (not by turning off transmitter).
– Be ready to override immediately if behavior looks wrong.
– Verify it climbs, turns toward home, and returns.
### Test 3: Line-of-Sight Higher Altitude
– Fly 100-150 meters away at 30+ meters altitude.
– Trigger rescue. Observe the full climb-return sequence.
– This validates wind-handling and speed settings.
### Test 4: Failsafe Simulation
– At safe altitude and distance, intentionally turn off your transmitter.
– Verify the quad enters failsafe, then GPS Rescue.
– Turn radio back on and regain control.
## Common GPS Rescue Failures
| Symptom | Cause | Fix |
| — | — | — |
| Rescue not activating | GPS satellites < minimum | Wait for 8+ sats; check GPS module placement |
| Quad spins during return | No mag + GPS heading drift | Enable mag or fly faster return speed |
| Rescue flies wrong direction | Home point not set on arm | Verify 3D fix before arming; wait for home arrow in OSD |
| Quad oscillates during return | PID tuning too aggressive for GPS flight | Use GPS Rescue-specific PIDs or reduce D gains |
| Barometer drift causes altitude error | Foam blocking baro; wind over baro hole | Cover baro with open-cell foam; avoid direct propwash |
| VTX overheating during rescue | 0 airspeed on descent means no cooling | Set pit mode on failsafe or reduce VTX power |
## Pre-Flight Checklist for GPS Rescue Pilots
1. GPS module has 8+ satellites and 3D fix before arming.
2. Home arrow appears in OSD after arming.
3. GPS Rescue mode switch works (verified in Receiver tab).
4. Stage 2 failsafe is set to GPS Rescue.
5. Battery is fully charged — rescue can take 30-60 seconds.
For reliable GPS modules with fast satellite acquisition, M10 chipsets are the current standard. Browse the GPS module selection at [uavmodel.com](https://uavmodel.com) for BN-880Q, Flywoo GM10, and other M10-based GPS units with integrated compass options.
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