If you’re new to FPV drones or RC models in general, you’ve probably come across the word “failsafe” and wondered what it means. In this tutorial, we’ll explain what failsafe is, why it’s important, what causes it, and how to set it up in Betaflight and EdgeTX radios. Failsafe is a safety feature in RC systems that activates when your receiver loses connection with your transmitter. Depending on your setup, selecting the correct failsafe behavior can prevent crashes, flyaways, or worse—losing your expensive drone.
It’s critical to configure failsafe properly to minimize damage and ensure your drone doesn’t fly away during a connection loss.
New to Betaflight? Check out my Betaflight beginner’s guide: https://oscarliang.com/betaflight-firmware-setup/
What Is Failsafe?
Failsafe refers to what your drone does when it loses connection with your radio controller.
Common causes of failsafe:
- Radio Signal Loss – Flying too far, obstacle blocking signal, or into areas with interference.
- Hardware or Connection Failure – Broken wires, damaged antennas, or malfunctioning receiver/transmitter.
When this happens, the flight controller detects the loss and enters “failsafe”.
What Happens During a Failsafe?
Your drone’s response to a failsafe depends on your configuration:
- It might cut throttle and disarm.
- Level out and land (if configured).
- Return to home using GPS Rescue (if GPS is available and set up correctly).
For most freestyle and racing FPV drones, the default action is to cut throttle and disarm—causing it to fall from the sky. While it may sound harsh, this might be safer than allowing an uncontrolled drone to stay in the air, which can potentially fly away, or worse, causing damages with spinning propellers.
How to Set Up Failsafe in Betaflight
Here’s how to check and configure failsafe in Betaflight:
- Connect your drone to computer via USB and open Betaflight Configurator.
- Go to the “Failsafe” Tab, here you can configure Failsafe.
- To apply the settings, click Save and Reboot.
Now, let me explain how failsafe works in Betaflight and what the settings mean.
Two-Stage Failsafe Explained
Betaflight uses a two-stage failsafe system for greater and more flexible control: Stage 1 and Stage 2.
Stage 1 (Channel Fallback)
Stage 1 failsafe is triggered immediately upon signal loss, you can configure how each channel behaves:
- Hold: Keeps last stick position (e.g. if the drone was ascending, holding throttle will make it keep climbing).
- Set: Goes to a predefined value (e.g. you can set throttle to its hover point).
- Auto:
- For throttle it simply drops to minimum which is 0.
- For pitch/roll/yaw, it centers the sticks which is 1500.
Stage 2 (Failsafe Procedure)
After a short period (by default 1.5 second), if the signal doesn’t restore, it enters Stage 2 failsafe, where Betaflight performs the selected failsafe procedure:
- Drop (default): The drone just disarms and falls to the ground.
- Land: Levels out and slowly descends.
- GPS Rescue: Attempts to fly back to launch point.
This two-step system offers great flexibility and safety, it can avoid unnecessary crashes from minor signal glitches, while minimizes the risk of flyaways from serious signal loss.
Default Failsafe Settings (Betaflight 4.5.2)
- Stage 1: Throttle to minimum, Roll/Pitch/Yaw centered.
- Stage 2: After 1.5 seconds of continued signal loss, the drone disarms, motors stop and it drops to the ground.
Configuring Stage 1
Whether you need to change the settings in Stage 1 depends on your specific needs. If the failsafe you’re experiencing is just a temporary signal dropout, properly configuring Stage 1 might give you a chance to regain control and recover without crashing (or going into Stage 2). By default, Betaflight waits 1.5 seconds before entering Stage 2—adjust this value if necessary.
For example, upon failsafe, you could activate Angle Mode, set the throttle to your drone’s hover point, and center all sticks so the drone levels out and hovers briefly, giving it time to regain signal. However, if you’re unsure what you’re doing, it’s best to leave these settings at the default (Auto).
Example of configuring Stage 1 Failsafe to level out and hover
AUX Channels are used to toggle arm/disarm, flight modes, or trigger features like a beeper. During Stage 1, AUX channels default to “Hold”, but you can set them to a specific value using “Set” if needed (e.g., force the beeper to activate, or enable Angle mode when failsafe kicks in).
Configuring Stage 2
For most beginners, the default behavior should be fine for the most part, avoid changing it unless you know what you are doing. If your drone has a GPS module, consider setting up GPS Rescue.
Do You Need to Set Failsafe in the Radio?
Usually not, if you’re using a modern radio link / protocol like ExpressLRS or Crossfire. The receiver automatically informs the flight controller when failsafe occurs, and Betaflight handles the rest. However, with older radio protocol like FrSky D8 or D16, you may need to configure failsafe mode in the transmitter (e.g. “No Pulses”, “Custom” or “Hold” under Internal RF settings). But if you’re using Betaflight and a modern receiver, you don’t need to worry about this.
If you’re using an ExpressLRS receiver with SBUS output, or PWM output without a flight controller, you can configure failsafe channel behavior in the ExpressLRS Web Interface (see the 3rd screenshot below), where you can define specific values for each channel.
How to Test Failsafe
If you are using “Drop” as your failsafe procedure, testing it is straightforward:
- Remove all propellers for safety.
- Plug in battery and arm the drone (motors spinning).
- Turn off radio.
- Observe what happens—the motors should stop spinning within a couple of seconds, indicating failsafe is working.
However, if you are using “Land” or “GPS Rescue” as your failsafe procedure, then you should test it by simulating a failsafe during flight (avoid turning off your radio during flight as it can be dangerous):
- Go to the Modes tab.
- Add the Failsafe mode and assign it to a switch.
- Test in a controlled area, keeping altitude low in case the drone drops to minimize damage.
- Flip the failsafe switch to test how your drone reacts.
Conclusion
Failsafe is one of the most important features to set up correctly when flying FPV. Even though losing control sounds scary, a well-configured failsafe can save your quad, prevent it from flying away uncontrollably and reduce the risk when losing control.
If you’re just starting, the default settings are a good starting point. But once you get into more complex applications such as long-range or GPS-based flying, take time to understand and tweak these settings to fit your environment and flying style.