# How to Fix Betaflight Runaway Takeoff Prevention Error (Anti-Taz)
If you’ve just built a new FPV drone or replaced a flight controller, you might encounter the dreaded **Runaway Takeoff Prevention** error in Betaflight. Instead of hovering gracefully, your drone briefly twitches, disarms itself automatically, and drops to the ground.
This built-in safety feature (sometimes called “Anti-Taz”) is designed to prevent your quad from rocketing into the ceiling or causing injury when the PID loop goes out of control.
## Understanding the Symptoms
When Runaway Takeoff Prevention triggers, you will notice:
* The drone disarms immediately (usually within 1 second of arming and throttling up).
* The OSD (On-Screen Display) flashes a “RUNAWAY” warning.
* The motors might spin up aggressively for a fraction of a second before shutting down.
## Common Causes and Diagnostics
The root cause of a runaway takeoff is always the same: **Betaflight expects the drone to move in one direction, but the sensors detect movement in the opposite direction.** The flight controller tries to correct this by increasing motor speed, making the problem worse until the safety limit is hit.
Here is a quick reference table of the four most common culprits:
| Cause | Description | How to Verify |
| :— | :— | :— |
| **Props on Backwards** | CW props on CCW motors, or vice versa. | Check the pitch of the blade against motor rotation direction. |
| **Wrong Motor Direction** | Motors spinning outward when Betaflight expects “props in”, or vice-versa. | Use the Betaflight Motors tab (props off!) to check spin direction. |
| **Incorrect FC Orientation** | The flight controller arrow doesn’t point to the front of the quad. | Check the 3D model in the Betaflight Setup tab. Pitch/roll the quad by hand. |
| **Incorrect Motor Mapping** | Motor 1 is actually plugged into the Motor 3 pad, etc. | Spin up each motor individually in the Motors tab and match the numbering. |
## Step-by-Step Fixes
### 1. Verify Flight Controller Orientation
Before touching the motors, ensure your flight controller knows which way is “forward”.
1. Connect to Betaflight Configurator.
2. Go to the **Setup** tab.
3. Tilt your physical drone forward. The 3D model on screen should also tilt forward.
4. If it tilts backward or rolls instead, go to the **Configuration** tab and adjust the **Board and Sensor Alignment** (Yaw degrees usually need to be set to 90, 180, or 270).
*Pro Tip:* If you’re building a new rig and your current FC has a damaged gyro causing erratic behavior, consider upgrading to a reliable flight controller. We highly recommend the **[UAVModel F405 Stack / Flight Controller](https://uavmodel.com/)** for its robust gyro shielding and clean layout, making mapping and orientation a breeze.
### 2. Check Motor Mapping and Direction
Remove your propellers before doing this!
1. Go to the **Motors** tab.
2. Acknowledge the safety warning.
3. Use the motor sliders to spin **Motor 1** (bottom right). Ensure only the bottom right motor spins.
4. If the wrong motor spins, you need to remap your motors using the CLI `resource` command or the Betaflight motor reordering wizard.
5. Next, check the spin direction. If Betaflight expects “props in” (standard), Motor 1 should spin clockwise. If it spins counter-clockwise, you must reverse it in BLHeliSuite, Bluejay configurator, or the ESC software of your choice.
### 3. Double-Check Propeller Installation
This is the most common mistake for beginners. FPV props have a leading edge (thick) and a trailing edge (thin). Ensure the leading edge is biting into the air in the direction of motor rotation.
## Video Walkthrough
For a visual guide on resolving motor direction and mapping issues, check out this excellent explanation:
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By methodically checking your FC orientation, motor mapping, motor direction, and prop placement, you’ll clear the runaway takeoff error and get your drone safely into the air. Always test hover in an open space!