The Betaflight setup guide is blunt about the risk: it "puts extreme stress on motors and ESCs when the motors are obstructed after a crash." On a flat field it saves a walk. If a prop is buried in long grass or tangled in a branch, it is a good way to cook an ESC.
What it needs
- DShot. Turtle mode works by telling the ESCs to reverse spin direction, and that command only exists in DShot. The Modes docs list it as "DShot required". Oscar Liang points out that PWM, Oneshot and Multishot cannot do it, and neither can brushed whoops. In the Motors tab, DShot300 or DShot600 is the normal choice.
- ESC firmware that handles the reverse command. Betaflight's ESC firmware page notes that BLHeli_S only gained turtle mode in its last official release, 16.7, and recommends flashing Bluejay instead.
- A working accelerometer if you want the 2025.12 behaviour. The automatic motor stop and the OSD direction arrow both depend on it. Check that the model in the Setup tab follows the quad when you tilt it.
Switch, arm angle and OSD arrow
Put FLIP OVER AFTER CRASH on its own switch in the Modes tab, away from your arm switch. Oscar Liang's guide uses a spare channel such as AUX4. A two-position switch you will not bump in flight is the usual choice.
Many guides, Oscar Liang's included, tell you to set Maximum Arm Angle to 180° so the quad can arm upside down. Check what current firmware actually does first. In Betaflight 4.5, 2025.12 and 2026.6, the arming code skips the angle check whenever the crash flip switch is active (in the 2026.6 core.c: if (!isUpright() && !IS_RC_MODE_ACTIVE(BOXCRASHFLIP))). The default small_angle of 25° therefore does not block a turtle arm. A value of 180 makes the quad arm at any angle in normal mode too, which the Betaflight CLI reference marks as "not recommended". If your quad refuses to arm upside down with the switch on, find the arming-disable flag that is actually blocking it before you raise the limit. The same code also skips the GPS Rescue "no fix" arming block while the switch is on, so a missing satellite count will not stop you either.
In the OSD tab, enable the flip arrow (Oscar Liang lists it as Flip After Crash Arrow; the CLI position is osd_flip_arrow_pos). It shows only while turtle mode is active. The PR that added the new behaviour explains the point of it: if you push the stick the way the arrow points, you are most likely driving the motors that are free to spin, not the ones pressed into the ground.
How the sticks drive the motors
The stick logic surprises people who expect throttle to do something. From PR #13905 and the mixer code:
- Throttle is ignored. Only roll, pitch and yaw matter.
- The first 15% of stick travel is a deadband.
- Roll or pitch drives one pair of motors on that side. Yaw drives a diagonal pair. A diagonal stick move drives the single motor on that corner.
- Since 2025.12 the response is linear. About 50% stick gives about 50% drive to the pair. The old
crashflip_exposetting (35 by default in 4.5) is gone, because it made small inputs do nothing and then produced a sudden, often double, flip.
The PR's advice is to move the stick steadily toward full over about half a second to one second, in the direction of the arrow. Quick stabs send the motors to full power sooner.
crashflip_rate: the setting that changes behaviour
crashflip_rate is the maximum rotation rate in tens of degrees per second (15 means 150 deg/s). The default is 0, which turns all of the new attenuation off and gives you the old behaviour. With a non-zero value:
- Motor power fades as the gyro rate approaches the limit, which reduces over-rotation. This part works even without an accelerometer.
- With the accelerometer working, power also fades to zero as the quad turns about 90° from where it started. Once it is upright, the motors stay off. Momentum usually finishes the flip.
Starting values from the PR author:
| Quad | crashflip_rate |
|---|---|
| Typical race quad that over-flips a lot | 15 |
| Freestyle quad that sometimes over-flips | 25-30 |
| Whoop that occasionally double-flips but sometimes struggles to flip at all | 100 or higher |
| Whoop or other low-power build that rarely or never double-flips | 0 |
Oscar Liang reports that about 15 has worked for him on almost everything from tiny whoops to 5-inch quads. In the CLI:
set crashflip_rate = 15
save
You can also change it in the OSD menu under Misc (Crash Flip Rate). The Betaflight code marks that menu item as reboot-required, so it takes effect after save and reboot.
Two things to keep in mind. If the quad half-flips and settles more than about 90° away from its starting attitude, the motors will not spin again until you disarm and re-arm with the turtle switch still on, which resets the starting angle. And if you are stuck in a tree, the auto-stop can work against you. Both the PR and Oscar Liang suggest temporarily setting crashflip_rate to 0 so motor output follows the stick directly.
Do not confuse this with crashflip_motor_percent. The PR author describes it as a way to give some power to all four motors so a weak whoop can "leap up" off the floor, and says it is "NOT a command to use on full size quads".
Getting back into the air: manual or auto-rearm
What happens when you flip the turtle switch back depends on crashflip_auto_rearm, added in PR #14734. It defaults to OFF on standard builds.
- OFF (default). Turning the turtle switch off while armed disarms the quad, and Betaflight blocks arming until you toggle the arm switch yourself. Then you arm normally and take off.
- ON. Turning the turtle switch off while the arm switch is still on sets the motors back to normal direction and leaves the quad armed, ready to take off. The PR description mentions extra conditions (a successful flip, a non-zero
crashflip_rate), but the 2026.6 code that handles the switch simply restores motor direction and stays armed. Treat ON as "live the moment the turtle switch goes down".
Oscar Liang's view is that racers may want auto-rearm to save time, and casual pilots should leave it off and re-arm by hand. That matches the risk: with auto-rearm on, the turtle switch is the last thing between you and spinning props.
A sensible routine after a crash
- Disarm. Look through the goggles and listen. If a prop sounds blocked or is buried in grass, walk.
- Turn on the turtle switch, then arm.
- Push roll or pitch smoothly toward the OSD arrow. Give up after a few short attempts rather than holding full stick on a motor that is not turning. With bidirectional DShot, the Motor Diagnostics OSD element shows an "S" for a stalled motor, which tells you when to stop.
- With
crashflip_rateset, the motors stop when it lands upright. Turn the turtle switch off and then, depending on auto-rearm, either take off or cycle the arm switch.
Try it once on the bench first, upright and with the props off, so you learn which stick direction spins which corner before you need it in a field.