Blown ESCs & motor; how to (disarm) UAV, in case of emergency?



Is there a way to manually disarm the drone (e.g. pushing the RC’s throttle lever down & left) whilst running a script, such as for the (attached) basic takeoff & land mission? I tried this, i.e. “pushing the RC’s throttle lever down & left”, but it doesn’t work, at least for me …

I personally thought it was a little unsafe to not introduce any emergency safety measure (in the online course tutorial). But my local government local Transport Safety Bureau appears to agree, based on a recent incident (applicaple details highlighted in the attachments):

For this reason, I earlier practiced (for an emergency situation) pulling out the ESC cables from the flight controller’s servo rail while the motors are highy active (the battery is to hard to get to/unplug while the props are spinning). But this indirectly resulted in the blowing up of one of the ESCs, & damaging it’s motor.

I replaced the ESC, but not the motor (I didn’t know at the time that the motor was damaged), so the new ESC blew & actually caught fire …

Kind regards


Hello Ben

Never interact with a drone while it is running else risk losing a finger! Besides, the esc wire to the rail is only to provide backup power to the flight controller and does not power the motors.

Yes, there are several measures you can take.

First off, as described in the course, it is always a good idea to secure the drone to a weighted cord on initial flights.

Second, if you took the programming course, then you can also test flight missions in simulation prior to out in the field. I do this quite often as I rather find problems in the office first.

Third, I would refer you to flight modes you can program into a transmitter switch for emergencies as you describe. The Emergency Stop, Interlock and Brake modes will provide immediate control to stop the vehicle. Randy McKay demonstrates each of these modes in the accompanying link Youtube.

Fourth, you should definitely become familiar with using Failsafe. This can be set up in the receiver or/and with Mission Planner. I use this in all flights to initiate RTL mode whenever the copter loses signal from the transmitter. Even if I run a totally autonomous mission I am always ready to take manual control.

Finally, I would refer you to this blog on safe flying.

Happy flying!