Radio Failsafe "No Pulse" method, able to Disarm, but Flight Mode does not change after the disarming

I am a newbie in Traditional Helicopter. I just started to test the radio failsafe in Mission Planner on my Heli with Pixhawk 2.4.8 running 4.2.2 official firmware. My transmitter is OpenTX Radiomaster TX16S, and my receiver is a 8 channel Cooltec Futaba S-FHSS and S.Bus compatible receiver. I set up the receiver’s failsafe in my OpenTX Transmitter using “No Pulse” method. After I connected the heli to Mission Planner using USB cable, chose Stabilize Mode, bound the receiver, pressed the safety switch, armed the heli with the throttle low rudder right stick and set up the Radio Failsafe in Mission Planner with " Enabled Always RTL", and then turned off my transmitter. I can see the Mission Planner’s Failsafe Setting showed the heli became Disarmed, but to my surprise, the flight mode did not change from Stabilize to RTL or Land. I have seen other youtube videos on Frsky receiver with “no pulse” failsafe setting, their flight modes always changed after turned off the transmitters. I don’t know what else should I set to correct this problem.

Could someone please help me with this?


If I’m reading your situation correctly this is normal behavior for a multi-rotor in ArduCopter, so it’s likely helicopters are the same. If the drone is on the ground and armed it will only disarm. It will not change modes. You should see a message that says RC Failsafe.

Hi Allister,

Thanks for the answers. I did see the message RC Failsafe after the disarming. But I checked the youtube videos on this topic, their vehicles are on the ground and indoor, but their flight modes changed after the disarming.

Those are both pretty old videos so it’s very likely the code has changed since then.

Hi Allister,
From your experiences, have your vehicle ever RTL or landed after the Radio Failsafe events despite the testing on the ground that never changed the flight modes by these RC Failsafe events ?

Well, thankfully I’ve only ever had a couple of legitimate radio failsafes but in each case the drone went into RTL or Smart RTL as was setup in the configuration. My experience with quads (and planes) is the radio failsafe works as described in the link I posted above (or the plane equivalent). I do not know if Heli is different.