Radio Failsafe unreliable

I am using a Spektrum DX8 with an AR500 receiver.
I set up the radio failsafe as described here: … e-failsafe

However, when I test it in stabilise it works fine for the first time, it says RTL which Is what I have set it to do.
If I test it in Loiter or RTL it says LAND then disarms after 5 seconds which would crash the quad.

Any ideas how I can get around this please?

How are you testing? In LAND mode, once it thinks you’ve landed, it does disarm. If you’re testing on the ground, that’s exactly what will happen.

I have the APM connected to the pc with a USB cable,
I am arming the APM in stabilise, going to 50% throttle then switching off the TX.
I have set it to RTL but it just goes to Land.
Please see the screenshot

As you can see the throttle PWM is dropping below the failsafe point but the APM is choosing Land instead of RTL

What does the HUD say when you turn off the Tx? I tested mine and it does say RC no signal (or something like that).

Yes, I get the same.

Have you read this - … -failsafe/

Clearly says if you go into radio failsafe while within 2mtr of the home point (ie where you armed it) then it will just go into land mode. Land mode auto disarms when it detects the uav has landed so what your seeing is correct and normal.

If you want to test it properly, you will need to arm it, then move 3mtr or preferably more then switch off the radio.

Looks like MarkM has it. I just went to test it myself and my quad just goes straight to Disarmed when I kill the Tx.

I think I’ll just try in in-flight :slight_smile:

Thanks Mark M,

It was indeed within 2m of home so just selected LAND.

I moved the HOME position further away and it worked fine.