There are available in-line fail safe units which are primarily used for the throttle servo to shut the engine down or off in the event of a signal loss.

At least the JR radios with the 2.4gHz and PCM receivers also have more robust fail safe capabilities, that sets the receiver to adjust all of it's outputs to a pre-set state if the signal is lost.

After I've flown my plane a few times and am satisfied with the trims, I typically rebind the receiver to set the failsafe.

When I do so, I set the plane to have a VERY slight roll, high idle throttle, a touch of adverse rudder, and a bit of up elevator.

My thinking is that if the plane is out of reception range and heading away, the failsafe will kick in to slowly bring the plane back around, in the hopes of recapturing the signal.

The roll tends to bring the nose down, the slight elevator up tends to prevent this, and the slight adverse yaw will hopefully keep the plane from nosing into the ground due to the sustained roll.

That's what I've come up with, though fortunately I've never had to use it.

I'm open to other suggestions.