a fail safe is usually incorporated in your receiver, not your transmitter. When it is set up and there is a loss of signal the receiver will do several things to save you losing your model. Often it will put the model into a slow, wide, level turn and also cut the throttle. This will allow you to get control back. I know that some Spektrum receivers have this feature but not sure about others. Where I fly, it is not something that I would use as my distance vision cuts out before the reception of my model.