Turnigy 9x8c (and copies like my FlySky) reciver haven't internal failsafe with PPM recivers.
Original scheme here
When link between traismitter and reciver lost, on reciver outputs control values freeze, and rc model can fly away.
For fix that this scheme maked.
On link lost 555 timer will begin generate failsafe ppm code and mux switch signal source from reciver to 555's out.
CH-IN - reciver output
IN - 5th EEPROM pin (connected to reciver's LED)
OUT - to fly controller input.
Power supply - bypass from fly controller to reciver.
P.S. I used 74HC157 because not found something else in home:)
P.P.S. FlySky FS-R9B + Naza m-lite