Throttle failsafe

Hi, I am testing my hexacopter (pixhawk 3.5 rc5) range. When my drone is about 450m far, it loses signal and returns back. But stragne thing is that it is always throttle (ch3) which drops down to 900us and all other channels are stable. Is it normal ?
I am using Turnigy 9x transmitter (with ER9x Firmware) and Turnigy 8ch receiver with PPM Encoder module v 1.6 from Ebay.

Thank you…

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2017-05-02 18-35-20.bin (3.7 MB)
2017-05-06 11-18-42.bin (2.5 MB)
2017-05-06 11-52-49.bin (3.2 MB)

Depending on how your receiver failsafe is set up, that is most likely normal behavior. Default failsafe settings are usually for Throttle (Ch3) to drop to 900us (ie. engine idle) and all other channels go to 1500us.

Again, it does depend on exactly what receiver model you have and what settings you’ve entered for the failsafe.