I recently got an iPhone x and i was thinking of using my iPhone 6s as my “drone phone” just wanted to know  if its a good idea or it will affect my flight, because of no data or anything, i fly in airplane mode anyways. Can i keep my iPhone x close with me during the flight without putting it in airplane mode? Just wanted to know how to handle this situation.

Thank you!

You don't need mobile data to fly your drone, but you need Wi-Fi because you will have to update the firmware.
Airplane mode? Maybe, I fly without airplane mode on and get no interference.

Sell the 6S and use the X