Then put something in between, its not impossible. Just don't use passengers as armour.
Peter, you are right in that that's one of the most mentioned disadvantages of open rotors. I wonder if its a bit opportunistic reasoning though. For 100 years hundreds of aircraft design were developed, build and operated that way, thousands are flying around.
Is the TP400 illegal / useless? Or the Q400, ATR-72, An-70, DC7 or Conny?
f the prop is a little stronger then the ATR and the skin a bit stronger too, is there a problem?