Although at the moment IATA is not recommending social distancing on board aircraft ( middle seat off) it is thinking about it : from their latest relaae :
Calls for social distancing measures on aircraft would fundamentally shift the economics of aviation by slashing the maximum load factor to 62%. That is well below the average industry breakeven load factor of 77%..With fewer seats to sell, unit costs would rise sharply. Compared to 2019, air fares would need to go up dramatically—between 43% and 54% depending on the region—just to break even.
But with current average load factors on international flights ( not domestic) in the 10-15% range they will have to do something more dramatic to get people back in aircraft ... masks, disinfectants and higher air recycling rates do not seem to be enough to have the desired effect..