I think if there were pilotless airplanes it might discourage would be hijackers to hijack and therefore resulting in safer airplanes but should also be justified for warfare too by lessening the amount of pilots that the military would otherwise have to risk for extremely dangerous missions and will make things safer.
I do not think that pilotless airplanes can be morally justified. If there is not pilot, the chances of making mistakes increases significantly. This would lead to more innocent people being killed. Even though the pilotless airplanes could have cameras to assist them, many times people are killed without even knowing who they are. This is immoral and unjust.