Does this include all planes or only attack planes?
Personally, I find spotter planes could be used as a simple "guns get +x accuracy at distances over y km", indicating them spotting the shell splashes closer to the ship, zero ability to attack themselves and maybe a way to extend the ships actual spotting range. I don't think even those should be implemented right now, though, arguably could at least be considered earlier than full on attack planes (if those come into play at all)