great answer GHG.
One nuance that is sometimes lost is that 1 carrier may not be able to potentially support 2 different planes, flying off in opposite directions.
If both planes do not have an alternate landing site,
and both would rely on the same carrier to recover them,
the fact that 1 plane or the other (or both) might die
doesn’t permit you to rely on that carrier,
if it would have to move to recover one of the planes in such a way that it could not then recover both.
If the carrier could stay where it is, or move and still recover both planes within 4 moves, the move is legal. If 1 plane dies, you must noncom move the carrier (if necessary) to receive the other. If both planes die, you can noncom move wherever you like.
The thing you cannot do is combat move 2 planes that both rely on the same carrier in such a way that the carrier could not possibly recover both. What actually occurs during combat doesn’t matter; the move must be legal as of the finalization of combat moves.