Honestly I tend to just cash it in to speed up an early rec tanks... but I could come up with a couple of other uses:
The ground attack penalty makes it... not great for killing native life, but the credits can be worth it.
As Petek mentioned, it's not actually limited to the range it can travel in one turn. I don't remember how much damage copter units take from forced landing - though my first bet would be 30% - but the next turn it'll somehow have scavenged up a full tank. You can uncover quite a lot of nearby tiles with one knowing that.
IIRC spotting other factions with a copter unit does not give diplomatic contact. This is probably bad rather than good, but it's something that's good to know.
If you're not above rule abuse, having an air unit around early makes life easier in a lot of ways. Use it to enter fungus tiles reliably without any risk of worm spawns, park it on top of a unit that you really don't want attacked this turn (or generally on a tile that you don't want any enemies to enter), use it to dodge ZOCs when you can't spare a probe team, etc.. Just be sure to have it end its turn with no moves left in that case, because the pilot might get cold feet and start flying home if you press space while the unit still has moves...