why not rotorcraft?
I think the term "aircraft" is used for ANYTHING that flies around, including balloons, etc. Therefore airplane or aeroplane (either one?) can be used for fixed wing aircraft.
language is a strange thing
Westy
P.S. in German:
aircraft = Luftfahrzeug
airplane = Flugzeug
helicopter = either Hubschrauber, Helikopter or "Drehflügler"