I don't think you can use the
fire function on vehicles, only men...
At least I have never seen that you could choose a firemode in a vehicle...
which would be 'single', 'burst' or 'auto'...
You got the error probably because there's no firemode called Maverick...
I think you better use the the combination of doTarget and doFire...
And to get the plane to use Mavericks just remove all the other ammo and give it back afterwards...
Dunno if it works though...