There are at least two flight simulator applications that run under Linux i.e : X Plane and FlightGear which is a free and open source software.
FlightGear is available at Ubuntu repository and there's not installation method easier than this. Just fire up your Synaptic Package Manager and search for flightgear and there it is:

And 212 MB later, here it is :

oooops
It's quite big, about a third of Ubuntu live CD size, so prepare some snacks, in my case I let it ran overnight.
keyword : ubuntu, flight simulator
FlightGear is available at Ubuntu repository and there's not installation method easier than this. Just fire up your Synaptic Package Manager and search for flightgear and there it is:

And 212 MB later, here it is :

oooops
It's quite big, about a third of Ubuntu live CD size, so prepare some snacks, in my case I let it ran overnight.
keyword : ubuntu, flight simulator



I live 15 minutes from my ubuntu repository mirror (UmeƄ, Sweden) with a 100 Mbps connection. 212,000,000-byte download should be about 16.960 seconds (theoretical limit). :-D
:) nice, I wish I had that kind of connection. But if I had, I think my harddisk would be full in no time, downloading every applications in repository.