Ok as the topic suggests.
Im new to mapping and trying to create my very first map at the moment but i cant get an aeroplane to fly overhead can anyone point me in the right direction please?

The planes that fly overhead in maps are small models inside the 3d skybox. Before trying to do it you need to know about 3d skyboxes.

This is the valve developer tutorial: http://developer.valvesoftware.com/wiki/3d_skybox

But there are slightly easier to follow ones around if you look.

I'm not sure about tutorials on making the bombers fly, but its a series of path_track entities with a func_tracktrain linked to them and a prop_dynamic parented to the func_tracktrain. Certain path_tracks can be used to change the planes course, make the flyover sound, etc.

The best way to learn about it is probably to decompile an official map using VMEX and have a look at the 3d skybox.

*heres another: http://www.snarkpit.net/editing.php?page=tutorials&game=HL2&id=108

Hmm ok thanks mate ill have a play with that