[Murph]

Just tried setting up a simple interception mission with HurriMIs v He111s- after returning to base, the tower refused to let the planes land (as player aircraft I asked for and got permission to land).
I'm a real newbie at mission building, any ideas why this might be? I wondered if it might be because I did'nt set the elevation of the field in the mission ( it's somewhat over 2000 ft elevation).
Can not having fields at sea level cause issues?