The gnome Dvorak looked up from the little compass he was tinkering with, before suddenly springing to life like a clockwork toy soldier.  "My crew can hold the airship more-or-less over the fort at an altitude of fifty feet, enough for you to descend by ropes if you're feeling brave.  We're not under contract for anything more than that, but according to your information, the orcs lack any means of effectively attacking my ship."  Dvorak said quickly, gesticulating wildly before settling down again to return to his compass.  He adjusted his ring of regeneration, nervously glancing around.  "We can also get up to about 11,500 feet."  The gnome mumbled, before getting back to his work.