That's a very nice game. I'm a retired Mozambican Merchant Marine Captain and all of this is very interesting for me. I have some suggestions to make;
a) The possibility to chose from two Levels/Modes. Beginner and Expert, were the Expert mode is pretty much as it is now with no geographic / navigational aids, and the Beginner Mode, equipped with Nav. Aids such as the name of the county, ocean, sea, lake, river and other well known land mark's like Mountains (e.g. Everest, Kilimanjaro...), Vulcans etc.. highlighted when the plane is flying through the respective aerial space as well as a Live World Map (Planisphere) North oriented with plane position on real time.
b) One control to open while is pressed a window with a very high birds eye view from the globe beneath the plane just to give a clue were on the globe the plane is.
Looking forward to help perfecting this very didactic game,
Thank you.