Alright while waiting for your guide I've grown a synapse here.
Here is an easy way to get the Airborne Mountaineer Achievement Airborne Mountaineer - 25G - Why Climb A Mountain When You Can Fly To The Top.
Plane icon is where you'd want to go & land your plane then Airborne Mountaineer Achievement is all yours! LOL!
photo credits to my posse, R2D2