I remember an 80s movie in which the hero was a used a helecoptor. He kept it hidden on/in a mountain. I cannot remember if he was a membr of the police force or military. If I am not mistaken it may have had a series modeled after it.

That sounds like Airwolf
Airwolf - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Airwolf)

At the same time there was Blue Thunder
Blue Thunder - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Blue_Thunder)