Soaring Over NH Soaring at Franconia
It turns out that Franconia Notch and the area near Mt Washington are considered to be some of the best places to fly gliders (sailplanes) east of the Rocky Mountains in Colorado and there is a club called the Franconia Soaring Association that operates gliders out of a 2,500 ft grass air strip beneath Cannon Mountain and Kinsman Ridge.
I've always believed that glider pilots stay airborne by climbing on thermals or columns of hot air that are rising faster than the surrounding colder air. But, I've also discovered that gliders use two other kinds of rising air called ridge lift and mountain waves. This makes a lot of sense when you consider the topology of Franconia Notch and Mt. Washington.
Ridge lift occurs when a stream of air hits a ridge or cliff face. The air is forced upward and a glider pilot can gain altitude by flying over or along it. Mountain waves operate on the same principle. Air hits one side of the mountain and flows over it. Here, a glider pilot can catch the wave at the base of the mountain and ride up it's slope gaining significant altitude and energy in the process.