Van Sant Airport in Erwinna
Van Sant airport is a small but busy, grass strip airport in Erwinna PA. You can get biplane rides, glider lessons and try hot air ballooning. Or, you can just watch the planes taking off and landing.
The Van Sant Airport site has details on available rides. Note that there is a weight limit depending on the aircraft. The airport is a bit off the beaten path. If you come in from the south, you are right under planes taking off or landing.