Each National Forest has its own rules based on the forest usage, wilderness areas, trailheads, etc. For instance, in the Green Mountains National Forest, flights are unregulated as long as your not in a wilderness area or other specifically protected area such as the Appalachian Trail. In the White Mountains, many additional areas are restricted, within a certain distance of all trails, trailheads, roadside waysides, the Kancamagus Highway, areas along Bear Notch Road, etc. It is best to contact the main ranger station for each National Forest you are planning on visiting and see what there individual rules and restrictions are.