At least some states require notification of local authorities before launching model rockets (such as California). Some states also put out altitude ceiling re

At least some states require notification of local authorities before launching model rockets (such as California). Some states also put out altitude ceiling regulations for them. When I lived outside Chicago in the first half of the 00's, you had to get approval for launching above 2500 ft. You were also required to cease launching if any low flying aircraft were visible. You could get in some real nasty trouble if you violated those rules.