I know it was brought up some time in the past as the FAA information is unclear, depending on where you looked. The FAA requires that you _notify_ an airport when flying within 5 miles. They also mention that an agreement needs to be made. Others have read this as they need to approve of the flight. Here is the information directly from the FAA: Unmanned Aircraft Systems (UAS) Frequently Asked Questions/Help Can an airport operator object to model aircraft flights near an airport? Yes, an airport operator can object to the proposed use of a model aircraft within five miles of an airport if the proposed activity would endanger the safety of the airspace. However, the airport operator cannot prohibit or prevent the model aircraft operator from operating within five miles of the airport. Unsafe flying in spite of the objection of an airport operator may be evidence that the operator was endangering the safety of the National Airspace System. Additionally, the UAS operator must comply with any applicable airspace requirements. I can see where someone may want to fly at 10' 4.9 miles away from an airport and the person at the tower may just want to say no to day no. I can see that this should not endanger any manned aircraft. or perhaps you can't reach anyone and need to leave a message. So you _don't_ need permission (only need to notify) but you are still held the the safe flight requirement.