As the popularity of drone use continues to increase, it directly impacts the privacy and safety of those at the ground level. In a recent case, Boggs v. Merideth, a drone operator sued his neighbor for shooting down his drone. As a result, several issues pertaining to the boundaries of “navigable airspace” and how that airspace interacts with the state property rights of landowners may be clarified.
The federal government has exclusive sovereignty of U.S. airspace. Congress delegated to the FAA the ability to define “navigable airspace” and the authority to regulate “navigable airspace” of aircraft by regulation or order. 49 U.S.C. § 40103(b)(1). While it is clear that navigable airspace falls under the purview of the FAA, the boundaries of that airspace remain unclear.
According to Federal Aviation Regulations, “navigable airspace” is defined as “airspace at and above the minimum flight altitudes prescribed by or under this chapter, including airspace needed for safe takeoff and landing.” 14 C.F.R. § 1.1. For airplanes, the minimum flight altitude while flying over congested areas or open air assemblies of persons is 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet. 14 C.F.R. § 91.119(b).
Over uncongested areas, airplanes can operate at an altitude of 500 feet above the surface. However, airplanes can operate even lower when over “open water or sparsely populated areas.” When flying over those areas, aircraft may not operate closer than 500 feet to any person, vehicle, or structure provided that if the airplane’s engines fail, an emergency landing will not create an undue hazard. 14 C.F.R. § 91.119(a) and (c). Two exceptions exist for when a person may operate an aircraft below these altitudes: (1) when necessary for takeoff or landing; or (2) in an in-flight emergency requiring immediate action. 14 C.F.R. § 91.119(a); 14 C.F.R. § 91.3(b). 
In United States v. Causby, the Supreme Court of the United States in 1946 provided guidance on where private property rights of airspace end and navigable airspace begins. In Causby, a farmer lived adjacent to a military airport where aircraft flew as low as 83 feet over the farmer’s property. As a result, the noise from the aircraft startled the farmer’s chickens, causing them to kill themselves by flying into walls.
Since the navigable airspace which Congress had placed in the public domain was airspace above what was deemed the minimum safe altitude (“MSA”), the Supreme Court reasoned that airspace above the MSA was immune from suits against the government for a takings violation.
The Causby Court put forth two key principles regarding airspace below the MSA. First, landowners have “exclusive control of the immediate reaches of the enveloping atmosphere.” Second, landowners own at least as much of the space above the ground as they can occupy or use in connection with the land.
While it appears that the lowest “navigable airspace” could descend to is just over the Causby limits, the circumstances of the case may limit its applicability. Causby took place during World War II. It involved large military aircraft flying 83 feet above the farmer’s property. The unsettling noise resulted in the destruction of the use of the property as a commercial chicken farm and caused the farmer’s family severe anxiety from the lack of sleep. In contrast, drones are typically not noisy or earsplitting, and often fly well below 83 feet. Further, drone technology did not exist when Causby was decided 70 years ago.
The Court ruled in favor of the farmer. However, several questions linger including “where the precise boundaries of public airspace above the farm meet the immediate reaches of the farmer’s property” and how high state government’s rights extend. 
In other words, would the Court in Causby have ruled in favor of the farmer if the aircraft at issue operated above 90 feet or perhaps 150 feet? The Causby decision does not clarify what happens between 83 feet and 500 feet. Moreover, it is unclear if the Court would have found a taking if the property was vacant and the aircraft caused no damage to the farmer or his property.
The FAA has divided airspace into different categories based on altitude. Class G airspace is defined from the Causby limits to 500 feet and is considered uncontrolled airspace. This begs the question, does “navigable airspace” include class G airspace and if not, does the FAA have the authority to regulate the airspace below?
The FAA argues that it “has authority to regulate aircraft in U.S. Airspace” at any altitude because Federal law states that the FAA “shall develop plans and policy for the use of the navigable airspace and assign by regulation or order the use of the airspace necessary to ensure the safety of aircraft and the efficient use of airspace. 49 U.S.C. § 40103(b)(1).
Furthermore, it could be argued that the FAA can regulate airspace below 500 feet despite jurisdictional limitations because another federal law gives the FAA the authority to prescribe “regulations and minimum standards for other practices, methods and procedure the [FAA] finds necessary for safety in air commerce and national security.” 49 U.S.C. § 44701(a). Under this section, the FAA regulates amateur rockets, motorized paragliders, and other vehicles below 500 feet.
Even if navigable airspace does not extend to the surface, the FAA has argued that it may regulate below navigable airspace because it can prescribe regulations “on the flight of aircraft for navigating, protecting, and identifying aircraft” and “protecting individuals and property on the ground.” 49 U.S.C. § 40103(b)(2).
As a result of increased drone technology and use, it could be that “navigable airspace” extends to the surface. At the moment, the area below “navigable airspace” is a gray jurisdictional area for the FAA to attempt to regulate and states continue to argue that they should be able to regulate flight below 500 feet through their traditional police powers. Boggs v. Merideth may provide answers to whether a drone flying below 500 feet is operating in “navigable airspace.”
As the case progresses, we will continue to monitor and provide updates of any developments.
 Minimum safe altitudes for helicopters differ from other aircraft. Specifically, “If the operation is conducted without hazard to persons or property on the surface . . . . A helicopter may be operated at less than the minimums prescribed [for fixed wing aircraft], provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA.” 14 C.F.R. § 91.119(d)(1).
 Jonathan Rupprecht, Drones: Their Many Civilian Uses and the U.S. Laws Surrounding Them, at 24-25, (Version 2.03) (2015).