328 U.S. 256 (U.S. Supreme Court 1946)
United States v. Causby is the seminal Supreme Court decision that reconciled modern aviation with traditional property rights by recognizing that landowners retain protected interests in the "immediate reaches" of the airspace above their land.
Do frequent, low-altitude military overflights directly above private land, which substantially interfere with the landowner's use and enjoyment, constitute a taking of property under the Fifth Amendment requiring just compensation, even though the government does not physically occupy the surface and does not own the airport?
A landowner owns at least the immediate reaches of the airspace above the land that the owner can occupy or use in connection with the land. While the public has a right of transit in navigable airspace placed in the public domain by Congress, flights that are so low and so frequent as to have a direct and immediate interference with the use and enjoyment of the land effect a taking of an avigation easement requiring just compensation under the Fifth Amendment. Government liability for such a taking does not depend on owning the airport or the surface but on the imposition of a servitude in the airspace.
Yes. The government's frequent, low-altitude flights directly over the Causbys' property effected a taking of an easement in the immediate reaches of the airspace, requiring just compensation.
Causby is the cornerstone of aerial takings jurisprudence. It: (1) modernizes property law by limiting ad coelum while preserving landowners' control over the airspace they can practically use; (2) establishes that recurring, low-altitude overflights can be a per se taking of an avigation easement; (3) clarifies that takings liability does not require physical occupation of the surface or government ownership of the facility; and (4) sets the template for later cases, such as Griggs v. Allegheny County, on airport approach paths, and informs contemporary debates over drones and low-altitude operations. For law students, it is essential for understanding how the Takings Clause applies to intangible or non-traditional invasions and how statutory definitions (like "navigable airspace") intersect with constitutional protections.