In United States v. Causby, decided in 1946, the Supreme Court ruled that a landowner owns the “immediate reaches” of the airspace above their property and that repeated low-altitude government flights that destroy the land’s usefulness are a taking under the Fifth Amendment, requiring just compensation. The decision discarded the old common-law idea that private ownership extended all the way to the heavens, but it kept meaningful property rights in the airspace close to the ground. Nearly eighty years later, it is still the case courts reach for whenever the question is where private property ends and public airspace begins.
A Chicken Farm Under the Glide Path
Thomas Lee Causby and his wife owned a small home and chicken farm near a municipal airport outside Greensboro, North Carolina. During World War II, four-engine bombers and fighter planes began using the field heavily. The approved glide path for one runway crossed directly over the Causby property at 83 feet above the ground, clearing the house by 67 feet and passing just 18 feet above the tallest trees on the lot.1Justia U.S. Supreme Court Center. United States v. Causby, 328 U.S. 256 (1946)
Day and night, the noise and glare made the property nearly unlivable. Chickens panicked and threw themselves into the walls of their enclosures. Around 150 birds died that way, and the Causbys eventually abandoned the poultry business. They sued in the Court of Claims, arguing the government had effectively seized their property without paying for it. The Court of Claims agreed. The United States appealed.
Rejecting the Sky-to-Heavens Rule
For centuries, common law followed a Latin maxim usually translated as “whoever owns the soil owns everything up to the heavens.” Read literally, that rule would make every airline flight a trespass. Justice William O. Douglas, writing for the majority, dispatched the doctrine directly: it “has no place in the modern world.”1Justia U.S. Supreme Court Center. United States v. Causby, 328 U.S. 256 (1946)
That mattered because Congress had already declared, through federal aviation statutes, that navigable airspace belongs to the public. Today that principle is codified in a statute providing that the United States has exclusive sovereignty over its airspace and that citizens have a “public right of transit through the navigable airspace.”2Office of the Law Revision Counsel. 49 USC 40103 – Sovereignty and Use of Airspace Federal regulations set the floors for that navigable zone: 1,000 feet over congested areas and 500 feet over open land.3eCFR. 14 CFR 91.119 – Minimum Safe Altitudes: General The military planes at 83 feet were nowhere near those floors. The government’s “public highway” defense could not reach them.
The Immediate Reaches Standard
The heart of the opinion is the test Douglas built to replace the old rule. A landowner, he wrote, “owns at least as much of the space above the ground as he can occupy or use in connection with the land.” Think of the airspace just above rooftops, trees, and fences. Douglas compared it to the gap between buildings that lets in light and air: you do not fill that space physically, but the property is not usable without it.1Justia U.S. Supreme Court Center. United States v. Causby, 328 U.S. 256 (1946)
High-altitude flights pass through harmless air and generate no claim. The picture changes when flights sit low enough, and repeat often enough, to interfere directly with what the owner does on the ground. Douglas offered an analogy: an elevated railway running at the same altitude as the planes would obviously take part of the property, even if no support column touched the soil. Persistent low overflights do the same work.
The standard does not turn on a single dramatic incident. It asks whether the government’s use of the low airspace is so continuous and disruptive that it effectively strips the owner of the land’s value. A one-time flyover is not enough. Regular flights that render a farm, home, or business unusable are. That distinction is where most modern overflight fights are won or lost.
A Taking Without Setting Foot on the Land
The Fifth Amendment forbids the government from taking private property for public use “without just compensation.”4Constitution Annotated. Amdt5.10.1 Overview of Takings Clause The United States never entered the Causby farm, built anything on it, or formally condemned it. The Court held that none of that mattered. Flights so low and so frequent that they destroyed the property’s usefulness “are as much an appropriation of the use of the land as a more conventional entry upon it.”1Justia U.S. Supreme Court Center. United States v. Causby, 328 U.S. 256 (1946)
What the government had taken, the Court said, was a flight easement: a legal right to pass over the land for a specific purpose. Not the whole farm. Just the right to run military aircraft through the airspace above it. Compensation would reflect the drop in market value that easement caused. The principle is simple. When the government effectively occupies your airspace in a way that guts your property’s value, it owes you money, even if no one physically steps on your land.
The Dissent
Justice Hugo Black dissented alone; Justice Robert Jackson took no part. Black argued that what the Causbys suffered was, at worst, a tort claim for nuisance or negligence, not a constitutional taking. Expanding “taking” to cover overflights, he wrote, gave the word a meaning it “has heretofore never been given.”5Supreme Court of the United States. United States v. Causby, 328 U.S. 256 (1946) His deeper concern was practical: Congress, not the courts, should sort out the problems created by aviation, and locking the answer into the Constitution would invite endless litigation every time an airport expanded. The majority disagreed, and the Causby framework has governed overflight cases ever since.
Who Pays: Griggs v. Allegheny County
Causby involved the federal government and military planes. A natural follow-up: what happens when a local government runs a civilian airport and its approved flight paths cross private homes? The Supreme Court answered in Griggs v. Allegheny County in 1962.
A homeowner near the Greater Pittsburgh Airport faced conditions similar to the Causbys’. The Court held that the county, as owner and operator of the airport, was the entity responsible for the taking, not the federal government. The county chose the site, designed the runways, and decided which flight paths would be used. If those paths crossed private land at low altitude, the county needed to acquire the necessary easements, just as it would need to acquire land for a road. It had not acquired enough property when it built the airport.6Supreme Court of the United States. Griggs v. Allegheny County, 369 U.S. 84 (1962) Together, Causby and Griggs mean either the federal government or a local airport authority can owe compensation, depending on who controls the flights.
What Causby Means for Drones
The Causby framework was designed for manned aircraft over farms. Whether it applies with equal force to a small drone hovering over a backyard is one of the more actively debated questions in current aviation law.
Under FAA rules, commercial drone operators flying under Part 107 cannot exceed 400 feet above ground level.7eCFR. 14 CFR 107.51 – Operating Limitations for Small Unmanned Aircraft That ceiling sits below the 500-foot minimum safe altitude for manned flight over open land, which puts drones, by design, in the zone Causby called the “immediate reaches.” A manned plane at 500 feet is generally in navigable airspace and triggers no taking. A drone at 200 feet is in territory the 1946 opinion did not specifically address.
Federal law gives the FAA exclusive authority over aviation safety and the efficient use of airspace, which limits what states and cities can do. The FAA has indicated that local laws creating aerial highways, mandating geofencing, or imposing pilot licensing are likely preempted. State and local rules on privacy, trespass, and criminal misuse of drones at lower altitudes are generally not preempted, provided they stop short of a jurisdiction-wide ban on drone operations.8Federal Aviation Administration. Recreational Flyers and Community-Based Organizations No federal court has squarely resolved whether persistent neighbor drone flights over a yard are a taking under Causby, a state-law trespass, or something in between. Until Congress or the Supreme Court says more, the boundaries of property rights in drone-altitude airspace stay uncertain, governed by an opinion written for a world of propeller-driven bombers.
Bringing an Inverse Condemnation Claim
If government flights have destroyed the use of your property, the legal vehicle for seeking payment is called inverse condemnation. Standard condemnation runs the other way: the government files first and pays upfront. Inverse condemnation flips that; you sue after the government has already taken your property rights without going through formal channels.
Claims against the federal government go to the U.S. Court of Federal Claims, which has jurisdiction over suits founded on the Constitution, including Fifth Amendment takings.9Office of the Law Revision Counsel. 28 USC 1491 – Claims Against United States Generally You have six years from the date the claim first accrues to file. After six years, the claim is barred.10Office of the Law Revision Counsel. 28 USC 2501 – Time for Filing Suit Pinning down when that clock actually starts can be difficult. It may run from when flights first became regular enough to be a permanent interference, from when property value first measurably dropped, or from when it became clear the flights were not going to stop.
Claims against a local airport authority follow a different route, usually in state court under state inverse condemnation or eminent domain statutes. Deadlines and procedures vary. Whichever government is on the other side, the core question remains the one Douglas framed in 1946: whether the flights are so low and so frequent that they amount to a direct interference with your use of the land below.