United States vs. Causby

Low-altitude flights that directly and substantially interfere with the use and enjoyment of private land constitute a "taking" of an aerial easement under the Fifth Amendment, entitling the landowner to just compensation.

• Historically, common law recognized unlimited vertical ownership (cujus est solum ejus usque ad coelum).
• The advent of aviation made this rule impractical, as aircraft required use of airspace above private land.
• Congress enacted the Air Commerce Act of 1926, establishing federal control over navigable airspace and setting minimum flight altitudes (500 feet in rural areas, 1,000 feet in cities).
• The Causbys’ property was near a military airport used intensively during WWII. Flights followed a glide path that brought planes extremely low over their land.

• Filed in the U.S. Court of Claims (takings claim against the Federal Government).
• Court of Claims ruled in favor of Causby, finding a compensable taking.
• The U.S. Supreme Court granted certiorari.

• Plaintiffs (Causbys) owned a chicken farm near a military airport in Greensboro, NC.
• The north-south runway was ~2,200 feet from their home; a 100-foot-wide glide path passed directly over their property.
• Military aircraft (single and multi-engine) flew as low as 83 feet above ground, 67 feet above their barn, and 18 feet above trees on their land.
• Flights were frequent (4% of all flights used this runway from 1942–1946), day and night.
• Effects:
  • Noise deprived the family of sleep and caused fear.
  • Chickens panicked, refused to lay eggs, and ~150 died by flying into walls.
  • The glide path complied with Civil Aeronautics Board (CAB) regulations for ascent/descent ratios but violated Congress’s minimum altitude rules.

• Flights were within navigable airspace (as defined by federal statute) and thus lawful.
• No physical invasion occurred; any harm was incidental and non-compensable.
• The claim sounded in tort (nuisance), not eminent domain, and the Court of Claims lacked jurisdiction under the Tucker Act.
• Congress, not the courts, should address aviation-related property conflicts.

• Flights constituted a direct physical invasion of property, appropriating an easement for public use (military operations).
• The invasion destroyed the property’s utility (poultry farming), amounting to a taking under the Fifth Amendment.
• Federal aviation regulations did not authorize flights at altitudes causing such direct harm.

• Procedural Issues:
  • Whether the Court of Claims had jurisdiction under the Tucker Act.
  • Whether the claim was properly framed as a taking (not a tort).
• Substantive Issues:
  • Whether low-altitude flights over private land constitute a "taking" of property under the Fifth Amendment.
  • Whether landowners retain compensable rights in airspace below federally designated "navigable airspace."

• Procedural:
  • The Court of Claims had jurisdiction. The suit alleged a taking (contractual claim under the Fifth Amendment), not a tort.
• Substantive:
• Yes. The flights were a taking. The SC held:
  • Land ownership includes airspace necessary for use and enjoyment ("usable airspace").
  • Flights below the minimum altitudes set by Congress (500/1,000 feet) that directly interfere with land use are invasions of this airspace.
  • Such invasions, if sufficiently direct, frequent, and low, appropriate an easement and constitute a taking requiring just compensation.
  • The Causbys were entitled to damages for the easement taken.

• Aerial Easement Doctrine — The SC created a new property interest: an "easement" in airspace appropriated by the government through low-altitude flights. This easement is compensable under the Fifth Amendment.
• "Taking" under the Fifth Amendment — A taking occurs when government action deprives property of all economically beneficial use or, as here, directly appropriates a property interest (here, an easement).
• Usable Airspace Doctrine — Landowners control only the airspace necessary for the ordinary use and enjoyment of their land. Above that, airspace is "navigable commons" subject to public right of transit.

• "The landowner owns at least as much of the space above the ground as he can occupy or use in connection with the land."
• "Flights over private land are not a taking unless they are so low and so frequent as to be a direct and immediate interference with the enjoyment and use of the land."
• "The United States has not condemned the easement; but it has taken it. The owner is entitled to compensation."

• Portsmouth Harbor Land Co. v. United States (1919) — Established that repeated government invasions of airspace could constitute a taking.
• Hinman v. Pacific Air Transport (1937) — Rejected the absolute ad coelum rule; recognized public right to navigate airspace.
• Pennsylvania Coal v. Mahon (1922) — Found that regulation reducing property value could be a taking ("diminution in value" test).

• Fifth Amendment, U.S. Constitution — "Nor shall private property be taken for public use, without just compensation."
• Air Commerce Act of 1926 (49 U.S.C. § 180) — Defined "navigable airspace" and set minimum flight altitudes.
• Tucker Act (28 U.S.C. § 1491) — Granted jurisdiction to the Court of Claims for claims against the U.S.

• Justice Frankfurter (Concurring) — Agreed with the result but emphasized Congress’s role in balancing aviation needs and property rights.

• Justice Black (Dissenting, joined by Burton) — Argued:
  • The claim sounded in tort (nuisance), not takings.
  • Flights were within CAB-authorized glide paths and thus lawful.
  • Compensation should not be required for incidental damages from lawful government operations.
  • The decision encroached on Congress’s authority to regulate aviation.