Airspace and the takings clause.

• Author: Rule, Troy A.
• Position: I. Airspace Rights and the Power of Eminent Domain through III. Filling the gap: A Takings rule for Veiled Airspace Easement Regulations, p. 421-455

1. AIRSPACE RIGHTS AND THE POWER OF EMINENT DOMAIN A. Airspace Rights under Common Law B. Airspace Rights in Eminent Domain Proceedings II. VEILED AIRSPACE EASEMENTS AND REGULATORY TAKINGS LAW A. Examples of Veiled Airspace Easement Regulations 1. Restricting Wind Farms to Protect Military Radar 2. Imposing Height Restrictions to Create Buffers near Airports 3. Imposing Height Restrictions to Prevent the Shading of Municipal Solar Energy Installations 4. Using Height Restrictions to Preserve Scenic Views for Government Buildings B. Analysis of Veiled Airspace Easement Regulations under Existing Takings Law 1. Per Se Physical Takings under Loretto? 2. Total Regulatory Takings under Lucas? 3. Partial Takings under Penn Central? III. Filling the gap: a takings rule for veiled airspace Easement Regulations A. Element #1: Deprivation of a Possessory Interest in Airspace B. Element #2: Government Use of the Regulated Space 1. Previous Calls for a Government Use Test: Enterpriser vs. Arbiter 2. The Distinguishing Power of a Government Use Requirement C. Measuring Just Compensation IV. Benefits and Challenges of the Additional Takings Rule A. More Efficient Use of Airspace B. Greater Clarity in Takings Law C. Clearer Laws Regarding Airport Height Restrictions D. Clearer Takings Rules for Wind Energy Development E. Potential Criticisms of the Proposed Takings Rule 1. A New Avenue for Frivolous Takings Claims? 2. An Incentive to Excessively Restrict Airspace? 3. An Invitation for New Takings Claims Against Airports? Conclusion INTRODUCTION

   Without ever venturing into the open airspace above private land, public entities can use that space to preserve scenic views for government buildings, to deliver sunlight to publicly-owned solar panels, to transmit military radar signals, or to serve other valuable functions. (1) This ability for governments to use private airspace without physically invading it has important implications in the context of takings law. Public entities typically acquire private property through voluntary sales or eminent domain, compensating citizens for the acquired property. However, governments can sometimes secure their nonphysical uses of private airspace at far less expense by simply restricting the space rather than formally taking it. Through height restrictions or other land-use controls, public entities can take the equivalent of negative airspace easements tailored to serve their own interests. Such restrictions seek not to govern land use conflicts among private landowners but to conscript specific airspace into government service.

   Regulations designed to keep airspace open so it can serve a non-trespassory government use typically are not compensable under existing regulatory takings law. Governments can often impose such restrictions without risking takings liability, even though the effective transfer of property rights resulting from such restrictions often mirrors that of an overt taking through eminent domain. Modern regulatory takings jurisprudence focuses heavily on whether the challenged government action involves a physical invasion of the claimant's property or whether it denies the claimant of all economically viable use of the parcel at issue. These shorthand tests, commonly known as the Loretto and Lucas rules, (2) succeed in detecting many types of government actions that warrant the payment of just compensation under the Takings Clause. However, neither of these rules accounts for instances when public entities restrict private airspace solely so that they can exploit it in ways that require no physical invasion. Landowners whose properties are subjected to such restrictions are thus left to argue their claims under the nebulous test set forth in Penn Central, (3) with slim chances of success. The legitimate police power restrictions of airspace upheld in Penn Central are materially different from the abuses of regulatory authority aimed at enhancing a public entity's own resource position that are described in this Article. (4) Unfortunately, most courts have heretofore been unable or unwilling to recognize this distinction when adjudicating takings claims over airspace. (5)

   The imprecision of the Supreme Court's takings jurisprudence relating to airspace rights is increasingly problematic in this era of unprecedented competition for airspace. Airspace is a critical resource for renewable energy and sustainable development. Commercial wind turbines must extend hundreds of feet into rural skies to be fully productive. (6) Solar panels require vast amounts of open airspace to access direct sunlight. (7) And vertical development that extends high into urban airspace is a significant strategy for combating suburban sprawl. (8) As airspace grows ever more important in the coming years, conflicts between private citizens and governments over it will likely grow as well. Regulatory takings law in its present form is ill-equipped to fairly and efficiently govern these conflicts.

   This Article draws attention to "veiled airspace easement regulations"--government-imposed restrictions that transfer the practical equivalent of negative airspace easements to public entities. Arguing that such regulations are exactly the sorts of government actions that the Takings Clause was intended to protect against, this Article advocates treating these regulations as compensable takings. Part I of this Article highlights courts' longtime recognition of airspace rights as constitutionally protected property, including such recognition within the parallel context of eminent domain proceedings. Part II describes four specific examples of situations in which governments can abuse their regulatory power to effectively acquire valuable interests in private airspace and explains how the unique attributes of airspace have led courts to overlook these scenarios in their takings jurisprudence. Part III suggests that the supreme Court should consider adopting an additional, supplemental takings rule that requires just compensation to landowners when regulations (i) deprive them of possessory interests in airspace (ii) for the primary purpose of securing the government's own exploitation of that space. Part III also discusses principles set forth in previous writings by Professors Joseph Sax and Jed Rubenfeld that could assist courts in distinguishing ordinary police power regulations of airspace from regulations involving such direct government exploitation of the restricted space that just compensation would be warranted under the proposed rule. Part IV argues that this new takings rule would add sorely-needed clarity to an ambiguous area of regulatory takings law and would promote more just and efficient allocations of airspace rights between public entities and private landowners.

1. Airspace Rights and the Power of Eminent Domain

   Airspace, the layer of open space that blankets the earth's surface, is a complex and oft-forgotten natural resource. Airspace is as immovable and unique as land but differs in that it is also totally invisible and intangible. (9) Given airspace's peculiar attributes, it is unsurprising that courts and legal scholars have long struggled to formulate rules to govern its use. (10)

   For centuries, neighbors have quarreled over conflicting uses of the airspace above their land. (11) Common law doctrines and statutory rules have gradually evolved to address many of these conflicts among private landowners. (12) However, as the function of government has expanded over time, (13) public entities have increasingly made uses of airspace as well. When a government's use of private airspace clashes with a landowner's use of the space, perplexing legal questions can arise. Should the airspace rights in dispute receive the same property protections commonly afforded to surface land? And under what conditions should the law permit public entities to confiscate or interfere with those rights?

   The Takings Clause of the Fifth Amendment is the obvious launching point for analyzing conflicts between governments and citizens over private airspace. Its brief language prohibits governments from taking "private property ... for public use, without just compensation." (14) A threshold question that arises out of this language is whether the assets at issue in any regulatory taking case are legally cognizable "property" at all. (15) As the following parts show, longstanding case law and more than 70 years of compensated takings of airspace easements through eminent domain are evidence that airspace rights are indeed "property" under the Takings Clause. (16)

   1. Airspace Rights under Common Law

      Landowners have long held common law property rights in the low-altitude airspace above their parcels. (17) The origins of modern airspace law date as far back as the 1300s, when the Italian jurist Cino da Pistoia wrote, "Cuius est solum, eius est usque ad coelum," (18) or "[to] whomsoever the soil belongs, he owns also to the sky." (19) This simple "ad coelum doctrine" distributes airspace rights based on ownership of the surface land situated immediately below the space. The doctrine appeared in Coke's commentaries (20) and in Blackstone's commentaries, (21) securing its place within English and American common law. (22) By the early 1900s, courts in the United States were applying it to find trespass for even minor intrusions into neighboring airspace. (23)

      The United states Congress and the courts clarified the scope of landowners' airspace rights in the early twentieth century when airplanes began taking to the skies. (24) Federal legislation enacted during that period carefully defined "navigable airspace," which generally encompasses all space situated more than 500 feet above the ground, (25) and designated that space as a nationally-shared common area for modern flight. (26) Although the Supreme Court acknowledged navigable airspace legislation in United States v. Causby in 1946, characterizing...