SUMMARY
Mechanisms to Address Off-Airport Obstructions

Demand for air travel has increased in recent years, and by 2024 in the United States, the total number of passengers flown surpassed the pre-pandemic 2019 record of 1.052 trillion, reaching 1.107 trillion. Operations have grown as well, with over 9.73 million commercial operations in the U.S., and general aviation is growing from 21.8 million flight hours in 2019 to nearly 25 million in 2023. With this record number of flights, increased flight hours in general aviation, and the potential exponential growth of advanced air mobility, ensuring a safe operating environment free from obstructions is more important than ever. Protecting airport approaches, departures, and flight routes from intrusion by tall objects ensures the safety of people on the ground and in the aircraft. In the absence of zoning standards intended to restrict obstructions, communities may inadvertently permit development that results in such impediments. Aviation obstructions are objects that pose a potential hazard to aircraft navigation, such as tall buildings, towers, natural features like mountains and trees, and even temporary structures like construction cranes. These obstructions that impact airport operations can negatively affect the capacity and safety of the airspace.

The Federal Aviation Administration (FAA) encourages and assists airports, states, communities, and residents near airports with efforts to secure the environment around airports to be safe and free from obstructions and hazards. There are various federal resources on obstructions and land use compatibility, as detailed in this synthesis. Obstructions and hazards to airport navigation can be significant, impacting the safety of airport users and the capacity and usability of the airport facilities. The FAA has published resources regarding airport obstructions, including Parts 77 and 150 of Title 14 of the Code of Federal Regulations (14 CFR) and Advisory Circular (AC) 150/5300-13, “Airport Design.” Because land use planning and regulation are powers reserved to the states and localities, it is important that airport sponsors be cognizant of the distribution of regulatory and enforcement authority among federal, state, and local governments. States possess the authority to implement and enforce legislative mandates intended to manage aspects of the state airport systems and related public investments.

The objective of this synthesis was to collect information on the mechanisms that airports use to address obstructions outside the airport boundary. This synthesis summarizes the activities airports of all sizes are taking to address off-airport obstructions, interactions with landowners, and the time and cost they are dedicating to efforts related to obstructions outside the airport property. The study was conducted through a survey sampling of the primary airports in the United States, ranging from Large Hub primary airports to Non-Hub primary airports. The survey examined key aspects of how airports are addressing

off-airport obstructions, from the preliminary planning stages through construction, and maintenance/growth over time. The survey included:

• Support that the airport receives from local, state, and federal authorities
• Outreach and communication that airports use to be proactive in addressing obstructions from local government departments and local landowners
• The frequency with which airport staff encounter obstructions, the time allocated, the time taken to resolve obstruction issues, and the costs associated with those efforts

The online survey was sent to airport managers at airports classified as primary airports, those with scheduled air carrier service and 10,000 or more enplaned passengers per year. A total of 305 surveys were sent to Large Hub, Medium Hub, Small Hub, and Non-Hub Primary airports, representing activity at 320 airports in the United States. Sixty-eight airports completed surveys. Follow-up interviews with a select number of airports were then used to provide case examples of various programs, projects, and airport approaches to obstructions. The survey results and interviews collected from this study provide a snapshot of the current mechanisms airports are using to keep obstructions off the airport property, with the following key conclusions:

• There is no one-size-fits-all approach to airport obstructions. Some obstructions are temporary and can be addressed immediately, such as a crane installing heating, ventilation, and air conditioning (HVAC) equipment on a nearby buildingʼs roof. Some airports have much longer processes, such as legal intervention when deeds/easements are not in place and property owners are not compliant. Local and state regulations, as well as political considerations, also influence obstruction mitigation.
• Outreach to local landowners is underway, and airports are building relationships with neighbors, so when obstructions do become an issue, they can work together. Airports use websites and emails as regular forms of communication, and they also use door-to-door communication to connect with surrounding property owners.
• Airport staff are being proactive in addressing obstructions and are not relying on a single mechanism to avoid or mitigate them. Airports meet, train, and are in constant communication with city planning departments about the requirements of aviation surfaces. The airports are also involved in developing compatible land use plans that account for obstructions, obtaining aviation easements when possible, enforcing deed requirements, leveraging state department of transportation (DOT) expertise, and obtaining funding from various sources to support a safe airport and airspace.
• Airports of all sizes use FAA staff, web resources, and documents to assist in the obstruction mitigation process. Airports and their surrounding areas promote the Obstruction Evaluation/Airport Airspace Analysis process to owners, developers, and contractors.