ACRP OVERSIGHT COMMITTEE^*

CHAIR

Cathryn Stephens
Eugene Airport

VICE CHAIR

Chad Makovsky
City of Phoenix (Arizona)

MEMBERS

Clara Bennett
Boca Raton Airport Authority

Lee Brown
JetBlue

Melissa Cooper
Kansas City Aviation Department

Marianne Csaky
LanzaJet

Darryl Daniels
Jacobsen Daniels Associates

Kimberly A. Kenville
University of North Dakota

Lance Lyttle
Seattle-Tacoma International Airport

Ramon Ricondo
Ricondo and Associates, Inc.

Atif Saeed
Philadelphia International Airport

Jesus H. Saenz, Jr.
San Antonio Airport System

Jessica Sypniewski
Federal Aviation Administration

EX OFFICIO MEMBERS

Justin Barkowski
American Association of Airport Executives

[Vacant]
U.S. Environmental Protection Agency

Laura Rinaldi McKee
Airlines for America

Christopher J. Oswald
Airports Council International–North America

Gregory Pecoraro
National Association of State Aviation Officials

T.J. Schulz
Airport Consultants Council

Victoria Sheehan
Transportation Research Board

SECRETARY

Monique R. Evans
Transportation Research Board

__________________________

^*Membership as of February 2026.

TRANSPORTATION RESEARCH BOARD 2026 EXECUTIVE COMMITTEE*

OFFICERS

Chair: Joel M. Jundt, Secretary of Transportation, South Dakota Department of Transportation, Pierre

Vice Chair: Randell Iwasaki, President and CEO, Iwasaki Consulting Services, Walnut Creek, CA

Executive Director: Victoria Sheehan, Transportation Research Board, Washington, DC

MEMBERS

James F. Albaugh,President and CEO, The Boeing Company (retired), Scottsdale, AZ

Marsha Anderson Bomar,Strategic Transportation Advisor, GHD, Duluth, GA

Douglas C. Ceva,Vice President, Customer Lead Solutions, Prologis, Inc., Jupiter, FL

Nancy Daubenberger,Commissioner of Transportation, Minnesota Department of Transportation, St. Paul

Garrett Eucalitto,Commissioner, Connecticut Department of Transportation, Newington

Andrew Fremier,Executive Director, Metropolitan Transportation Commission, San Francisco, CA

Martha Grabowski,Professor Emerita, Information Systems, Le Moyne College, Madden College of Business and Economics, Cazenovia, NY

Edward Hassinger,Director, Missouri Department of Transportation, Jefferson City

Shante Hastings,Cabinet Secretary, Delaware Department of Transportation, Dover

Carol A. Lewis,Professor, Transportation Studies, Texas Southern University, Houston

Ricardo Martinez,Adjunct Professor of Emergency Medicine, Emory University School of Medicine, Decatur, GA

Russell McMurry,Commissioner, Georgia Department of Transportation, Atlanta

Craig E. Philip,Research Professor and Director, VECTOR, Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN

Steward T.A. Pickett,Distinguished Senior Scientist, Cary Institute of Ecosystem Studies, Millbrook, NY

Leslie S. Richards,Professor of Practice, University of Pennsylvania, Philadelphia

Tracy Larkin Thomason,Director, Nevada Department of Transportation, Carson City

Marc Williams,Executive Director, Texas Department of Transportation, Austin

EX OFFICIO MEMBERS

Derek Barrs,Administrator, Federal Motor Carrier Safety Administration, Washington, DC

Steven G. Bradbury,Deputy Secretary, U.S. Department of Transportation, Washington, DC

Stephen Carmel,Administrator, U.S. Maritime Administration, Washington, DC

Tara Cavalline,Professor, University of North Carolina, Charlotte, and Chair, TRB Technical Activities Council

David Fink,Administrator, Federal Railroad Administration, Washington, DC

Firas Ibrahim,Director, Office of Research, Development, and Technology, Office of the Assistant Secretary for Research and Technology, Washington, DC

Jason Kelly,Deputy Commanding General for Civil Works and Emergency Operations, U.S. Army Corps of Engineers, Washington, DC

Sandra Knight,President, WaterWonks, LLC, Washington, DC, and Chair, TRB Marine Board

Sean McMaster,Administrator, Federal Highway Administration, Washington, DC

Marcus J. Molinaro,Administrator, Federal Transit Administration, Washington, DC

Jonathan Morrison,Administrator, National Highway Traffic Safety Administration, Washington, DC

Seval Oz,Senior Advisor, Office of the Assistant Secretary for Research and Technology, Washington, DC

Niloo Parvinashtiani,Engineer, Mobility Consultant Solutions, Iteris Inc., Fairfax, VA, and Chair, TRB Young Participants Council

Paul Roberti,Administrator, Pipeline and Hazardous Materials Safety Administration, Washington, DC

Paul P. Skoutelas,President and CEO, American Public Transportation Association, Washington, DC

Jim Tymon,Executive Director, American Association of State Highway and Transportation Officials, Washington, DC

__________________________

^* Membership as of February 2026.

AIRPORT COOPERATIVE RESEARCH PROGRAM

ACRP SYNTHESIS 142

Mechanisms to Address Off-Airport Obstructions

A Synthesis of Airport Practice

Christopher D. Grant

Timothy Rudolph

Nolan Metz

Embry-Riddle Aeronautical University

Daytona Beach, FL

Subscriber Categories

Aviation • Planning and Forecasting • Terminals and Facilities

Research sponsored by the Federal Aviation Administration

2026

AIRPORT COOPERATIVE RESEARCH PROGRAM

Airports are vital national resources. They serve a key role in transportation of people and goods and in regional, national, and international commerce. They are where the nationʼs aviation system connects with other modes of transportation and where federal responsibility for managing and regulating air traffic operations intersects with the role of state and local governments that own and operate most airports. Research is necessary to solve common operating problems, to adapt appropriate new technologies from other industries, and to introduce innovations into the airport industry. The Airport Cooperative Research Program (ACRP) serves as one of the principal means by which the airport industry can develop innovative near-term solutions to meet demands placed on it.

The need for ACRP was identified in TRB Special Report 272: Airport Research Needs: Cooperative Solutions in 2003, based on a study sponsored by the Federal Aviation Administration (FAA). ACRP carries out applied research on problems that are shared by airport operating agencies and not being adequately addressed by existing federal research programs. ACRP is modeled after the successful National Cooperative Highway Research Program (NCHRP) and Transit Cooperative Research Program (TCRP). ACRP undertakes research and other technical activities in various airport subject areas, including design, construction, legal, maintenance, operations, safety, policy, planning, human resources, and administration. ACRP provides a forum where airport operators can cooperatively address common operational problems.

ACRP was authorized in December 2003 as part of the Vision 100—Century of Aviation Reauthorization Act. The primary participants in the ACRP are (1) an independent governing board, the ACRP Oversight Committee (AOC), appointed by the Secretary of the U.S. Department of Transportation with representation from airport operating agencies, other stakeholders, and relevant industry organizations such as the Airports Council International-North America (ACI-NA), the American Association of Airport Executives (AAAE), the National Association of State Aviation Officials (NASAO), Airlines for America (A4A), and the Airport Consultants Council (ACC) as vital links to the airport community; (2) TRB as program manager and secretariat for the governing board; and (3) the FAA as program sponsor. In October 2005, the FAA executed a contract with the National Academy of Sciences formally initiating the program.

ACRP benefits from the cooperation and participation of airport professionals, air carriers, shippers, state and local government officials, equipment and service suppliers, other airport users, and research organizations. Each of these participants has different interests and responsibilities, and each is an integral part of this cooperative research effort.

Research problem statements for ACRP are solicited periodically but may be submitted to TRB by anyone at any time. It is the responsibility of the AOC to formulate the research program by identifying the highest priority projects and defining funding levels and expected products.

Once selected, each ACRP project is assigned to an expert panel appointed by TRB. Panels include experienced practitioners and research specialists; heavy emphasis is placed on including airport professionals, the intended users of the research products. The panels prepare project statements (requests for proposals), select contractors, and provide technical guidance and counsel throughout the life of the project. The process for developing research problem statements and selecting research agencies has been used by TRB in managing cooperative research programs since 1962. As in other TRB activities, ACRP project panels serve voluntarily without compensation.

Primary emphasis is placed on disseminating ACRP results to the intended users of the research: airport operating agencies, service providers, and academic institutions. ACRP produces a series of research reports for use by airport operators, local agencies, the FAA, and other interested parties; industry associations may arrange for workshops, training aids, field visits, webinars, and other activities to ensure that results are implemented by airport industry practitioners.

ACRP SYNTHESIS 142

Project 11-03, Topic S09-11
ISSN 1935-9187
ISBN 978-0-309-60521-2
Library of Congress Control Number 2026939148

© 2026 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trademarks of the National Academy of Sciences. All rights reserved.

COPYRIGHT INFORMATION

Authors herein are responsible for the originality and accuracy of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein.

The National Academy of Sciences (NAS) grants permission to reproduce written material in this publication for classroom and non-commercial purposes subject to the rights of any third parties and appropriate attribution. Permission is given with the understanding that none of the material will be used to imply NAS, TRB, AASHTO, APTA, FAA, FHWA, FTA, GHSA, or NHTSA endorsement of a particular product, method, or practice. For other uses of the written material, users must request permission from the National Academies Press.

NOTICE

The report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine.

Any opinions, findings, and conclusions or recommendations expressed or implied in this document are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; or the program sponsors.

The Transportation Research Board does not develop, issue, or publish standards or specifications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications.

The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of the Airport Cooperative Research Program do not endorse products or manufacturers. Trade or manufacturersʼ names or logos appear herein solely because they are considered essential to the object of the report.

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AIRPORT COOPERATIVE RESEARCH PROGRAM

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The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president.

The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. Tsu-Jae Liu is president.

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The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine.

Learn more about the National Academies of Sciences, Engineering, and Medicine at www.nationalacademies.org.

The Transportation Research Board is one of four centers of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to mobilize expertise, experience, and knowledge to anticipate and solve complex transportation-related challenges. The Boardʼs varied activities annually engage more than 5,500 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state departments of transportation, federal agencies including component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation.

Learn more about the Transportation Research Board at www.TRB.org.

COOPERATIVE RESEARCH PROGRAMS

CRP STAFF FOR ACRP SYNTHESIS 142

Monique R. Evans,Director, Cooperative Research Programs

Waseem Dekelbab,Deputy Director, Cooperative Research Programs

Marci A. Greenberger,Manager, Airport Cooperative Research Program

Jordan Christensen,Senior Program Officer

Demisha Williams,Senior Program Assistant

Natalie Barnes,Director of Publications

Brian Haefs,Associate Director of Publications

ACRP PROJECT 11-03 PANEL

Scott Wintner,San Jose Norman Y. Mineta International Airport, San Jose, CA (Chair)

Rhona DiCamillo,DKMG Consulting, LLC, Ponte Vedra Beach, FL

Bryant Francis,Cleveland Airport System, Cleveland, OH

Kimberly A. Kenville,University of North Dakota, Grand Forks, ND

Mark R. Richter,Ricondo & Associates, Inc, Denver, CO

Cameron Thompson,Birmingham Airport Authority, Birmingham, AL

Keila Walker-Denis,Orlando International Airport, Orlando, FL

Patrick W. Magnotta,FAA Liaison

Liying Gu,Airports Council International–North America Liaison

Christine L. Gerencher,TRB Liaison

Topic S09-11 PANEL

Mujeeb A. Basha,American Veteran Engineering, PLLC, Lombard, IL

Rylan Juran,Minnesota Department of Transportation, St. Paul, MN

Enrique Sanabria,Port Authority of New York and New Jersey, New York, NY

Nino Sapone,Bishop International Airport Authority, Flint, MI

Eric T. Smith,Kaplan Kirsch LLP, Washington, DC

Stephanie Ward,Mead & Hunt, Inc., Lansing, MI

Anthony Cochran,FAA Liaison

ABOUT THE ACRP SYNTHESIS PROGRAM

Airport administrators, engineers, and researchers often face problems for which information already exists, either in documented form or as undocumented experience and practice. This information may be fragmented, scattered, and unevaluated. As a consequence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem.

There is information on nearly every subject of concern to the airport industry. Much of it derives from research or from the work of practitioners faced with problems in their day-to-day work. To provide a systematic means for assembling and evaluating such useful information and to make it available to the entire airport community, the Airport Cooperative Research Program authorized the Transportation Research Board to undertake a continuing project. This project, ACRP Project 11-03, “Synthesis of Information Related to Airport Practices,” searches out and synthesizes useful knowledge from all available sources and prepares concise, documented reports on specific topics. Reports from this endeavor constitute an ACRP report series, Synthesis of Airport Practice.

This synthesis series reports on current knowledge and practice, in a compact format, without the detailed directions usually found in handbooks or design manuals. Each report in the series provides a compendium of the best knowledge available on those measures found to be the most successful in resolving specific problems.

FOREWORD

By Jordan Christensen
Staff Officer
Transportation Research Board

ACRP Synthesis 142: Mechanisms to Address Off-Airport Obstructions presents the state of practice of airport methods to address obstructions located off airport property. The synthesis includes information on activities airports take to address obstructions, including outreach with landowners and other stakeholders, time and costs to resolve issues, and support and coordination from local, state, and federal authorities.

Under ACRP Project 11-03/Topic S09-11, “Survey of Mechanisms to Address Off Airport Obstructions,” Embry-Riddle Aeronautical University was asked to synthesize and document the various mechanisms airports use to address obstructions, with a focus on obstructions that are outside of the airport boundary. Information used in this study was obtained through a literature review, a survey of airports, and interviews to develop in-depth case examples.

This synthesis is an immediately useful document that records the practices that were acceptable within the limitations of the knowledge available at the time of its preparation. As progress in research and practices continues, new knowledge will be added to that now at hand. The audience for this synthesis is airport sponsors, local permitting authorities, state aviation officials, and non-airport stakeholders that are involved in addressing off-airport obstructions.

Appendix C: Case Example Interview Script, Appendix D: LAS Directorʼs Permit Application and Property Ownerʼs Shielding Determination Statement, and Appendix E: LEB Construction and Alterations Questions are not printed here but are available at nationalacademies.org/publications by searching for ACRP Synthesis 142: Mechanisms to Address Off-Airport Obstructions.

CONTENTS

Summary

Chapter 1 Introduction

Synthesis Objectives

Synthesis Scope and Approach

Synthesis Organization

Chapter 2 Literature Review: Airport Obstructions and Navigable Airspace

Introduction to Off-Airport Obstructions

Resources for Airports to Address Obstructions

Chapter 3 Survey Results 

Survey Overview

Local, State, and Federal Support

Notification of Construction Activity

Outreach and Communication

Cost of Addressing Obstructions

Amount/Number of Obstructions

Funding

Impacts

Challenges to Implementation

Chapter 4 Case Examples

Harry Reid International Airport (LAS), Las Vegas, Nevada

Phoenix Sky Harbor International Airport (PHX), Phoenix, Arizona

Central Pennsylvania Airports (MDT, CXY, N68, W05)

Piedmont Triad International Airport (GSO), Greensboro, North Carolina

Sioux Falls Regional Airport (FSD), Sioux Falls, South Dakota

Lebanon Municipal Airport (LEB), West Lebanon, New Hampshire

Orlando Executive Airport (ORL), Orlando, Florida

Owosso Community Airport (RNP), Owosso, Michigan

Chapter 5 Summary of Findings and Suggestions for Future Research

Summary

Suggestions for Future Research

References and Bibliography 

Appendix A Survey

Appendix B  Survey Responses

Appendices C, D, and E