ACRP OVERSIGHT COMMITTEE^*

CHAIR

Cathryn Stephens

Eugene Airport

VICE CHAIR

Chad Makovsky

Phoenix Sky Harbor International Airport

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

Greater Orlando Aviation Authority

Ramon Ricondo

Ricondo and Associates, Inc.

Atif Saeed

San Diego County Regional Airport Authority

Jesus H. Saenz, Jr.

San Antonio Airport System

Jessica Sypniewski

Federal Aviation Administration

EX OFFICIO MEMBERS

Justin Barkowski

American Association of Airport Executives

Ann M. Brach

Transportation Research Board

John Heimlich

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

[Vacant]

U.S. Environmental Protection Agency

SECRETARY

Monique R. Evans

Transportation Research Board

_______________________

^* Membership as of May 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: Ann M. Brach, 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

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, Distinguished Senior Research Scientist, Rensselaer Polytechnic Institute, Troy, 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

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

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

Jamie Pfister, Administrator, Federal Transit Administration, Washington, DC

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 May 2026.

AIRPORT COOPERATIVE RESEARCH PROGRAM

ACRP RESEARCH REPORT 284

Transitioning to Unleaded Aviation Gasoline

A GUIDE AND TOOLS

Jim Lyons

Trinity Consultants

Phoenix, AZ

Shaun Germolus

AirportAdmin, LLC

Kissimmee, FL

Bernard Robertson

BIR1

Bloomfield Hills, MI

Jay Turner

Washington University in St. Louis

Saint Louis, MO

Jeremy Heiken

Oak Leaf Environmental

Dexter, MI

Subscriber Categories

Aviation • Environment • Vehicle and Equipment

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 RESEARCH REPORT 284

Project 03-73
ISSN 2572-3731 (Print)
ISSN 2572-374X (Online)
ISBN 978-0-309-60513-7
Library of Congress Control Number 2026940024

© 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 research 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.

Published research reports of the

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.

The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president.

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 RESEARCH REPORT 284

Monique R. Evans, Director, Cooperative Research Programs

Waseem Dekelbab, Deputy Director, Cooperative Research Programs

Marci A. Greenberger, Manager, Airport Cooperative Research Program

Joseph D. Navarrete, Senior Program Officer (retired)

Matthew J. Griffin, Senior Program Officer

Brittany Summerlin-Azeez, Program Coordinator

Natalie Barnes, Director of Publications

Brian Haefs, Associate Director of Publications

Alison Shapiro, Editor

ACRP PROJECT 03-73 PANEL
Field of Policy and Planning

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

David Decoteau, King County, WA, Seattle, WA

Kyle OʼLeary, Independent Consultant, Haltom City, TX

Mary Ashburn Pearson, Delta Airport Consultants, Inc., Richmond, VA

Jorge Rubio, City of San Diego, San Diego, CA

Ralph J. Iovinelli, FAA Liaison

William Reinhardt, FAA Liaison

Bryan Manning, U.S. EPA Liaison

Joshua Ainley, Airports Council International–North America Liaison

FOREWORD

By Matthew J. Griffin
Staff Officer
Transportation Research Board

ACRP Research Report 284: Transitioning to Unleaded Aviation Gasoline: A Guide and Tools provides airports with an overview and actionable guidance for transitioning to unleaded aviation gasoline (avgas). A coordination plan was developed to understand ongoing efforts at the Federal Aviation Administration (FAA), the Environmental Protection Agency (EPA), and within the general aviation industry, and a case study plan was developed to identify pertinent airports and stakeholders. This guide and the additional resources will be useful to the United States aviation industry, with an emphasis towards airports that are transitioning to unleaded avgas.

The EPA has announced a proposed determination that emissions of lead from aircraft that operate on leaded fuel cause or contribute to air pollution that may reasonably be anticipated to endanger public health and welfare. The FAA and the aviation industry have set a goal and made a commitment to eliminate the use of leaded avgas by the end of 2030 without adversely affecting the safe and efficient operation of the existing piston-engine fleet. Achieving this goal will require airports to play a significant role, namely, taking steps to accommodate and offer unleaded avgas while maintaining 100-octane low-lead availability.

In early 2022, a government-industry partnership named Eliminate Aviation Gasoline Lead Emissions (EAGLE) was formed with a broad range of activities, including developing fuel infrastructure and access viability; supporting research, development, and innovation; evaluating and authorizing safe fuels; and establishing necessary policies. To complement the broad scope of the EAGLE initiative, a more focused research effort was also needed to help individual airports transition to unleaded avgas in a manner that was safe, efficient, and cost-effective and that did not disrupt piston-engine activity.

Under ACRP Project 03-73, “Airport Guide for Transitioning to Unleaded Aviation Gasoline,” Trinity Consultants was asked to produce a primer, guide, tools, and resources to help airports conduct a safe and efficient transition to unleaded avgas while maintaining continuity of service. An assessment of the future leaded avgas needs of the United States piston-engine aircraft fleet was performed, as well as a review of any available incentives, grants, and other funding mechanisms that could be leveraged for the development, distribution, and use of unleaded gasoline. A critical assessment of these findings, along with the findings of the case study plan, was performed, and the results were summarized in ACRP Research Report 284 and used to develop the additional tools.

In addition to ACRP Research Report 284, the following materials are available at nationalacademies.org/publications by searching for ACRP Research Report 284: Transitioning to Unleaded Aviation Gasoline: A Guide and Tools:

• Tool 1. Transition Process Checklist Tool.
• Tool 2. Individual Aircraft Unleaded Fuel Survey Tool.
• Tool 3. Multiple Aircraft Unleaded Fuel Survey Tool.
• Tool 4. Airport Unleaded Fuel Aircraft Inventory Tool.
• Tool 5. Unleaded Fuel Cost Evaluation Tool.

A Primer intended to provide airports with concise information about the transition to unleaded avgas accompanies this publication and can be found at nationalacademies.org/publications by searching for Understanding the Transition to Unleaded Aviation Gasoline: A Primer.

CONTENTS

Chapter 1 Introduction

Overview

Available Unleaded Aviation Gasolines and Determining Aircraft Compatible with Their Use

Chapter 2 Ten Steps for Transitioning to Supplying Unleaded Aviation Gasoline Alongside 100LL Through 2030

Step 1. Communicate with Fuel Suppliers and FBOs

Step 2. Characterize the Airport Fleet for Unleaded Fuel Compatibility

Step 3. Estimate Unleaded Fuel Demand and Evaluate Refueling Infrastructure

Step 4. Identify Potential Transition Funding Sources

Step 5. Perform Financial Analysis of Transition Options

Step 6. Decide on the Transition to Unleaded Fuel and Select the Fuel Type

Step 7. Implement Transition Plans to Unleaded Fuel

Step 8. Develop Safety Procedures

Step 9. Conduct Training, Outreach, and Education

Step 10. Monitor the Transition, Identify Issues, and Make Adjustments

Chapter 3 Tools to Assist with Transition Activities

References

Appendix A Airport Summaries

Appendix B Naples Airport UL94 Unleaded Fuel SOP