Nonroad Engines, Equipment, and Vehicles

Aircraft

Contrails

Contrails are line-shaped clouds or “Condensation trails” composed of ice particles that are visible behind jet aircraft engines under certain atmospheric conditions and at times can persist. EPA is not aware of any deliberate actions to release chemical or biological agents into the atmosphere. If you have a question, please email us at otaq@epa.gov (or call the contrail information line at 734-214-4432 to hear this message).

Aircraft Contrails Fact Sheet (PDF) (6 pp, 1.6MB, EPA-430-F-00-005, September 2000, reviewed September 2012)
Air Force -- Contrails Facts (PDF) (14 pp, 551K)

Notice of Updates regarding the Public Hearing on the Proposed GHG Endangerment and Contributions Findings for Aircraft under Section 231 of the Clean Air Act

The EPA has issued a Supplemental Notice in the Federal Register which provides three updates regarding the public hearing which is scheduled for August 11, 2015 in Washington DC. First, it corrects a typographical error in the street address for the public hearing and provides notice of availability of a conference call-in number for the public to listen to the hearing. Additionally, this action provides notice that video recording will be allowed in the hearing room provided that it does not interfere with or interrupt the public hearing.

Notice of Updates to Public Hearing (PDF) (2 pp, 200K, published July 29, 2015)

Notice of Public Hearing on the Proposed GHG Endangerment and Contribution Findings for Aircraft under Section 231 of the Clean Air Act

EPA will hold a public hearing on this Proposal on Tuesday, August 11, 2015 in Washington, D.C. The hearing will be held at the U.S. EPA Offices, the William Jefferson Clinton East Building, Room 1153, 1201 Constitution Avenue, NW and will start at 10 am local time.

Speakers should contact Ms. JoNell Iffland to request to speak at the hearing. Speakers are encouraged to pre-register. The last day to preregister in advance to speak at the hearing will be August 6, 2015.

Iffland.jonell@epa.gov

Requests to speak will be taken on the day of the hearing at the hearing registration desk, and accommodated as time permits, although preferences on speaking times may not be able to be fulfilled. Oral testimony will be limited to no more than 10 minutes for each commenter, although we may need to adjust the time for each speaker if there is a large turnout. The EPA requests that commenters provide the EPA with 3 copies of their oral testimony in hard copy form the day of the hearing or an electronic copy in advance of the hearing date. Speakers are encouraged to pre-register.

For further information on the public hearing, including identification requirements for a Federal Building, please see section I.B of the Federal Register notice, 80 FR 37758 (July 1, 2015).

EPA Takes First Steps to Address Greenhouse Gas Emissions from Aircraft

The EPA proposed to find that greenhouse gas (GHG) emissions from certain classes of engines used in aircraft contribute to the air pollution that causes climate change endangering public health and welfare under section 231(a) of the Clean Air Act. At the same time, EPA issued an Advance Notice of Proposed Rulemaking that provides information on the process for setting international CO₂ emissions standards for aircraft at the International Civil Aviation Organization, and describes and seeks input on issues related to setting an international CO₂ standard for aircraft, and the potential use of section 231 of the Clean Air Act to adopt a corresponding aircraft engine standard domestically.

Fact Sheet: EPA Takes First Steps to Address Greenhouse Gases from Aircraft Engines (PDF) (4 pp, 167K, EPA- 420-F-15-023, June 2015)

Proposed Rule and Advanced Notice of Proposed Rulemaking (PDF) (50 pp, 884K, published July 1, 2015)

EPA Notifies ICAO of Timeframe for Initiating U.S. Domestic Process to Address Aircraft GHGs

The United States recently submitted an information paper to the United Nation’s International Civil Aviation Organization (ICAO) that sets out a timeframe for initiating the U.S. domestic regulatory process for addressing greenhouse gas emissions from aircraft under the Clean Air Act.

Information Paper “US Aircraft Greenhouse Gas Rulemaking Process” (PDF) (2 pp, 59K) submitted by the United States to the ICAO/CAEP Steering Group in preparation for the Meeting in Denpasar, Indonesia 15-19 September 2014.
2012 EPA Response to the Petition for Rulemaking Under the Clean Air Act to Reduce the Emission of Air Pollutants from Aircraft that Contribute to Global Climate Change (PDF) (11 pp, 261K).
2011 (PDF) (19 pp, 110k) and 2012 (PDF) (4 pp, 90K) Court Decisions deciding that section 231 (a)(2)(A) requires EPA to make an endangerment finding under the Clean Air Act, and that EPA must respond to the aircraft petition within 90 days of the 2012 court decision.
2007 Petition for Rulemaking Under the Clean Air Act to Reduce the Emission of Air Pollutants from Aircraft that Contribute to Global Climate Change (PDF) (26 pp, 390K) from the Center for Biological Diversity, Center for Food Safety, Friends of the Earth, International Center for Technology Assessment, and Oceana.

NOx Emissions from Commercial Aircraft Engines

EPA Adopts NOx Emission Standards for Aircraft Gas Turbine Engines
EPA adopted emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft. The requirements were previously adopted by the International Civil Aviation Organization (ICAO). Included in the rule are two new tiers of more stringent emission standards for oxides of nitrogen (NOx). These are referred to as Tier 6 standards and Tier 8 standards. The Tier 6 standards become effective for newly-manufactured aircraft engines beginning in 2013.
- Fact Sheet: EPA Adopts NOx Emission Standards for Aircraft Gas Turbine Engines (PDF) (2 pp, 138K, EPA-420-F-12-027, May 2012)
- Control of Air Pollution From Aircraft and Aircraft Engines; Final Emission Standards and Test Procedures (PDF) (46 pp, 732K, published June 18, 2012)
- Control of Air Pollution From Aircraft and Aircraft Engines; Summary and Analysis of Comments
EPA Proposes NOx Emission Standards for Aircraft Gas Turbine Engines
EPA is proposing to adopt emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft. The proposed requirements were either previously adopted by the International Civil Aviation Organization (ICAO), or agreed on at ICAO’s Committee on Aviation Environmental Protection (CAEP) in 2010. Included in the proposal are two new tiers of more stringent emission standards for oxides of nitrogen (NOx). These are referred to as Tier 6 (or CAEP/6) standards and Tier 8 (or CAEP/8) standards. The proposed standards would become effective for newly-manufactured aircraft engines beginning in 2013.
- Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures (PDF) (41 pp, 567K, published July 27, 2011)
Aircraft - Related Organic Gases
The Environmental Protection Agency's (EPA) Office of Transportation Air Quality (OTAQ) and the Federal Aviation Administration's (FAA) Office of Environment and Energy (AEE) are pleased to provide the organic gas speciation profile for use in emission inventories of aircraft equipped with turbofan, turbojet, and turboprop engines fueled with kerosene-based jet-A fuel. The development of this profile is the combined work of both agencies, taking into account the most recent data sets available at this time. EPA and FAA have agreed to continue further development of this speciated organic gas profile as new scientific information becomes available. Because this effort is a "living" methodology, air quality practitioners should verify that they have the most recent version of the documents (by date and version number on the cover) and associated speciated profile before preparing an emissions inventory.
- Recommended Best Practice for Quantifying Speciated Organic Gas Emissions from Aircraft Equipped with Turbofan, Turbojet, and Turboprop Engines (PDF) (26 pp, 626K, EPA-420-R-09-901, May 2009)
  This document will assist aviation air quality practitioners in preparing an emissions inventory of organic gases (OGs) emitted by aircraft equipped with turbofan, turbojet, and turboprop engines.
- Aircraft Engine Speciated Organic Gases: Speciation of Unburned Organic Gases in Aircraft Exhaust (PDF) (27 pp, 613K, EPA-420-R-09-902, May 2009) - Technical Support Document
  Provides the scientific details of the various datasets that were evaluated during the development of the aircraft-related OG speciation profile. The Technical Support Document (TSD) is supported by the Technical Support Spreadsheet listed below.
- Aircraft Engine Speciated Hydrocarbons (Turbofan, Turbojet, and Turboprop Engines) (XLS) (3 pp, 928K, EPA-420-R-09-903, May 2009) - Technical Support Spreadsheet
  This spreadsheet provides the technical data, algorithms, and computations used to derive the speciated OG profile.
- Quality Assurance Project Plan for the Development of a Commercial Aircraft Hazardous Air Pollutants Emission Inventory Methodology (PDF) (21 pp, 287K, EPA-420-R-09-904, May 2009)
  Outlines the procedures and datasets used to develop the data and methodology provided/discussed in the Recommended Best Practice (RBP).
Final Rule: Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures (published November 17, 2005)
EPA is amending the existing emission standards for oxides of nitrogen (NOx) for new commercial aircraft engines. These standards are equivalent to the NOx emission standards of the United Nations International Civil Aviation Organization (ICAO), and thereby will bring United States aircraft standards into alignment with the international standards. These standards will go into effect on December 19, 2005 and they will apply to new aircraft engines utilized on commercial aircraft that include small regional jets, single-aisle aircraft, twin-aisle aircraft, and 747s and larger aircraft.
- Fact Sheet: Aircraft Engine Emission Standards (PDF) (3 pp, 51K, EPA420-F-05-015, November 2005)
- Final Rule (PDF) (24 pp, 240K, published November 17, 2005)
- Correction (typographical) to Final Rule (PDF) (1 pp, 40K, published November 25, 2005)
- Emission Standards and Test Procedures for Aircraft and Aircraft Engines: Summary and Analysis of Comments (PDF) (55 pp, 477K, EPA420-R-05-004, November 2005)
Evaluation of Air Pollutant Emissions from Subsonic Commercial Jet Aircraft (PDF) (77 pp, 412K, EPA420-R-99-013, April 1999)
Direct Final Rule: Aircraft Emission Standards Harmonizes US Aircraft Standards with International Standards (published May 8, 1997)
- Fact Sheet: Adopted Aircraft Engine Emission Standards (PDF) (5 pp, 17K, EPA420-F-97-010, April 1997)
- Direct Final Rule (PDF) (12 pp, 236K, published May 8, 1997)
- Regulatory Support Document (PDF) (25 pp, 81K, February 1997)
Draft Technical Data to Support FAA Advisory Circular on Reducing Emissions from Commercial Aviation (September 1995)
- Abstract (TXT) (12K, September 1995)
- Report (PDF) (76 pp, 276K, September 1995)
- Appendices (PDF) (33 pp, 221K)

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Lead Emissions from Piston-Engine Aircraft Using Leaded Aviation Gasoline

The EPA is evaluating the impact of lead emissions from aircraft using leaded aviation gasoline in order to make a determination regarding whether aircraft lead emissions cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare. These actions are in response to petitioners’ requests, which are provided below along with the EPA responses to date. The EPA currently intends to issue a proposed finding on the question of endangerment in 2017. This proposed finding will then undergo public notice and comment. After evaluating comments on the proposal, we plan to issue a final endangerment finding in 2018. Documents and information relevant to the EPA’s ongoing evaluation and other EPA activities regarding lead in air are provided below.

EPA Response Memorandum to the 2014 Petition from Friends of the Earth, Physicians for Social Responsibility, and Oregon Aviation Watch Regarding Lead Emissions from Piston-Engine Aircraft (PDF) (2 pp, 644K, January 2015)
Petition from Friends of the Earth, Physicians for Social Responsibility, and Oregon Aviation Watch (PDF) (20 pp, 270K, April 21, 2014) This petition requests that the Administrator reconsider EPA’s July 18, 2012, response to Friends of the Earth’s October 3, 2006, petition for rulemaking seeking the regulation of lead emissions from general aviation aircraft. It also requests the Administrator regulate lead emissions from general aviation aircraft.
EPA Response Memorandum to the 2006 Petition from Friends of the Earth Regarding Lead Emissions from Piston-Engine Aircraft (PDF) (20 pp, 9.96MB, July 2012)
- Fact Sheet: EPA Response to the 2006 Petition from Friends of the Earth Regarding Lead Emissions from Piston-Engine Aircraft (PDF) (2 pp, 135K, EPA-420-F-12-050, July 2012)
Advance Notice of Proposed Rulemaking on Lead Emissions from Piston-Engine Aircraft Using Leaded Aviation Gasoline (PDF) (30 pp, 702K, published April 28, 2010)
- Fact Sheet: Lead Emissions from Piston Engine Aircraft Using Leaded Aviation Gasoline (PDF) (3 pp, 560K, EPA-420-F-10-013, April 2010)
- Extension of Comment Period (PDF) (2 pp, 57K, published June 24, 2010) EPA extended the comment period by an additional 60 days for the “Advance Notice of Proposed Rulemaking on Lead Emissions from Piston-Engine Aircraft Using Leaded Aviation Gasoline.”
Request for Public Comment on Petition to Limit Lead Emissions from General Aviation Aircraft (PDF) ( 4 pp, 153K, published November 16, 2007) In 2007, EPA issued a notice requesting public comment and information related to a wide range of issues regarding exposure to lead from combustion of leaded aviation gasoline, emissions of lead, fuel options, and piston-engine technology. The comments received to date are publicly available in the docket (EPA-HQ-OAR-2007-0294).
Petition from Friends of the Earth (PDF) (12 pp, 303K, October 3, 2006) This petition requests that the Administrator find that aircraft lead emissions cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare, and that EPA regulate those emissions.

In separate activities related to the National Ambient Air Quality Standards for lead, EPA finalized revisions to the ambient monitoring requirements for measuring lead in the air on December 14, 2010. These amendments expanded the nation's lead monitoring network to better assess compliance with the 2008 National Ambient Air Quality Standards for lead. EPA required the continuation of monitoring at airports emitting at least one ton of lead per year. EPA also required the states to conduct a year-long monitoring study at 15 airports that emit less than one ton per year to determine how these sources impact air quality.

Fact Sheet: Program Overview on Airport Lead Monitoring (PDF) (4 pp, 215K, EPA-420-F-15-003, January 2015) This Program Summary provides a final summary of the data on concentrations of lead measured at 17 airport facilities in the U.S.
Fact Sheet: Program Update on Airport Lead Monitoring (PDF) (4 pp, 210K, EPA-420-F-13-032, June 2013) This Program Update provided a summary of the data on concentrations of lead measured at 17 airport facilities in the U.S.
Selection of Airports for the Airport Monitoring Study (PDF) (40 pp, 14MB, November 18, 2010) This document describes EPA’s selection of the 15 airports included in the airport lead monitoring study.

The following documents provide information on inventory documentation and additional data:

Calculating Piston-Engine Aircraft Airport Inventories for Lead for the 2008 National Emissions Inventory (PDF) (22 pp, 738K, EPA-420-B-10-044, December 23, 2010) This Technical Support Document (TSD) provides the most recent methodology used to estimate airport-specific lead emissions for the 2008 National Emissions Inventory (NEI). The 2008 NEI can be accessed from EPA’s 2008 National Emissions Inventory Data & Documentation website.
Development and Evaluation of an Air Quality Modeling Approach for Lead Emissions from Piston-Engine Aircraft Operating on Leaded Aviation Gasoline (PDF) (86 pp, 6.5MB, EPA-420-R-10-007, February 2010) This final report presents the results of EPA's study to develop a modeling approach to quantify how emissions from piston-engine aircraft affect ambient lead levels at the local scale.
- Appendix A (PDF) (50 pp, 1.3MB)
- Appendix B (PDF) (14 pp, 165K)
- Appendix C (PDF) (12 pp, 2.1MB)
- Appendix D (PDF) (14 pp, 2.1MB)
- Appendix E (PDF) (14 pp, 7.6MB)
- Appendix F (PDF) (18 pp, 10.7MB)