What are FAA's Environmental Goals?
FAA seeks to work with local governments and airspace users to provide capacity in the United States airspace system that meets projected demand in an environmentally sound manner. FAA is also supporting the Next Generation Air Transportation System (NextGen) Joint Planning and Development Office (JPDO) as it seeks to promote environmental stewardship by reducing significant noise and emissions impacts in absolute terms and balancing aviation's environmental impact with other societal objectives.
What is the role of FAA's environmental analysis tools research, development and implementation efforts?
The role of FAA's effort is to conduct research and develop, verify, and validate analytical tools to better understand the relationship between noise and emissions and different types of emissions, and to provide the cost benefit analysis capability necessary for data-driven decision making. This is an integral part of FAA's Flight Plan and the NextGen implementation plan.
Who is responsible for developing and supporting FAA's environmental analyses tools?

The FAA's Office of Environment and Energy (AEE) has overall responsibility for developing analyses tools to assess and help mitigate aviation's environmental impact. The AEDT development team consists of:

The EDS development team consists of:

The APMT development team consists of:

Integrated Noise Model (INM)

What is the INM?
The INM is a computer model that evaluates aircraft noise impacts in the vicinity of airports.
What are the uses of INM?
In the United States, the model is typically used for FAR Part 150 noise compatibility planning and for FAA Order 1050 environmental assessments and environmental impact statements. The INM has many analytical uses, such as:
  • Assessing current aircraft noise impacts around a given airport or heliport
  • Assessing changes in noise impact resulting from new or extended runways or runway configurations
  • Assessing changes in noise impact resulting from new traffic demand and fleet mix
  • Evaluating noise impacts from new operational procedures
  • Evaluating noise impacts from aircraft operations in and around National Parks
Who is the developer of the INM?
The INM model is developed and maintained by:
  • FAA Office of Environment and Energy (AEE-100) — project management
  • ATAC Corporation — system integration, user interface, and flight model
  • Volpe National Transportation Systems Center (VNTSC) — noise model
Who has access to the INM?
The INM is available to the general public, and currently has over 1,000 users in 64 countries.
What are the plans for INM in the future?
Version 7.0 is expected to be the last major release of INM. INM version 7.0d was released in June 2013. Version 2b will replace INM when it is released.
What is the appropriate substitution aircraft for an [insert aircraft type] aircraft in INM?
The only pre-approved substitution aircraft for use within INM studies can be found under Setup // Substitutions within the INM interface. Beyond those substitution aircraft included within INM, FAA leaves it up to the INM user performing a noise study to choose the most appropriate substitution for a given aircraft. Only the analyst performing the INM study has the detailed knowledge of the purpose for and intended use of the study's results, specifics about fleet mix and operational details at the airport being modeled, and so on, required to make the best substitution choice within a given situation. When non-standard aircraft substitutions in INM are utilized for FAA-funded projects, they must be approved by the FAA Office of Environment and Energy (AEE).
Can the INM be used to model small airports or airplanes?
Yes, although the INM's database does not include the same level of coverage for smaller aircraft as it does for the larger commercial aircraft fleet. There are no limits within the INM in terms of airport layout/size, number of operations, or fleet mix.
Are there training courses provided for the INM?
The FAA does not require that a user go through formal training in order to conduct INM studies, and does not provide training on the use of the INM, as the supplied documentation is often sufficient for most modeling purposes. There are commercial training courses for the INM available which can readily be found via the Internet.
Can the INM model helicopters?
INM version 7.0 contains extensive helicopter modeling capabilities, based on FAA's Heliport Noise Model (HNM) Version 2.2. This includes helicopter-specific noise data and directivity implementation, and expanded helicopter operational modeling functionality (including helicopter-specific operational modes such as hover or idle). Twenty-six different helicopters are represented in the INM version 7.0d database.
Is the current version of the INM compliant with ECAC Doc. 29?
INM version 7.0 is compatible with the methodologies contained in ECAC.CEAC Doc. 29 3rd edition (2005). Previous versions of INM complied with the methodologies contained in ECAC.CEAC Doc. 29, 2nd Edition (1997).
Is there a student/educational version of the INM or a discount available?
There is only one publicly available version of the INM, charged at a minimal fee (i.e. US$300 for INM7.0). The fee is to cover the cost associated with the distribution of the software and technical support, and there are no further discounts available.
Can you create new aircraft, flight profiles, and/or noise data within the INM?
The INM allows for the creation of user-defined data to represent most aspects of an INM study including basic aircraft data, flight profile definitions, and aircraft source noise data. The INM User's Guide and Technical Manual fully describe these types of data, as well as requirements for the use of user-defined aircraft data within federally sponsored noise analyses.
Is there a callable version of the INM that can be incorporated within other software?
There is no publicly available callable version of the INM.
Why are the noise contours generated by my INM study oddly shaped or asymmetrical?
The shape of INM noise contours depends on numerous factors; such as study geometry, terrain, flight operations (including bank angle), and source directivity (for helicopters). Any one of these factors (or combination thereof) can result in asymmetrical noise contours.

Furthermore, the shape of INM noise contours can be influenced by the resolution of the underlying contour grid, specifically a large spacing between contour grid points can result in abnormally shaped/asymmetrical contours. It is especially important to ensure adequate contour grid resolution when dealing with small noise contours. Information on changing the resolution of contour grids within the INM can be found on page 236 of the INM 7.0 User's Guide.
What coordinate system/map projection method does the INM use?
The INM uses a conic projection using the WGS-84 spheroid and is described in Appendix L of the INM 7.0 User's Guide. The standard airport, runway, navaid, and fix location data included with the INM use the NAD83 datum.

Noise Integrated Routing System (NIRS)

What is NIRS?
The Noise Integrated Routing System (NIRS) is a noise-assessment program designed to provide an analysis of air traffic changes over broad areas. The NIRS Screening Tool (NST) was created as a companion to NIRS to assist in screening proposed air traffic airspace and procedure changes to determine any potential to increase noise levels over communities beneath the aircraft route. NIRS was replaced by AEDT version 2a in March of 2012. NST has been replaced by the Aviation Environmental Screening Tool (AEST).
What are NIRS noise computations based on?
NIRS is based on the same core noise computations that are developed for the INM.

Emissions and Dispersion Modeling System (EDMS)

What is EDMS?
The Emissions and Dispersion Modeling System (EDMS) is designed to assess the air quality impacts of airport emission sources, including both aircraft and non-aircraft related sources.

In 1998, FAA identified EDMS as the required model to perform air quality analyses for aviation sources, and mandated that an environmental impact analysis using EDMS be completed before any changes to airports are made.

The aviation emission algorithms and data used in EDMS also are well established and are developed and/or recommended by the U.S. Environmental Protection Agency, which since 1993 has declared EDMS the "Preferred Guideline" model for use in civil airports and military air bases.
What emission sources are modeled in EDMS?
EDMS models aircraft-related sources such as aircraft engines, auxiliary power units and ground support equipment. EDMS also models airport emission sources that are not aircraft-specific, such as ground access vehicles, stationary sources, construction equipment, and training fires that may occur at the airport.
What pollutants are modeled in EDMS?
The pollutants modeled in EDMS include Carbon Monoxide (CO), Total Hydrocarbons (THC), Non-Methane Hydrocarbons (NMHC), Volatile Organic Compounds (VOC), Sulfur Oxides (SOx), Nitrogen Oxides (NOx), Particulate Matter (PM-2.5 & PM-10) and speciated organic gases (OGs) including known hazardous air pollutants (HAPs).
Who are the users of EDMS and how many are there?
There are currently over 700 users of EDMS worldwide. Users of EDMS include airport authorities, environmental consulting firms, and government agencies throughout the world interested in evaluating the emissions released at airports.
Who develops EDMS?
Since 1995, CSSI has developed and maintained EDMS, which was originally developed in the mid-1980s as a complex source model capable of assessing air quality impacts due to airport development. In 1997, CSSI completely re-engineered EDMS to meet both scientific and policy related needs, and benefit from data and methodology advances.
Where can I find more information on EDMS?
More information on EDMS, including how to order a copy of an installation CD and how to obtain technical support can be found at the EDMS Model Page. In addition, general inquiries can be directed to FAA by phone at (202) 267-7821 or to CSSI at
What is the latest released version of EDMS?
Version (released August 2013) is the current latest version released.
What will be the next released version and what changes will be included?
There will be no further releases of EDMS. AEDT version 2b, when released, will replace EDMS.
What EPA tools are incorporated into EDMS?
EDMS is one of the few air quality assessment tools specifically engineered for the aviation community. It includes the latest aircraft engine emission factors from the International Civil Aviation Organization (ICAO) engine exhaust emissions databank, on-road vehicle emission factors from the latest version of the Environmental Protection Agency's (EPA) MOBILE6 model, and the EPA's NONROAD model for ground support and construction equipment. In addition, EDMS uses the EPA-validated AERMOD dispersion model.
How does EDMS calculate emissions inventories?
EDMS can be used to create an emissions inventory for any individual airport emission source or combination of emission sources. To create an aircraft emissions inventory, the modeler inputs the aircraft fleet present at an airport and the annual number of landing and takeoff (LTO) cycles for each aircraft or a schedule. The modeler can specify each aircraft's taxi and queue time, as well as the takeoff weight and approach glide slope angle, which are used to determine the takeoff, climb out and approach time in mode (TIM) values. The takeoff, climb out, and approach TIM values in EDMS's internal database originate from methodology presented in the Society of Automotive Engineers (SAE) Aerospace Information Report (AIR) 1845 and account for aircraft-engine specific performance. Similar to aircraft, the modeler has the ability to define and include the adjunct APU and GSE activity, roadway traffic, parking lot throughput, and stationary source and training fire operations.
How does EDMS calculate emissions dispersion?
For dispersion analyses, EDMS generates input files to be processed by EPA's AERMOD. The manner in which AERMOD is employed in EDMS is based on guidance from the American Meteorological Society/USEPA Regulatory Model Improvement Committee (AERMIC), which is responsible for developing AERMOD and introducing state-of-the-art modeling concepts into EPA local-scale air quality models.

Because AERMOD requires both surface and upper air meteorological data, AERMET is also bundled with EDMS. AERMET is AERMOD's meteorological preprocessor which transforms many different formats of "raw" weather data into an "AERMOD-ready" format. Similar to AERMOD, AERMET can be run either internally or externally to EDMS. EDMS also includes an interface to AERMAP, the terrain preprocessor for AERMOD. Once the dispersion analysis is initiated within EDMS, the execution and control of AERMET, AERMAP and AERMOD is entirely transparent to the user.

Aviation Environment Design Tool (AEDT)

What is AEDT?
AEDT is a comprehensive suite of software tools that enable thorough assessment of the environmental effects of aviation. AEDT allows for the assessment of interdependencies between aviation-related noise and emissions. AEDT consists of the integration and harmonization of existing analysis tools, including the Integrated Noise Model (INM — local noise analysis), the Emissions and Dispersion Modeling System (EDMS – local emissions analysis), and the Noise Integrated Routing System (NIRS – noise analysis of air traffic airspace and procedure actions. The Aviation Environmental Screening Tool (AEST) uses AEDT to assist the FAA in screening proposed air traffic airspace and procedure changes for any potential to increase noise levels over communities beneath the aircraft route.
When will AEDT be released?
AEDT version 2a, which replaced NIRS, is available to the public now at the AEDT website. AEST has replaced the NIRS Screening Tool (NST). AEDT version 2b will replace INM and EDMS when it is released. Please go to the AEDT website for status updates on AEDT development. AEST is only available to FAA employees. For information on AEST, please contact the ATO Environmental Program Group.
Who develops AEDT?
The AEDT Development Team consists of:
Who uses AEDT?
AEDT has a wide range of users including domestic and international regulatory bodies, airports, consultants, academia, environmental organizations, and industry organizations, as well as airframe and engine manufacturers. AEDT is currently used by the U.S. government to consider the interdependencies between aircraft-related fuel burn, noise and emissions.

Environmental Design Space (EDS)

What is EDS?
The Environmental Design Space (EDS) is an aircraft systems model that integrates engine and aircraft design with aircraft operations to examine environmental performance and technology development providing aircraft data to AEDT and cost data to APMT.
When will EDS be released?
There are currently no plans to release EDS to the general public. The intent is to use EDS in the CAEP and JPDO processes. Due to the nature of some of the EDS components EDS "aircraft" will be provided in the form of surrogate models.
Who develops EDS?
The EDS Development Team consists of the Georgia Institute of Technology and the Massachusetts Institute of Technology under the auspices of the FAA/Transport Canada/NASA-sponsored PARTNER Center of Excellence.
Who uses EDS?
EDS is currently being developed for FAA/AEE with the goal of supporting the CAEP/8 analysis cycle. It is intended that EDS will be used in conjunction with both APMT and AEDT. Further, EDS is also intended for use in future technology goals assessment for NextGen.

Aviation Environmental Portfolio Management Tool (APMT)

What is APMT?
APMT is the Aviation Environmental Portfolio Management Tool (APMT), which provides the environmental impact and economic analysis capability, and works with AEDT and EDS to more effectively assess and communicate environmental effects, interrelationships, and economic consequences based on integrated analyses.
When will APMT be released?
APMT is currently a research model that is not available to the general public. The current research focus of the tool and the large database sizes (terabytes of data) do not allow for desktop usage of the model. APMT, however, is available to support FAA and ICAO/CAEP research activities, with the APMT development team running the model.
Who develops APMT?
The APMT development team consists of The Team works under the auspices of the FAA/Transport Canada/NASA-sponsored PARTNER Center of Excellence.
Who uses APMT?
APMT is being developed for FAA/AEE to supporting the FAA domestic analyses and ICAO CAEP analyses, in conjunction with EDS and AEDT.

Integrated New Tool Suite

The tool suite sounds very complicated, what is AEE doing to mitigate risk?
AEE is using a "spiral development" approach. Deliverables are sequenced in a logical way by setting clear, aspirational long-term goals and short-term (annual) deliverable so that continuous improvements are benchmarked and if funding stops, we will have usable products that are better than the baseline.
When will the new tool suite be available?
The new tool suite is in use now. Versions of EDS, AEDT, and APMT have been available to support CAEP analyses since CAEP/8 (starting in 2007). EDS and APMT will have transparent methodologies but are not expected to be publicly available. AEDT version 2a, which replaced NIRS, is publicly available now, and AEDT 2b will replace INM and EDMS when it is released. With AEDT 2b users will be able to conduct integrated noise and emissions assessments.