This AIR describes procedures for calculating emissions resulting from the main engines of commercial jet and turboprop aircraft through all modes of operation for all segments of a flight. Piston engine aircraft emissions are not included in this AIR. Some information about piston engine aircraft emissions can be found in FOCA 2007. The principal purpose of the procedures is to assist model developers in calculating aircraft emissions in a consistent and accurate manner that can be used to address various environmental assessments including those related to policy decisions and regulatory requirements.

The pollutants considered in this document are:

•Nitrogen Oxides (NOx)

•Carbon Monoxide (CO)

•Total unburned Hydrocarbons (THC)

•Carbon Dioxide (CO₂)

•Water (H₂O)

•Sulfur Oxides (SOx)

•Volatile Organic Compounds (VOC)

•Methane (CH₄)

•Non-Methane Hydrocarbons (NMHC)

•Non-Methane Volatile Organic Compounds (NMVOC)

•Nitrous Oxide (N₂O)

•Particulate Matter (PM_2.5 and PM₁₀)

As indicated above, hazardous air pollutants (HAPs) are not individually accounted for; many of these are simply included as part of THC. Also, trace metals are not included other than those that may already be accounted for as part of PM emissions. Since the scope is limited to aircraft engine emissions only, emissions from Ground Service Equipment (GSE), roadway vehicles, power plants, training fires, etc., are not included within this document. Athough Auxilliary Power Units (APU), brakes, and tires are also part of the aircraft, their emissions (e.g., tire wear) are not within the scope of this document.

The methods are based on aircraft performance and emissions modeling. This means that only the pollutants exiting the exhaust of an engine are considered. Any atmospheric effects including those that occur in the near-field (e.g., exhaust plume) and the subsequent atmospheric dispersion are not modeled. The exception to this is in the computation of PM emissions.