ACRP Report 149: Improving Ground Support Equipment Operational Data for Airport Emissions Modeling is a guidance document that provides a potential update to the current set of default Ground Service Equipment (GSE) fleet and activity data used for passenger and cargo aircraft and a protocol to improve the accuracy and consistency of data collection for airport GSE activity compatible with Emissions and Dispersion Modeling System (EDMS), and the Aviation Environmental Design Tool (AEDT). This guidance document can be used by airport operations, environmental and planning personnel, and other stakeholders for the purpose of understanding and improving local air quality.
The updated set of default GSE fleet and activity values address the number and type of vehicles by aircraft code (e.g., A, B, C, D, etc.); difference between type of operations (i.e., dedicated cargo vs. passenger operations); time in operational mode (including idling); and gate deicing vehicles. The airport-specific data-gathering protocol includes the parameters (i.e., time in operational mode, climatic conditions) to be collected; recommendation of statistically valid sample sizes; operational considerations for start-up and mobilization of equipment (i.e., when is the equipment actually in use for the aircraft or in transit); coordination with airlines; and safety considerations. The guidance is tailored to airports of different sizes (small, medium, large/international); airports of different climates; limitations of the current default GSE fleet; various fueling methods (e.g., hydrant system vs. fuel trucks); availability and utilization of aircraft parking position utilities (availability of ground power and pre-conditioned air); and is applicable to newer aircraft (i.e., A380, B787).
Estimating an airport’s contribution to a region’s overall air quality is often required for State Implementation Plans (SIPs), Health Risk Assessments (HRA), National Environmental Policy Act (NEPA) analyses, other emission inventory programs, and for grant applications, such as FAA’s Voluntary Airport Low Emissions (VALE) program.
Although airport GSE can provide significant contributions to an airport’s overall emissions, little guidance is available to help airports accurately capture actual GSE activity at their facilities in a manner suitable for the FAA’s approved emissions models, EDMS and the AEDT. This can result in inaccurate predictions of air quality impacts because staff may use insufficient or inconsistent data collection, analysis, and reporting methods (for example, when GSE are considered to be within an aircraft’s activity zone). Conversely, airports often choose not to collect specific GSE activity data and instead use default values established in EDMS and AEDT, often due to resource constraints and the lack of guidance on how to gather GSE activity data. However, these default values are widely acknowledged to be conservative and may overestimate an airport’s air quality impacts.
Under ACRP Project 2-46, research was conducted by KB Environmental Sciences, Inc. in association with CDM Smith, Mosaic, ATAC, and Jim Gebhardt. A total of 65 airlines, ground handling companies, and equipment manufacturers were contacted to gain insight on their fleet, operations, environmental initiatives, and willingness/ability to share information and participation in the project.