## APPENDIX A3 - Ground Support Equipment Emissions Inventory for Criteria Pollutants 

## A3.1 Overview 

This appendix discusses the methodologies for computing emissions from ground support equipment (GSE). GSE is a term used to describe the vehicles that service aircraft after arrival and before departure (i.e., while aircraft are unloading and loading passenger s and/or freight). Emissions from these sources are based on the number and type of equipment used to service each aircraft along with the amount of time the equipment is in use per aircraft landing -takeoff (LTO) cycle and the equipment fuel type. 

There are a wide variety of GSE that service aircraft; a list of the most common GSE types, along with a brief description, follows: 

• Air Start Units — Provide large volumes of compressed air to an aircraft’s main engines for starting. Air start units are also called air compressors. 

• Air Conditioning Units — Provide conditioned air to ventilate and cool parked aircraft. 

• Aircraft Tugs/Tractors — Tow aircraft in the terminal gate area or on the tarmac. They also tow aircraft to and from hangers for maintenance. These are broken into two categories: tugs/tractors for narrow body aircraft and tugs/tractors for wide body aircraft. 

• Baggage Tugs/Tractors — Equipment used at airports to haul baggage between the aircraft and the terminal. 

• Belt Loaders — Mobile conveyor belts used at airports to move baggage between the ground and the aircraft hold. 

• Buses — Shuttle personnel between facility locations. 

• Cargo Moving Equipment — Variety of types of equipment employed to move baggage and other cargo around the facility and to and from aircraft. This category includes forklifts, lifts, and cargo loaders. 

• Deicers — Vehicles used to transport, heat, and spray deicing fluid. 

• Ground Heaters — Mobile units that provide heated air to heat the parked aircraft. 

• Ground Power Unit (GPU) — Mobile ground-based generator units that supply aircraft with electricity while they are parked at the facility. GPUs also are called generators. 

• Light Carts — Mobile carts that provide light. 

• Other — Small miscellaneous types of equipment commonly found at facilities such as compressors, scrubbers, sweepers, and specialized units. 

• Pickups — Move personnel and equipment around the facility. 

