One of the most exciting areas of current aerial application technology is the use of global positioning (in particular, differential GPS) to provide a real-time image of the position of a spray aircraft during spray operation. Current hardware range from simple systems that keep track of the aircraft flight path (for later playback), to more sophisticated aircraft navigational systems that provide a means for the pilot to correct the aircraft flight path while spraying (continuous feedback). One addition expected to these systems is access to a very fast version of the USDA Forest Service aerial application prediction model FSCBG (Forest Service Cramer-Barry-Grim). This version of the model (FSCBG/RT) will run in real time on the on-board computer, and will access application rate, meteorological parameters, release height, and aircraft direction, to predict the effects of aircraft speed, flight profile, pump pressure changes, flow rate, and other data, on the spray plume. This prediction will be returned to the navigation and monitoring system for possible corrective action. The end product will be a system that will track the aircraft, display the spray swath width, and visualize the pesticide spray deposition and movement, all in real time. This paper reviews the need for a GPS/GIS tracking system in the aerial application of pesticides, highlights the field evaluation of these devices by the USDA Forest Service, summarizes the development of the FSCBG/RT model, visualizes how the model will interact with real-time data, and anticipates its potential for decision-making, environmental monitoring and accounting, tracking, and documentation.