Technology Assessment to Improve Operations Counts at Non-Towered Airports
Accurate airport operations counts are important for determining appropriate funding allocations for airport development and improvement. However, fewer than 270 of the 2941 non-primary airports in the United States have air traffic control personnel who are available to count airport operations. Existing counting methods, such as automatic acoustic counters, are not viable long-term solutions because of the expense and inconvenience of deploying the devices on a large scale.
The Federal Aviation Administration (FAA) Planning and Environmental Division tasked the FAA Airport Technology Research and Development Branch with the evaluation of aircraft transponder technology to accurately register operations counts at non-towered airports. The evaluation was conducted Purdue University through the FAA Partnership to Enhance General Aviation Safety, Accessibility and Sustainability Center of Excellence. This report documents the research conducted at four Indiana airports to validate a cost-effective counting technology based on a technique that uses signal strength obtained from aircraft transponders to register the occurrence of aircraft operations at non-towered airports. This report also presents and validates a barometric calibration method, which is used to improve the accuracy of operations counts.
Data collectors were installed at Purdue University Airport, Terre Haute Regional Airport, Indianapolis Executive Airport, and Warsaw Municipal Airport, providing over 150 million transponder records during the data collection period. Operations counts estimates were compared to Air Traffic Activity Data System counts where available, resulting in monthly error rates ranging from -8.7% to 8.3% and long-term error rates ranging from -3.1% to 3.0% over time periods ranging from 31 days to 398 days. These results suggest that this implementation of the transponder signal-counting technology is an accurate and cost-effective way to count non-towered airport operations. Improvements and testing of this technology are being undertaken.
DOT/FAA/TC-19/43
Authors: John H. Mott, Chuyang Yang, Brandon Hardin, Steven Zehr, Darcy M. Bullock, Jack R. Bell