Evaluations of Conflict Probe Alert Reliability Requirements

Full Text: PDF icon Pdf (3.02 MB)
Document Number:
Publication Date:
Authors: Robert A. Bastholm, Spectrum Software Technology, Inc.
Thomas Fincannon, Ph.D., Applied Research Associates, Inc.
Anthony J. Masalonis, Ph.D., Spectrum Software Technology, Inc.
George M. Puzen, Spectrum Software Technology, Inc.
Ben Willems

Willems, B., Masalonis, A. J., Fincannon, T., Puzen, G. M., & Bastholm, R. A. (2016). Separation management human-in-the-loop simulation: Evaluations of conflict probe alert reliability requirements and conflict probe algorithmic improvements (DOT/FAA/TC-16/38). Atlantic City International Airport, NJ: Federal Aviation Administration William J. Hughes Technical Center.


Objective: The purpose of this study is to assess the impact of factors that influence Conflict Probe (CP) Alert reliability (i.e., conformance bound settings, algorithmic enhancements, and radar surveillance noise) and display location (RA-Side vs. R- and RA-Side) on controller performance, attitude, and behavior. Background: This is the third in a series of studies examining how different automation and display characteristics impact a controller’s ability to maintain separation between aircraft. The CP has emerged as an important tool to maintain separation. The current study examines how CP Alert reliability and display location impact a controller’s ability to manage conflicts in a busy airspace. Method: Eight air traffic controllers participated in the experiment. The participants completed 12 sessions to examine the impact of algorithmic enhancements, radar surveillance noise, conformance bound and likelihood settings that determine which potential conflicts generate alerts at what timing, and CP display location. Because of technical limitations, conformance bound and likelihood settings did not vary across any of the conditions. Results: In spite of the aforementioned technical problems, which caused controllers to use a CP with a low level of alert reliability, controllers used the R-Side CP displays, and we identified a combined advantage of displaying the CP on the R-Side with algorithmic enhancements. The analysis of performance and subjective ratings indicated (a) that controllers only used the CP when it was on the R-Side; (b) that when the CP was available on the R-Side, it did improve controller performance; and (c) that controllers found the excess of yellow alerts in the Legacy (no algorithmic enhancements) condition to be a nuisance and a distraction from their tasks.Conclusion: Even at the lower levels of CP Alert reliability, which we inadvertently presented in more runs than intended, controllers accept CP functionality on the R-Side, and it provides some benefit. If R-Side CP is fielded with algorithmic enhancements and the current or better parameter settings, we expect acceptance and utility. Future research may need to consider the potential benefits of using a buffer zone to present near-conflicts to controllers. Applications: An R-Side CP that presents only red alerts will likely enhance controller performance, and controllers will likely accept it. Yellow alerts may represent information overload, but controllers indicate a need for some information about near-losses of separation. Future research may need to consider the potential benefits of using a buffer zone to present a limited number of near-conflicts.