Fighter Index of Thermal Stress: Relation to Weather Conditions at ATC and TAC Bases

Abstract : The Fighter Index of Thermal Stress (FITS) is a tool recently developed for minimizing hazardous aircrew heat stress during hot-weather operations. The FITS table, entered with ground dry bulb temperature (Tdb) and dewpoint temperature (Tdp), yields a numerical estimate of cockpit heat stress. Superimposed on the table are Normal, Caution, and Danger Zones, with footnotes recommending appropriate precautions. This report examines the relationship of FITS to typical weather conditions at 30 ATC and TAC bases in the continental United States. An appendix presents a graph for each base, indicating the frequency of readings in the Caution and Danger Zones for each hour of the day and month of the year.