Flight performance effects of thermal stress and two aviator uniforms in a UH-60 helicopter simulator

The effects on flight performance of the four combinations of an unencumbered mission oriented protective posture (MOPP) aviator battle dress uniform (ABDU) and encumbered MOPP4 over ABDU flight ensemble in cool (70 degrees F or 21.1 degrees C, 50% relative humidity [RH]) and hot (100 degrees F or 37.8 degrees C, 50% RH) UH-60 simulator cockpit conditions were evaluated with a repeated measures, 2 x 2 factorial study using nine crews. The encumbered MOPP4 uniform had the most frequent adverse effect on flight performance followed by heat stress, with less frequent effects from the combination or interaction of these two factors. This study confirmed that heat stress and wearing an encumbered U.S. Army MOPP4 flight uniform significantly reduced endurance and flight performance in a UH-60 simulator.