Metabolic Rate and Heat Stress Associated With Flying Military Rotary-Wing Aircraft.

Abstract

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, This report focuses on the metabolic rates of front-and rear-seated crewmembers operating military rotary-wing aircraft. A review of the literature was performed and summarized to include U.S. Army and NATO aircraft. Based on the findings of this report, piloting such aircraft requires very light to light metabolic intensities (105-240 watts). Preflight activities and crewmember duties are considered moderate metabolic intensity (206-490 watts). The operational scenario for military aviators is described along with a brief explanation of U.S. Army helicopters including a summary of general crewmember tasks. Since heat stress is a limiting factor in the helicopter cockpit, a summary of temperature data is also included. Although temperature control devices have shown some success in alleviating heat stress in the cockpit, there is still evidence of decrements in aviator performance mainly due to wearing impermeable chemical protective clothing. SUBJECT TERMS EXECUTIVE SUMMARYThis report focuses on the metabolic rates of front-and rear-seated crewmembers operating military rotary-wing aircraft. A review of the literature was performed and summarized to include U.S. Army and NATO aircraft. Based on the findings of this report, piloting such aircraft requires very light to light metabolic intensities (105-240 watts). Preflight activities and crewmember duties are considered moderate metabolic intensity (206-490 watts). The operational scenario for military aviators is described along with a brief explanation of U.S. Army helicopters including a summary of general crewmember tasks. Since heat stress is a limiting factor in the helicopter cockpit, a summary of temperature data is also included. Although temperature control devices have shown some success in alleviating heat stress in the cockpit, there is still evidence of decrements in aviator performance mainly due to wearing impermeable chemical protective clothing.

The maximum evaporative potential of constant wear immersion suits influences the risk of excessive heat strain for helicopter aircrew

“…The recommendations of the present study are primarily focused on the flight scenario assessed, which included a 20 min pre-flight period of moderate intensity work (350 Watts) and up to 240 min flight period of low intensity work (150 Watts). These assumptions reflect the likely work intensity and metabolic rates of aircrew performing their routine duties [ 11 , 30 – 32 ]. However it needs to be acknowledged that deviations from these assumptions, such as longer pre-flight checks or greater metabolic rates during flight, would likely cause greater heat strain than the findings presented here.…”

“…Metabolic rates were selected to represent typical work rates during the pre-flight and flight periods. Research has shown the work rate of rotary-wing aircraft pilots to be of a low intensity during flight, ranging between 100–240 W [ 11 , 32 , 33 ]. The pre-flight activities are generally of a moderate work intensity, with metabolic rates up to 206–490 W [ 11 , 32 ].…”

“…Research has shown the work rate of rotary-wing aircraft pilots to be of a low intensity during flight, ranging between 100–240 W [ 11 , 32 , 33 ]. The pre-flight activities are generally of a moderate work intensity, with metabolic rates up to 206–490 W [ 11 , 32 ]. Therefore metabolic rates included in the modelling were 350 W for pre-flight activities and 150 W during flight.…”