Relationships between ambient, cockpit, and pilot temperatures during routine air operations.

Thermal data obtained from aircraft flying routine sorties from RAF Germany in summer have been reduced to a form suitable for statistical analysis by describing thermal stress in terms of a modified wet bulb globe temperature (WBGT) index, and thermal strain in terms of mean body temperature (Tb). Ambient temperature could be related to cockpit temperature, and cockpit temperature to pilot Tb, by linear equations of positive slope. Relationships between Tb and sortie time could be represented by exponential equations. The relationships between cockpit temperature and sortie time could also, in fixed-wing aircraft, be described by exponential equations, although in helicopters the relationships were better described by linear equations of negative slope. Models capable of predicting cockpit thermal stress and aircrew thermal strain given ambient temperature and sortie time have been constructed. These provide a description of the temperature relationships within aircraft during flight.