Nunneley S A, Myhre L G
Aviat Space Environ Med. 1976 Sep;47(9):969-73.
The use of bubble canopies to improve vision in fighter aircraft exposes the cockpit to a high radiant heat load. Incoming sunlight increases the heat stress on crewmembers, both by raising air temperature and by directly heating exposed skin and clothing. An F-15 aircraft at Edwards AFB was modified to permit cockpit ventilation by external ground carts. Eight volunteers from the Test Pilot School were studied during 1-h periods in the closed cockpit, in sun and in shade. Mean cockpit air temperatures were 35.2 degrees C in shade and 51.9 degrees C in sun with PH2O less than 10 torr. The corresponding WBGT's were 22.6 and 36.4 degrees C. Sunlight added significantly to overall heat stress, as indicated by a rising heart rate and evaporative weight loss of 284 g/m2 - h (shade value was 109 g/m2 - hr). Mean skin temperatures were 34.3 degrees C in shade and 35.8 degrees C in sun. Particularly high skin temperatures were observed on the chest, the forehead and the top of the head under the helmet. The legs remained cool due to the flow of conditioned air, and this may explain why rectal temperature showed no meaningful change. Heat stress, which alone poses no physiological hazard, may cause crew performance decrements as well as diminishing acceleration tolerance. Possible means of eliminating or ameliorating these effects are discussed.
在战斗机上使用气泡式座舱罩以改善视野，会使驾驶舱承受高辐射热负荷。入射阳光会增加机组人员的热应激，这既通过升高空气温度，也通过直接加热暴露的皮肤和衣物来实现。爱德华兹空军基地的一架F - 15飞机进行了改装，以便通过外部地面推车实现驾驶舱通风。对来自试飞员学校的八名志愿者在封闭驾驶舱内、阳光下和阴凉处进行了1小时的研究。在阴凉处时，驾驶舱平均空气温度为35.2摄氏度，在阳光下为51.9摄氏度，水汽压小于10托。相应的湿球黑球温度分别为22.6和36.4摄氏度。如心率上升以及蒸发失重量为284克/平方米·小时（阴凉处的值为109克/平方米·小时）所示，阳光显著增加了总体热应激。阴凉处平均皮肤温度为34.3摄氏度，阳光下为35.8摄氏度。在胸部、额头以及头盔下的头顶部位观察到特别高的皮肤温度。由于有调节的空气流动，腿部保持凉爽，这或许可以解释为什么直肠温度没有明显变化。热应激本身虽不构成生理危害，但可能导致机组人员的操作性能下降以及加速度耐力降低。文中讨论了消除或减轻这些影响的可能方法。
