HEAT-STRESS IN THE A-10 COCKPIT - FLIGHTS OVER DESERT

  • 1 January 1981
    • journal article
    • research article
    • Vol. 52  (9) , 513-516
Abstract
Heat stress is a significant problem during low-level flight in hot climates, especially in aircraft that impose high task loads and repetitive maneuvering forces. The A-10 close-support aircraft presents such a combined-stress environment. Data were summarized from 15 low-level flights over desert. Ground dry-bulb temperature (Tdb,g) was 26-42.degree. C. Cockpit temperature (Tdb,c) was commonly over 40.degree. C on the ground and tended to drop progressively from taxi-out through flight to the range and return; for any given phase it was a linear function of Tdb,g. Small (50-mm) black globe temperature (Tbg,s) exceeded Tdb,c by 2-5.degree. C on the ground and by 4-8.degree. C in flight. The pilot''s mean skin temperature was a linear function of Tdb,c in each phase. Auditory canal temperature (Tac) rose from a control value of 37.0.degree. to a mean of 37.4.degree. C in flight, with one pilot reaching 37.8.degree. C. Sweat rate was a linear function of Tdb,g, with weight loss up to 2.3%. These data are compared to earlier studies of the F-4 and F-111 aircraft. Although the performance of the A-10''s cooling system resembles that in other aircraft and is somewhat better than the F-4 on the ground, the effects of cockpit heat are exacerbated by its close-support role. Pilots noted lowered g-tolerance and increased general fatigue on the hotter flights. The foot- and leg-area temperatures exceeded those at the head; planned changes in air distribution should partly alleviate the situation.