Olson R M, Cooke J P
Aviat Space Environ Med. 1978 Feb;49(2):371-4.
The need for aircrew members to use long breathing hoses between regulator and mask arises in the design of new transport aircraft and in several cargo operations requiring an open rear door. In this study, induced work of breathing through long hoses, the resulting changes in oxygen consumption, and comfort were studied in relation to altitude, hose length, and exercise level. Conclusions were that, above 18,000 ft (5.5 km), a 30-ft (9.1-m) hose is acceptable for all reasonable work levels; for altitudes between 13,000 and 18,000 ft (4.0 and 5.5 km), the hose length should preferably be 18 ft (5.5m), and at altitudes below 13,000 ft (4.0 km), hose length should be limited to 12 ft (3.6). Moreover, at ground level, the hose length should be limited to 6 ft (1.8 m) for all but sedentary activity. Should the potential for rapid decompression exist, at any altitude, volume considerations limit hose length to 18 ft (5.5 m) since larger hoses possess excessive regulator-to-mask dead space.
在新型运输机的设计以及一些需要打开后门的货运操作中，机组人员需要在调节器和面罩之间使用长呼吸软管。在本研究中，针对海拔高度、软管长度和运动水平，研究了通过长软管呼吸所产生的诱导呼吸功、由此导致的氧气消耗变化以及舒适度。研究得出的结论是，在18,000英尺（5.5千米）以上，对于所有合理的工作强度，30英尺（9.1米）的软管是可以接受的；对于海拔在13,000至18,000英尺（4.0至5.5千米）之间，软管长度最好为18英尺（5.5米），而在海拔低于13,000英尺（4.0千米）时，软管长度应限制为12英尺（3.6米）。此外，在地面水平，除久坐活动外，软管长度应限制为6英尺（1.8米）。如果存在快速减压的可能性，在任何海拔高度，出于容积考虑，软管长度应限制为18英尺（5.5米），因为较大的软管会产生过多的调节器到面罩的死腔。
