Man Rating the B-1B Molecular Sieve Oxygen Generation System

摘要

This report sets forth the findings of a test and evaluation (man rating) of the molecular sieve oxygen generation system developed for the 1B Long Range Combat Aircraft. A series of unmanned and manned tests, covering the range of aircraft operating conditions, were conducted on a duplicate of the aircraft breathing system which was assembled in an environmental chamber. The control variables were cabin and aircraft ambient pressure, inlet air temperature and pressure, cabin temperature, and demand flow; and the dependent variables were oxygen concentration, pressure swings in the mask, and time required for backup oxygen to reach the crew after rapid decompression (RD). Oxygen output met or exceeded specification requirements for all but two test points. Under nominal aircraft operating conditions and the maximum average demand flow of 160 liters per minute (1pm), oxygen concentration fell slightly below specification requirements at 25,000 and 28,000 ft cabin altitude. These discrepancies are not considered significant (i.e., will not compromise crew safety), because the probability is very slight that a demand flow rate as high as 160 1pm will ever occur (tests showed that 6 persons taking moderately heavy, rapid breaths generated 135 1pm average demand at ground level). Furthermore, the oxygen partial pressure, in the worst case, was equivalent to breathing air at only 4,000 ft pressure altitude.