Advanced In-Flight Rebreather

Flight crews require supplemental oxygen for emergency high-cabin-altitude operations. Some personnel require a walk-around oxygen supply to move freely throughout the cabin until the altitude is reduced to a safe level. Current low-pressure bottles cannot supply oxygen for an adequate duration in an acceptable cylinder size, and multiple cylinder fills are usually required to meet common mission requirements, adversely impacting logistical and safety issues. Rebreather technology offers the potential to meet the need in a compact system with minimal oxygen storage requirements. Although rebreather technology has been applied successfully to diving and some land-based applications for many years, a high-altitude, walk-around system for aviation use presents new challenges. On the proposed Phase II effort, we will apply innovative technology developed during Phase I to produce an optimized aviation rebreather. We will develop a fully functional integrated demonstration unit and test it extensively in the laboratory with a metabolic breathing simulator. These tests will cover a range of breathing rate, operating temperature, and ambient pressure. We will conduct confirmatory testing with human test subjects in a hypobaric chamber. We will also develop fieldable system concepts and produce evaluation articles that will allow us to evaluate human factors and manufacturing issues.