PREVENTION OF DECOMPRESSION-SICKNESS IN CURRENT AND FUTURE FIGHTER AIRCRAFT

United States Air Force oxygen regulators set to ''NORMAL OXYGEN'' del iver up to 60% nitrogen to the pilot at cockpit altitudes of 15,000 to 20,000 ft (4573-6096 m). Research chamber exposure to these altitudes while breathing 50% nitrogen has resulted in high grades of venous ga s emboli. Expansion of existing gas emboli following an unplanned deco mpression to ambient aircraft altitude (e.g., loss of canopy) could re sult in rapid development of decompression sickness (DCS) symptoms. To reduce this potential problem, regulators in current fighters should be set to ''100% OXYGEN'' until descent from cruise to increase denitr ogenation. The United States' Advanced Tactical Fighter and the Europe an Fighter Aircraft may be designed to cruise above 50,000 ft (15,240 m), where cockpit altitudes exceed 20,000 ft with a 5-psi differential (psid) cockpit pressurization schedule. Increasing cockpit differenti al pressure to 7 psid while breathing 1 00% oxygen would greatly reduc e the chance of significant emboli formation and the potential for DCS , but would slightly elevate the risks associated with pulmonary over- pressure during rapid decompression.