Prevention of Loss of Consciousness with Positive Pressure Breathing and Supinating Seat
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX CREW TECHNOLOGY DIV
Pagination or Media Count:
Maintaining vision and consciousness at high sustained Gz requires a total body effort for most people, and is very fatiguing. Currently, the only pieces of operational G-protective equipment are the anti-G suit and anti-G valve which provide relaxed G-tolerance protection to about 5.5 G. Protection above 5.5 G requires the anti-G straining maneuver AGSM. Assisted positive pressure breathing APPB has been shown to augment sustained Gz tolerance and reduce the amount of straining necessary to maintain a specific Gz level. Moreover the supinating seat has been shown to double relaxed G tolerance at a back angle of 75 deg from the vertical when compared to relaxed tolerance at a 13 deg or 30 position. Problems of cockpit engineering, escape, head-rest angle, restricted rear visibility, and pilot acceptance of a high angle supinated seat may preclude the use of a seat with sufficient back angle to provide no strain G protection. Thus, the addition of APPB to a limited protective seat may provide adequate and acceptable G tolerance.
- Stress Physiology