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Physiological effect of high, sustained +Gz forces on man
1Biodynamics Branch, USAF School of Aerospace Medicine, Brooks Air Force Base, Texas 78235, USA.
Life Sciences and Space Research
|January 1, 1979
Summary
Human volunteers tolerated high sustained G-forces up to +9 Gz using anti-G suits and straining maneuvers. However, physiological monitoring did not reveal specific tolerance limits, with fatigue and blackout being common reasons for stopping runs.
Area of Science:
- Aerospace Medicine
- Human Physiology
- G-force Tolerance
Background:
- High sustained G-forces pose significant risks to aviators.
- Understanding physiological responses is crucial for safety.
Purpose of the Study:
- Evaluate physiological responses to high sustained +Gz forces.
- Identify objective criteria for medical tolerance endpoints.
Main Methods:
- Two studies using a 20-ft radius Human Centrifuge.
- Volunteer subjects wore anti-G suits and performed straining maneuvers.
- Exposures ranged from +6.5 Gz to +9.0 Gz for 45-60 seconds.
Main Results:
- Nine of 14 subjects maintained vision at +9 Gz for 45 seconds.
- Common reasons for stopping runs above +7.5 Gz included fatigue and blackout.
- Recorded physiological parameters did not provide specific tolerance limit criteria.
Conclusions:
- Some individuals can tolerate high sustained G-forces with protective gear and maneuvers.
- Current physiological monitoring methods are insufficient to define precise G-force tolerance limits.
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