G-Induced Loss of Consciousness and Its Prevention
Abstract
The current capabilities of trained individuals to maintain clear vision during sustained exposures to 9 Gz, an increase in protected G tolerance of about 4 G over World War II fighter pilots, is a result of combined use of a G suit and very effective self-protective straining maneuvers such as the M-1, L-1 and pressure breathing, all of which are variants of the Valsalva maneuver developed in the 1940s. However, more than ten fatal crashes attributed to acceleration-induced loss of consciousness have occurred in recent years. The most plausible causes are: (1) increased capability of jet-powered fighters to sustain, with minimal pilot effort, accelerations in the 7-10 Gz range for periods longer than the symptom-free 3-8 second cerebral ischemic anoxic period which precedes GLOC, (2) an improperly performed Valsalva-type straining maneuver, and (3) development of a hypotensive vasovagal type reaction. A foolproof GLOC warning system such as detection of zero arterial pulsations at ear level to activate an automatic plane control takeover system could avoid most GLOC crashes. However, an omni-directional surveillance fighter plane cockpit for a fully horizontal position, preferable prone, is the only physically and physiologically certain and safest way to eliminate GLOC and to achieve the probable tactical advantages of sustained combat maneuvering in the 9-15 Gz range. Keywords: Acceleration, G stress, Anti-G suit, Anti-G straining maneuver, Acceleration tolerance. (aw)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1988
- Accession Number
- ADA202960
Entities
People
- Earl H. Wood
Organizations
- Mayo Clinic