Nuclear Studies of G Induced Loss of Consciousness (G-LOC)

Abstract

In modern high performance aircraft, gravitational stress, which can sometimes lead to G induced loss of consciousness (Gravitational Loc), is a real threat to pilot safety. G-LOC is a state of altered perception wherein one's awareness of reality is absent as a result of sudden, critical reduction of cerebral blood circulation caused by increased G force (5). Since 1982 there has been a total of 18 class A mishaps involving G-LOC, including 9 which occurred in the highly maneuverable F-16. At Holloman AFB, all candidate F-4/F-15/F-16 pilots must achieve straining, protected gravitational tolerances up to 9 Gz. In attempting to pass this criterion in the past, at least 10% of all trainees lost consciousness (6); today, because of better training techniques, only about 6% of trainees experience G-LOC (8). If the trainee fails at achieving the 9 Gz exposure (or loses consciousness), he is allowed to repeat the exposure after a brief rest. During G-LOC, a number of bodily functions may be monitored to evaluate the physiological effects of loss of consciousness. Electrocardiogram (EKG) profiles, during unconsciousness in general, are not altered beyond normal excessive G stress response (16). In the electroencephalogram (EEG) record, however, a distinct change in frequency from high (alpha) to low (delta) occurs during unconsciousness (9).

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1990
Accession Number
ADA243506

Entities

People

  • A. Karl
  • J. Riddell Iv
  • James Cooper
  • Stephen Bolia
  • William B. Albery

Organizations

  • Armstrong Laboratory

Tags

Communities of Interest

  • Biomedical

DTIC Thesaurus Topics

  • Air Force
  • Blood Flow
  • Blood Volume
  • Brain
  • Cardiovascular Physiological Phenomena
  • Experimental Design
  • Health Services
  • Laboratory Animals
  • Magnetic Resonance
  • Magnetic Resonance Imaging
  • Medical Personnel
  • Metabolism
  • Neurons
  • Nuclear Magnetic Resonance
  • Positron Emissions
  • Positrons
  • Resonance

Readers

  • Aviation Science / Aeronautics.
  • Cardiovascular Physiology
  • Economics