Document Detail


Human tolerance to Gz acceleration loads generated in high-performance helicopters.
MedLine Citation:
PMID:  11506230     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: As the Gz capabilities of tactical helicopters increase, the risk to unprotected helicopter aircrew resulting from the physiologic response to transitions from -1 Gz (push) to +4.5 Gz (pull) loads needs to be addressed. METHODS: There were 9 volunteers who participated in a study conducted at the Veridian Operations Centrifuge Facility in Warminster, PA. A 1-h mission scenario consisting of nine helicopter maneuvers, based on inflight G measurements (push-pull mission, PPM), simulated both current (CM: -0.2 to +3.5 Gz) and projected future platform capabilities (FM: -1 Gz to +4.5 Gz). Additional scenarios were run in which push transitions were limited to +1 Gz (GM). Measurements included blood pressure (BP), heart rate (HR), loss of vision, and subjective fatigue. RESULTS: Visual decrements were minimal during CM while muscular tensing was required to avoid blackout during FM. Light loss typically occurred during the transition from -Gz to +Gz. Within the scope of these tests, subjects tolerated the range of Gz stresses associated with current U.S. Navy rotary wing platforms. When subjected to FM G-loads (typical of current U.S. Army high-performance platforms), cardiovascular stress significantly increased, Gz tolerance dropped as much as 1.2 G, and HR increased as much as 67 bpm. Cardiovascular changes were significantly greater during FM PPM relative to GM. Four subjects reported Almost-Loss of Consciousness (A-LOC) symptoms during FM. CONCLUSIONS: While G-stress experienced by aircrew generated by current helicopters does not appear to present a high risk, G-awareness training is recommended to reduce risks to aircrew exposed to G-loads generated by more aggressive helicopters. Future studies are required to determine the impact of longer mission times and dehydration.
Authors:
B S Shender
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  72     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2001 Aug 
Date Detail:
Created Date:  2001-08-16     Completed Date:  2001-12-20     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  693-703     Citation Subset:  IM; S    
Affiliation:
Naval Air Warfare Center Aircraft Division, Patuxent River, MD 20670-1906, USA. ShenderBS@navair.navy.mil
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acceleration / adverse effects*
Adaptation, Physiological / physiology*
Adult
Aircraft*
Analysis of Variance
Blood Pressure / physiology
Electrocardiography
Female
Humans
Hypergravity / adverse effects*
Male
Unconsciousness / physiopathology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Gangliosides from human granulocytes: a nano-ESI QTOF mass spectrometry fucosylation study of low ab...
Next Document:  A mechanical model of cerebral circulation during sustained acceleration.