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E A Alvarez

Publications and source records attributed to E A Alvarez.

4 recordsLinked to original sources
PubMed1998

An evaluation of the British Army spatial disorientation sortie in U.S. Army aviation.

BACKGROUND: Following didactic instruction, most aircrew are able to experience some of the disorienting illusions and limitations of the orientation senses in a variety of ground-based devices. In order to reinforce instruction in spatial disorientation (SD) within the environment in which they operate, British Army Air Corps helicopter pilots also receive an airborne demonstration of the limitations of their orientation senses prior to rotary-wing instrument flight training. The objective of this assessment was to determine whether the SD demonstration sortie would be an effective adjunct in training aircrew in SD in the U.S. Army. METHODS: There were 45 aviators and training personnel who experienced the sortie and gave their opinion in questionnaires. RESULTS: The following conclusions were made: the maneuvers performed in the SD demonstration sortie, and the sortie overall, were extremely effective at demonstrating the limitations of the orientation senses; the SD sortie attracted a significantly higher rating in its effectiveness to train aviators in SD than all the currently available methods; the introduction of the sortie into the initial flight training syllabus would be a distinct enhancement to the SD training of aviators and associated personnel; and the introduction of the sortie into refresher training in field units would also be an advantage. CONCLUSION: Other services are encouraged to consider this enhancement to the SD training of aviators.

Aerospace Medicine↗
PubMed1998

Flight simulator evaluation of a novel flight instrument display to minimize the risks of spatial disorientation.

BACKGROUND: Spatial disorientation (SD) in flight remains a major source of attrition. Many SD accidents would occur regardless of the instrument display in use, since the aircrew are simply not looking at the instruments. However, there are a number of accidents which might be amenable to improved instrument displays. In an attempt to improve maintenance and reattainment of correct orientation with a reduced cognitive workload, a novel instrument display has been developed. This paper describes an assessment of the display in a UH-60 helicopter flight simulator. HYPOTHESIS: This study tested the hypothesis that during instrument flight and recovery from unusual attitudes, the novel display permits a more accurate maintenance and reestablishment of flight parameters than the standard flight instruments. METHODS: There were 16 male aviators who flew a simulated instrument flight profile and recovery from unusual attitudes using both the standard flight instruments and the novel display. The two display formats were tested both with and without a secondary task. RESULTS: When compared with the standard instruments, both control of flight parameters and recovery from unusual attitudes were significantly improved when using the novel display. Analysis of the secondary task scores showed that cognitive workload was reduced when using the novel display compared with the standard instruments. CONCLUSIONS: Results from all aspects of the assessment indicated benefits of the new display. Future testing should be carried out during real flight, and the display should be further developed to be used in a head-up or helmet-mounted device.

Adult↗
PubMed1998

The optokinetic cervico reflex during simulated helicopter flight.

INTRODUCTION: The optokinetic cervico reflex (OKCR) is a recently hypothesized, visually driven reflex that serves to stabilize the image of the external horizon on the retina during roll maneuvers in high-performance aircraft. Although reported anecdotally, head tilt during helicopter flight has not been studied formally. Such research is required to determine the full impact and significance that it may have on the flying performance of a rotary-wing aviator. OBJECTIVE: The aim of this study was to investigate the relationship between horizon position and the perception of orientation and, thus, to generate vital information to assess whether OKCR plays an important role in spatial disorientation. HYPOTHESIS: Pilots of rotary-wing aircraft will exhibit the OKCR. METHODS: A UH-60 flight simulator study, with 20 volunteer pilots participating, was performed to examine the effects of this reflex during day flight and during flight with night vision goggles (NVGs). RESULTS: The results confirm that the OKCR occurs during simulated helicopter flight, both with and without NVGs. As with previous studies, head roll increased during flight under visual meteorological conditions in relation to an increasing aircraft roll angle up to a maximum sustainable level and then remained constant. Head roll did not occur during flight under instrument meteorological conditions. CONCLUSION: The presence of the OKCR will impact rotary-wing operations. Various aspects are discussed, and recommendations are made for future research.

Adult↗