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- Title
- EFFECTS OF FLIGHT FACTORS ON PILOT PERFORMANCE, WORKLOAD, AND STRESS AT FINAL APPROACH TO LANDING PHASE OF FLIGHT.
- Creator
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Lee, Kyongsun, Lee, Gene, University of Central Florida
- Abstract / Description
-
Since human errors are one of the major causes of flight accidents, the design and operation of the modern aircraft system deals with them seriously. Particularly, the pilot workload on aviation causes human errors. Whenever new procedures are introduced and operated, the aircraft capabilities have been checked in every aspect. However, there has been little study on the impact of the new procedures such as LDLP, SCDA, SATS, and Steep Angle approach on the pilot performance, workload, and...
Show moreSince human errors are one of the major causes of flight accidents, the design and operation of the modern aircraft system deals with them seriously. Particularly, the pilot workload on aviation causes human errors. Whenever new procedures are introduced and operated, the aircraft capabilities have been checked in every aspect. However, there has been little study on the impact of the new procedures such as LDLP, SCDA, SATS, and Steep Angle approach on the pilot performance, workload, and stress. In this study, different methods have been tried to understand the relationship between new procedures and the pilots in terms of performance, workload, and stress. The flight factors (e.g. flight experience, gliding angle, and approach area) were examined by the pilot performance, workload, and stress at the ÂÂ"Final Approach to L/DÂÂ" phase using the single engine Cessna 172R type flight simulator. Five students and five instructor pilots from Embry-Riddle Aeronautical University in Dayton Beach, Florida, participated and they flew under four different simulation tasks of gliding angle and approach area. Their Heart Rate Variability (HRV) and NASA-Task Load Index (TLX) were measured to determine their stress level and subjective workload, respectively. In addition, Landing Performance (LP) data (e.g. landing distance, landing speed) and Above Glide Path Tracking Performance (AGPTP) data were also collected to evaluate pilot performance. As a result, the type of approach area showed a significant effect on pilot performance, workload, and stress determined by ANOVA (HRV, TLX, LP, AGPTP: all are p < .05). Flying over ÂÂ"PopulatedÂÂ" area (e.g. a large city) resulted in lower pilot performance and higher pilot workload and stress than that over ÂÂ"Non-PopulatedÂÂ" area (e.g. a grass field). Similarly, the levels of a gliding angle showed the statistical difference on the performance, workload, and stress (HRV, TLX, and LP: all are p < .05). During the flight with 4.5 degree, the pilots showed lower performance with higher workload and stress. However, the levels of the flight experience did not have any influence on the performance, workload, and stress levels (AGPTP, LP, TLX, HRV: all are p > .05). In conclusion, flying in Populated area and flying with a 4.5 degree gliding angle increases the workload and stress level of the pilots. In addition, when the pilots were flying over Populated area at Final Approach to L/D phase, they showed lower performance on tracking the glide path. Based on the results, stresses and workload can have a significant impact on flight performance. Therefore, in order to reduce the workload and stress that can cause human errors, it is highly recommended to carefully examine the impact of new flight procedures on pilot workload and stress before they are implemented.
Show less - Date Issued
- 2010
- Identifier
- CFE0003489, ucf:48937
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003489
- Title
- Overexpression of human Cu/Zn Superoxide Dismutase in Mice: A Model to Study the Effect of Increased Superoxide Scavenging on the Autonomic Control of the Heart.
- Creator
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Hatcher, Jeffrey, Cheng, Zixi, Bossy-Wetzel, Ella, Fernandez-Valle, Cristina, Belfield, Kevin, University of Central Florida
- Abstract / Description
-
Dysregulation of the autonomic cardiovascular control is a complication of diseases including diabetes, hypertension, sleep apnea, and aging. A common factor in these conditions is an increase in reactive oxygen species (ROS) in neural, cardiac, and endothelial tissues. Cu/Zn superoxide dismutase (SOD1) is an intracellular anti-oxidant enzyme that catalyzes dismutation of the superoxide anion (O2.-) to hydrogen peroxide (H2O2). Expression and function of this enzyme are diminished in...
Show moreDysregulation of the autonomic cardiovascular control is a complication of diseases including diabetes, hypertension, sleep apnea, and aging. A common factor in these conditions is an increase in reactive oxygen species (ROS) in neural, cardiac, and endothelial tissues. Cu/Zn superoxide dismutase (SOD1) is an intracellular anti-oxidant enzyme that catalyzes dismutation of the superoxide anion (O2.-) to hydrogen peroxide (H2O2). Expression and function of this enzyme are diminished in pathologies that impair cardiovascular autonomic control. This study employed mice overexpressing a transgene for human SOD1 (hSOD1) to determine if its overexpression would alter autonomic regulation of BP, HR, and BRS in healthy animals, and if this animal line (C57B6SJL-Tg (SOD1)2 Gur/J) could be used in future studies to determine if hSOD1 overexpression can preserve cardiac autonomic function in disease models. To accomplish this aim, using anesthetized SOD1 and C57 (control) mice, we recorded HR, and aortic depressor nerve (ADN) activity changes in response to pharmacologically-induced BP changes in order to measure baroreflex and baroreceptor sensitivity, respectively. In order to identify any alterations in central, efferent, and cardiac components of the baroreflex arc, we electrically stimulated the left ADN and left cervical vagus and compared the reductions in BP and HR between the C57 and SOD1 mice. Time- and frequency-domain analysis of heart rate variability (HRV) was performed using pulse pressure recordings prior to pharmacologic or surgical procedures. We found that hSOD1 overexpression in the SOD1 mouse line, in comparison to C57 controls did not significantly affect resting HR (C57: 558 (&)#177; 8 vs. SOD1:553 (&)#177; 13 beats-per-minute) or blood pressure (C57: 88.8 (&)#177; 2.9 vs.SOD1: 85.8 (&)#177; 2.1 mmHg). hSOD1 overexpression did not affect the decrease in average mean arterial pressure (MAP) following injection of sodium nitroprusside (SNP) (C57: 38.7 (&)#177; 1.4 vs. SOD1: 39.5 (&)#177; 1.3 mmHg) or increase in average MAP (C57: 135.8 (&)#177; 3.1 vs. SOD1: 136.6 (&)#177; 3.5 mmHg) following injection of phenylephrine (PE). BRS, as measured by the averaged regression lines for ?HR/?MAP for the SNP-induced tachycardic baroreflex (C57: 0.57 (&)#177; 0.06 bpm/mmHg, SOD1: 0.61 (&)#177; 0.08 bpm/mmHg)) and the PE-induced bradycardic baroreflex (C57: -2.9 (&)#177; 0.57 bmp/mmHg, SOD1: -4.3 (&)#177; 0.84 bpm/mmHg) are not significantly different between C57 and SOD1. Baroreceptor activation showed a significant increase in gain (C57: 5.4 (&)#177; 0.3 vs. SOD1: 7.4 (&)#177; 0.5 %/mmHg, P (<) 0.01) in the SOD1 transgenic mice. Heart rate depression in response to electrical stimulation of the left ADN and cervical vagus was comparable between C57 and SOD1, though MAP reduction in response to ADN stimulation is slightly, but significantly increased at 50 Hz in SOD1 animals. Time- domain analysis of HRV did not reveal any significant difference in beat-to-beat variability between SOD1 and C57 (SDNN: C57: 2.78 (&)#177; 0.20, SOD1: 2.89 (&)#177; 0.27), although frequency-domain analysis uncovered a significant reduction in the low-frequency power component of the HRV power spectral distribution (C57: 1.19 (&)#177; 0.11, SOD1: 0.35 (&)#177; 0.06, P (<) 0.001). This study shows that although hSOD1 overexpression does not affect overall baroreflex function, it does potentiate baroreceptor sensitivity and brain stem control of arterial pressure, and reduces low-frequency beat-to-beat variations in HR, without affecting total HRV.
Show less - Date Issued
- 2015
- Identifier
- CFE0005803, ucf:50025
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005803
