仪表飞行时直升机飞行员脑力负荷的主观评价

Mental workload assessment of helicopter pilots in instrument flight with subjective rating measurements

目的脑力工作超负荷可影响人的工作绩效并威胁飞行安全;大部分飞行事故发生在脑力工作负荷强度大的起飞、仪表或手动进近和着陆阶段,而且多是由人为差错引起。因此,为提高飞行作业绩效,维护飞行安全,测量和评定飞行员空中脑力工作负荷具有越来越重要的现实意义。本研究的目的是观察直升机飞行员仪表飞行时的脑力负荷变化。方法采用修改的美国国家航空航天局任务负荷指数(NASA-TLX)评价量表,对15名直升机飞行员仪表飞行时不同阶段的脑力负荷进行了主观评价;对总脑力负荷评价值和飞行小时数进行了线性回归分析。结果在起飞爬升阶段、巡航平飞阶段、下滑着陆阶段飞行员的总脑力负荷值分别为34.46±17.25、32.11±13.11和53.95±17.76。下滑着陆阶段飞行员的总脑力负荷值显著高于起飞爬升阶段和巡航平飞阶段的总脑力负荷值(F=25.767,P<0.01)。3个阶段的总脑力负荷的评价值均与飞行小时数呈显著负相关。在起飞爬升阶段,总脑力负荷的评价值与飞行小时数的线性回归方程为:总脑力负荷评价值=42.20-0.01203×飞行小时数(r=-0.810,P<0.01);在巡航平飞阶段,线性回归方程为:总脑力负荷评价值=38.51-0.00604×飞行小时数(r=-0.535,P<0.05)。在下滑着陆阶段,线性回归方程为:总脑力负荷评价值=62.57-0.00814×飞行小时数(r=-0.532,P<0.05)。结论军用直升机飞行员仪表飞行时总脑力负荷的评价值与飞行小时数呈显著负相关,在下滑着陆阶段脑力负荷最大。

Objective Mental overload directly affects human performance and threats to flight safety. Most of the aviation accidents are due, at least in part, to human error, especially in the phases of take-off, instrument or manual approach and landing, when mental overload occurs. Assessment of pilot mental workload is, therefore, an important aviation management issue, as enhancing flight performance and ensuring flying safety are considered. The purpose of this study was to evaluate in-flight mental workload of helicopter pilots. Methods Fifteen male military helicopter pilots from a corps participated in this study. Subjective mental workload assessment of three flight phases using modified multidimensional National Aeronautics and Space Administration-task load index （NASA-TLX） questionnaire on military helicopter pilots were rated after instrument flight. Linear regression analysis was performed between total flying hours and overall TLX subjective workload rating scores in different flight phases. Results The overall TLX subjective workload rating scores in the take-off, cruise, and landing phases were 34.46±17. 25, 32.11± 13. 11, 53. 95±17. 76, respectively. The landing TLX scores were significant higher in comparison with take-off and cruise phases （F= 25. 767, P〈 0.01）. Significant negative correlations between flight hours and subjective workload rating scores were noted for the three flight phases. During the take-off phase coefficient of correlation between flight hours and subjective workload rating scores was -0. 810 （P〈 0.01） and the linear regression equation of the two variables was： TLX scores ： 42. 20- 0. 012 03 × flight hours. During the cruise phase, coefficient of correlation between flight hours and subjective workload rating scores was -0. 535 （P〈0. 05） and the linear regression equation of the two variables was： TLX scores=38.51- 0. 006 04 × flight hours. During landing phase, coefficient of correlation between flight hours and subjective workload rating scores was -0. 532 （P〈0.05） and the linear regression equation of the two variables was： TLX scores = 62. 57-0. 008 14 × flight hours. Conclusion Analysis of the TLX scores for our participants reveals that the subjective mental workload is higher during landing phase as compared with other phases. The results also indicate that, subjective in-flight mental workload is alleviative with the accumulation of flight experience.