Research on the impact of increasing the ejection seat backrest angle on pilot seating comfort

Hao Mengting; Chen Yuanyuan; Ma Xiaoli; Hu Bo; Bai Yu

doi:10.16289/j.cnki.1002-0837.2025.03005

Abstract：Objective To investigate the effects of increasing the ejection seat backrest angle on the body pressure distribution of pilots of different body types,and to provide a basis for the design of ejection seats,flight training,and the development of strategies to alleviate muscle fatigue.Methods Male fighter pilots were divided into normal and overweight groups according to their body mass index(BMI),and a total of 40 pilots were tested for the distribution of sitting pressure under the two seat inclination angles of 20°and 33°by using the body pressure distribution measurement system.The effects of different seat inclination angles on sitting comfort were also analyzed.Results The pressure distributions of pilots with different body types were significantly different at different seat inclination angles.Compared with the 20°seat,the 33°seat condition had a larger cushion contact area[F(1,78)=40.281,P<0.001],a smaller average pressure and average pressure gradient[F(1,78)=32.030,P<0.001;F(1,78)=12.594,P<0.001],and significantly reduced average,maximum pressure,and maximal pressure gradients for the backrest[F(1,78)=10.516,P=0.002;F(1,78)=26.803,P<0.001;F(1,78)=4.918,P=0.029,respectively].In addition,overweight individuals with BMI had a notable increase in the cushion contact area[F(1,78)=21.038,P<0.001]and the backrest contact area[F(1,78)=8.301,P=0.005].No significant interaction was observed for angle and BMI.Conclusion An increased seat inclination angle results in a more uniform distribution of pressure across the human body,thereby increasing comfort.Moreover,the disparities in pressure and backrest distribution across disparate body types at varying seat angles provide a vital foundation for the optimized design of seating.