Effects of different helmet-mounted devices on pilot’s neck injury under simulated ejection

The helmet plays an important role in protection of pilot’s head and enhances the pilot’s capabilities and performance significantly with the use of mounted devices such as the Night Vision Goggle (NVG). However, the use of helmet-mounted devices might increase the risk of injury due to the increased helmet weight and change in the centre of gravity of head. In this study, four helmets with different combinations of mounted devices were modelled in a validated human head–neck multi-body model to analyse their effects on the pilot’s neck injury during simulated ejection. The probability of neck injury was evaluated and predicted using the Nij neck injury criteria and human injury risk curves, considering the tolerance of injury for upper and lower cervical segment. It was demonstrated that the helmet-mounted devices would increase the compression force and bending moment on cervical spine, especially for the lower cervical segments with higher Nij. In the cases with Night Vision Goggle, Nij of the lower cervical segment reached 0.54, which exceeded the requirement in aviation filed. For the cases with Visor, excessive extension occurred, resulting in a high Nij. The simulation results of this study could provide a reference for helmet and mounted devices design and offer a proposal for the protection of pilots during ejection.