Development and evaluation of hybrid seat cushions for helicopter aircrew vibration mitigation

This article investigates the use of novel energy-absorbing materials to reduce vibration transmitted through helicopter pilot seat cushions. A type of engineered material known as the hybrid air cushioning system was integrated into the design of helicopter seat cushions in addition to conventional foam materials. The prototype seat cushions were preliminarily evaluated as the bottom seat cushion on a Bell-412 nonarmored pilot seat through mechanical shaker tests. The promising cushion designs were further evaluated on a Bell-412 helicopter through extensive flight tests. The pilot whole-body vibration levels were assessed in accordance with ISO 2631-1:1997 standard. The flight test results demonstrated that the prototype cushions were able to reduce significantly the pilot whole-body vibration. Therefore, the integration of hybrid air cushioning system with Bell-412 seat cushion can serve as a low-cost solution to mitigate the vibration levels transmitted to helicopter pilots.