Development and justification of the means and ways of helicopter passenger neck injury prevention during an emergency landing
Aviation Company Progress named after N.I. Sazykin, 5, sq. Lenin, Arseniev, Primorsky Region, 692330, Russia
Preventing injuries of passengers and crew members of the modern helicopters is a key factor for providing competitive success on the transport vehicles market of today. However, the existing equipment that ensures injury prevention for helicopter passengers under emergency conditions is represented by complex engineering systems, which are based on the obsolete energy absorbing chair design. Such chairs are built according to a concept with a uniaxial shock absorption system and safety belts, which cannot ensure complete passenger safety during an emergency landing.
Neck and vertebral column injuries are the most dangerous and probable passenger traumas, which can occur during an emergency landing due to limited physiological capabilities of the human body under the overload exposure. Such injuries are caused by the «head nod» (rapid downward movement of the head) effect. «Head nod» is caused by a moment due to the misaligned positions of centers of mass of human head and body. A new concept of injury prevention system has been developed based on leading edge technologies to eliminate this moment and prevent nodding. This concept focuses on a passenger chair design, which incorporates a neck protection system, programmable deformable elements and shock absorption system. Neck protection is based on the use of the D3O innovative material. D3O is a newest-generation energy-absorbent material, which is capable of protecting passenger’s neck against injury without causing any discomfort. D3O is also used in chair upholstering, which contributes to further improving passenger comfort and additionally relieving his vertebral column regions. The shock absorption system employs programmable deformable elements. These include shear pins and chair frame slide with controlled destruction, which occurs when the loads exceed critical level. The guide rails of the shock absorption system are formed into arch shapes. Such shapes ensure partial change of the direction of the overload force vector from vertical plane towards horizontal and thus provide better compensation of the moment. The method of safety belt attachment has also been modified to improve passenger fixation.
Introduction of these elements combined with the use of shock absorbers with adjustable rigidity will allow the designers to both prevent neck injuries and reduce loads on the upper, middle and lower regions of the vertebral column.
Keywords:injury prevention, programmable deformation, neck protection system, minimization of the acting force, energy-absorbent material, D3O
- Uilkinson U.L. Nen’jutonovskiez hidkosti (Non-Newtonian fluids), Moscow, Mir, 1964, 209 p.
- DZO, 2013, available at: www.d3o.com