Evaluation of various padding materials for crash protection.

PDFTech ReportAM 66-40DOT/FAA/AM-66/40Aircraft accidentsTransportation safetyCrash injuriesSet forward forceVehicle paddingDummiesHeadFaceSled testsVelocityImpact testsExperimentsCompression testsUnited StatesCivil Aerospace Medical InstituteSwearingen, John J.United States. Office of Aviation MedicineNTL-AVIATION-AVIATIONNTL-AVIATION-Aviation Safety/AirworthinessNTL-SAFETY AND SECURITY-AccidentsNTL-SAFETY AND SECURITY-Aviation Safety/AirworthinessNTL-SAFETY AND SECURITY-Vehicle DesignUS Transportation CollectionThirty-seven different materials and combinations of materials were impacted with an instrumented dummy head at 15 ft/sec and at 30 ft/sec. Peak g forces, rise times, and deceleration durations were determined for both impact velocities on each test specimen and compared to base line impacts on the rigid base structure to determine the degree of energy attenuation of each type of padding.As might be expected there was a progressive decline of peak g force with increased thickness of padding materials. None of the 1/4 inch, 1/2 inch, or 3/4 inch materials tested at 30 ft/sec and only one of the 1 inch materials had sufficient energy attenuation to bring the peak g force even close to survivable limits while all materials tested of 2 inch thickness or over reduced the impact force of 30 ft/sec impacts to 300g or less. At 15 ft/sec impact velocities all materials tested of 1 inch thickness and over and at 30 ft/sec materials of 2 inch thickness and over would probably offer some protection against fatal head injury.However, since in commercial crashes head impact velocities may be as high as 50 ft/sec and it is important that the passengers remain conscious to escape ensuing fire and smoke, padding per se (even six inches thick) is insufficient. A combination of deforming metal to dissipate energy and firm padding to distribute pressure forces over the contour of the facial bones may be used successfully in preventing head injury and/or unconsciousness