former staff sgt. charlie linville , 29 , from boise , idaho , was an explosives expert serving in afghanistan in 2011 when he was seriously wounded .
two years later , he had his right leg amputated below the knee .
he retired from service and has been climbing since with the heroes project , a nonprofit organization that helps wounded veterans .
his quest to climb everest last year was thwarted following the deaths of 16 sherpa guides in april when an avalanche swept down .