20040522010089A

(-23) Aircraft became missing when it did not arrive in boise, Idaho at a predetermined time. The pilot was scheduled to undergo testing and the aircraft was to be inspected for the purpose of going on a contract for fire fighting operations with the U.S. Forest service. The flight originated in dillon, Montana and the weather in the dillon area was very wintery conditions. The pilot told his boss he would follow an interstate to Idaho falls, Idaho and then go on to boise. The search for the missing aircraft centered around radar plots which were recorded of the path of flight after the aircraft departed from dillon. The pilot did not follow the interstate but was tracked across a mountainous route with the path ending at mt. Borah in central Idaho. A rancher on horseback was riding in the valley below the site of the accident. He reported heavy snow storms during the time this accident was thought to have occurred. He saw the aircraft pass over him on a course that would take him to where the aircraft was eventually found. The wreckage was found at 10200 feet on the side of the mountain in deep snow. The site will be inaccessible until late summer. The date of the pilot's last check ride could not be found.