He failed the technical training due to "deficiency in the instrument phase", losing his opportunity to become a warrant officer pilot. The ongoing withdrawal of U.S. forces from Vietnam and consequent surplus of qualified helicopter pilots may have also been a factor in Preston not being accepted as a pilot. Preston was still bound by his four-year obligation to serve with the U.S. Army, and he was sent to Fort Meade, Maryland, as a helicopter mechanic in January 1974.[1] At the time of the incident, he was 20 years old, with the rank of private first class; he was described by his commanding officer as a "regular, quiet individual" with above-average intelligence.[2]