A small plane crashed into a Weld County field last week, killing the 81-year-old Nebraska pilot and kickstarting a federal investigation. Alex Watson, a Nebraska man known as Ben by friends and family, earned his final set of wings on Friday. According to the National Transportation Safety Board, the Beech 35-B33 — a private, single-engine plane manned by Watson — took off from Chadron, Nebraska, between 7:30 a.m. and 8:30 a.m. on Friday, headed for Hudson. The plane, registered to Watson and his wife, crashed in a field near Nunn in Weld County around 2 p.m. Friday, just 50 miles north of Watson’s final destination, according to a preliminary crash report from the Federal Aviation Administration. The FAA labeled the crash as an accident, but federal investigators still aren’t sure what caused it and said the investigation could take up to two years to complete. Watson served in the U.S. Navy for six years, including as an aircraft commander during the Vietnam War, before starting a more than 30-year career as a pilot with Continental Airlines, according to his obituary. He retired in 2003 but “continued his love of general aviation, spending every summer flying to Oshkosh and Sun-n-Fun,” his family wrote in the obituary. FAA officials said Watson was killed during the crash and was the only person on board. Related Articles Crashes and Disasters | Motorcyclist dies after crash in south Denver Crashes and Disasters | Hunter found dead after expedition in Great Sand Dunes National Park Crashes and Disasters | Colorado School of Mines professor charged with homicide, assault in crash that killed Golden police officer Crashes and Disasters | Colorado State Patrol trooper struck, injured by suspected drunken driver in El Paso County Crashes and Disasters | Memorial service announced for Golden police officer killed in suspected DUI crash An NTSB investigator traveled to the nearly 5-acre crash site, about the size of 3 1/2 football fields, to document the airplane wreckage on Friday. The plane was completely destroyed. Investigators are asking witnesses to the accident or anyone with surveillance video relevant to the investigation to contact the NTSB at [email protected]. Sign up to get crime news sent straight to your inbox each day.