Federal investigators are investigating a fatal plane crash west of Bend that authorities say was intentional.

Deschutes County deputies say 48-year-old Steven Charlton took off from Bend Airport around 1:30 Tuesday afternoon and remained airborne for more than five hours. Sheriff’s Office spokesman Jason Carr says concern grew after Charlton called his wife from the plane, prompting her to contact authorities.

Carr says deputies and negotiators tried to reach Charlton during the flight, while the FBI coordinated with Klamath Falls Air Force Base. Charlton reportedly only wanted to speak with family.

He was the only person aboard. No other injuries or property damage were reported.

The NTSB is asking witnesses to email witness@ntsb.gov.