MENDON, N.Y.—The three National Guard members killed when a helicopter crashed in an upstate New York field this week were experienced pilots with past deployments to Afghanistan, officials said Friday. Killed in the crash were Chief Warrant Officer 5 Steven Skoda, 54, of Rochester, Chief Warrant Officer 4 Christian Koch, 39, of Honeoye Falls, and Chief Warrant Officer 2 Daniel Prial, 30 of Rochester, according to the National Guard. The UH-60 Black Hawk medical evacuation helicopter crashed in a farmer’s field near Mendon, south of Rochester, around 6:30 p.m. Wednesday. There were no survivors. Witnesses who called 911 reported hearing an engine sputtering and said the helicopter was flying very low. An Army Safety Investigation team arrived at the site Thursday from Fort Rucker in Alabama. Skoda served in the Army from 1985 to 1987 and joined the National Guard 1987. He was a veteran of the Afghanistan War and …