Killed were Bill Keating, 52, the pilot of the aircraft that was struck, and two grandsons, ages 1 and 6, McCall police and fire officials said in a statement.
Another grandson, 2, was flown to the University of Utah Burn Center in critical condition, the statement said.
The pilot of the landing aircraft, Justin Mooney, 30, and passenger Mark Fuller, 27, pulled the 2-year-old from the burning plane, the statement said. They were treated and released from McCall Memorial Hospital, a nursing supervisor said Saturday.
Mooney and Fuller had taken off from Felts Field at Spokane, Wash., Gregor said.
The McCall airport, which has no air traffic control tower, remained closed Saturday while federal authorities investigated.