ELLENSBURG, Wash. (AP) _ Efforts to find an airplane missing for three days with two pilots aboard were widened Sunday, a day after three crew members of a search plane escaped injury in a crash.

''Search flying is an inherently dangerous form of flying,'' said Mac McIver of the state Division of Aeronautics. ''But we're not giving up.''

The three crew members were able to walk away from the crash Saturday of an amphibious plane on a field west of here, McIver said. They were taken to a hospital for observation and released, and the cause of the crash was being investigated, he said.

The search for the two missing pilots, both daughters of Spokane officials, was widened Sunday to new areas of rugged, snowy terrain in central Washington, McIver said.

The missing airplane left Ellensburg late Thursday morning carrying Christine Karstetter, 24, of Seattle, the pilot of the two-seat Cessna 150, and Lisa Brockett, 21, a junior in Central Washington University's flight technology program.

The women, both licensed pilots, had said they were taking a pleasure flight that would last no longer than 1 1/2 hours.

Ms. Karstetter is the daughter of Spokane Valley Fire Battalion Chief Dick Karstetter, and Ms. Brockett is the daughter of Spokane County Prosecutor Donald Brockett. The two men and other family members were in Ellensburg to participate in the search.

About 125 searchers, 45 airplanes and six helicopters helped in the search Saturday. The effort involved Kittitas County sheriff's deputies, the state Division of Aeronautics, the Civil Air Patrol, the Army, the Washington Pilots Association and volunteers.