PHOENIX -- Two people remained hospitalized Thursday with minor injuries after a helicopter belonging to an air ambulance company crashed on Arizona's San Carlos Indian reservation during a training flight, authorities said.

There were no patients on the flight.

The pilot of the Eurocopter AS 350 lost control while trying to land at Cutter airport about 7:30 p.m. Wednesday, Federal Aviation Administration spokesman Ian Gregor said.

The helicopter belonged to EMS transportation provider Native Air, a subsidiary of Texas-based Omniflight Helicopters.

Omniflight said the chopper was not an air ambulance and was used solely for pilot training. It had departed Wednesday from Williams Gateway Airport.

The company said the two pilots remained in a Phoenix hospital.

The FAA and the National Transportation Safety Board will investigate the crash, which caused substantial damage to the aircraft.

The San Carlos Apache Reservation is located along U.S. 70 between Globe and Safford, in Gila County, about 60 miles east of Phoenix.