On October 12, 2004, about 1230 Alaska daylight time, a skid-equipped Eurocopter AS-350B2 helicopter, N166EH, operated by Era Aviation, Inc., as an on-demand Title 14, CFR Part 135 flight, sustained substantial damage when the main rotor blades collided with a tree while landing at a remote site, about 15 miles southeast of Ketchikan, Alaska. The airline transport certificated pilot and the one passenger were not injured. The local flight operated in visual meteorological conditions, and a company VFR flight plan was in effect. The flight departed Ketchikan about 0730. The operator reported that the pilot had been ferrying passengers between remote sites in mountainous and thickly forested areas throughout the morning. On the last landing, the pilot reported he noticed damage to the main rotor blades. He said he was uncertain of when the damage occurred, but the operator noted it likely happened on his last landing, and it appears that the blades struck a tree, or a tree stump. The operator indicated there were no preimpact mechanical problems with the helicopter. On November 16, it was determined by a repair station that all three main rotor blades were unairworthy, and could not be repaired.