A crop-dusting helicopter clipped some power lines Saturday, starting a small fire, and forcing the pilot to make a hard landing in an avocado grove in Valley Center, authorities said.

The pilot, whose name was not available, was not injured, and no one on the ground was hurt.

The chopper went down 10:30 a.m. at McNally and Carney roads, in a rural area about two miles east of Lilac Road, sheriff's Lt. William Donahue said.

The pilot of the Bell 206B helicopter was spraying pesticide on the grove when he clipped the electric lines, Federal Aviation Administration official Ian Gregor said. He said the pilot landed in a clearing in the grove.

Donahue said the helicopter sustained some damage.

FAA records show the helicopter is owned by Aspen Helicopters in Oxnard.

The downed lines knocked out power to about 40 customers in the Valley Center, Pauma Valley and Rincon areas, according to the San Diego Gas & Electric Co.

A blaze sparked by the power lines spread about 250 feet through the grove before Cal Fire firefighters brought the flames under control about 11:25 a.m., said Cal Fire spokesman Mike Mohler.

The crash site was about 20 miles north of Escondido.