LOS ANGELES (AP) — A preliminary report says the pilot of the Los Angeles Fire Department's newest helicopter reported the aircraft made uncommanded movements before hitting trees while making a water drop on a wildfire.

The National Transportation Safety Board said Thursday that the Leonardo AW139 helicopter was substantially damaged but the crew was not injured in the Sept. 2 accident.

The report says the pilot was in a descending flight profile about 100 feet above trees at about 40 knots when the helicopter began an uncommanded yaw to the right and descent increased.

The pilot released the water and the helicopter continued to yaw and descend. The pilot reported he had little positive control before hitting the trees. The yaw decreased and the pilot regained control, then made an emergency landing.