NTSB Factual Report

On July 5, 2007, about 0800 central daylight time, N500NC, registered as Hughes 369D helicopter, piloted by a commercial pilot, sustained substantial damage on impact with terrain during a forced landing following a loss of engine power during an aerial application spray run near Comfrey, Minnesota. The local aerial application flight was operating under 14 CFR Part 137. No flight plan was on file. Visual meteorological conditions prevailed at the time of the accident. The pilot, the sole occupant, reported no injuries. The origin and destination of the flight are unknown.

The pilot's accident report, in part, stated:

On the second pass of the second load, and in the middle of

the field headed west, the engine began to spool down in RPM.

I heard the engine sound of lost RPM, at that time my eyes were

on the wires that the aircraft was approaching, N2 Rotor was at

or about the bottom Red Line. My choices were to attempt to

auto rotate across the wires, the road, and the people to the field

beyond. At that split second I decided to attempt the grass area

south of the field. Low N2 and air speed (about 75 mph), lowered

collective attempted a 180 [degree] auto rotation, the engine and

rotor seemed to speed up or surge. I attempted to do the auto as best

as I could. Was able to land square on the skids, but the helicopter

still bounced. The landing gear spread hitting the tanks, and

snapping the uprights above the tanks. At that point, forward leg

stuck in the ground, making the helicopter pitch forward. The blade

in front made contact with the ground. The rotor system came around

cutting the boom faring and tail off.

Federal Aviation Administration Inspectors examined the wreckage. The pressure line which connected to the Pg boss on the fuel control was found finger tight.

NTSB Probable Cause

The loss of engine power due to the loose pressure line during aerial application maneuvers which resulted in a hard forced landing.