What happened
On March 26, 2013, a Hughes OH-6A helicopter, registration N910WC, crashed into a stock pond at the Walking Cane Ranch near Caddo, Texas. The flight, conducted under Part 91 as a personal flight, originated from the ranch at approximately 1215 central daylight time. Weather conditions at the time were visual meteorological conditions with a 10-mile visibility and winds from 200 degrees at 6 knots.
A witness near the site observed the helicopter fly west, then reverse course toward the east to approach a field adjacent to a stock pond. The witness reported that as the helicopter slowed, a strong gust of wind from the north or northwest caused the aircraft to descend rapidly at a bank angle of 45 degrees or greater. The witness further noted that the helicopter began to spin very quickly, appearing as though the main rotor was stationary, before the aircraft disappeared from view.
The pilot reported approaching the field to land in a location used earlier that day. He attempted to identify wind direction and velocity by looking for dust or smoke but observed none. While establishing a hover approximately 3 to 4 feet above the ground, the pilot attempted to turn the aircraft east-southeast. During this maneuver, the helicopter began to spin, and the pilot was unable to maintain control. The aircraft impacted the stock pond on the passenger side and immediately submerged.
The investigation
Investigators examined the wreckage located in the middle of the stock pond. The fuselage, cabin, instrument panel, tail boom, engine, and main rotor assembly were recovered. The investigation found the following:
- The fuselage structure was crushed and wrinkled in multiple locations, and the left door had separated.
- The main rotor blades remained attached to the hub, though they were bent and wrinkled; one blade had separated from the assembly.
- The engine and transmission assembly showed no anomalies that would have prevented the development of designed power. The compressor, starter/generator, and power turbine rotated freely when manually actuated.
- The driveshaft between the main rotor and transmission had separated, which was consistent with impact damage and overload at a design shear point.
- The tail rotor assembly, including the horizontal and vertical stabilizers, was found to be unremarkable, though the tail rotor blades were covered in mud.
- All flight controls, including the cyclic, collective, and anti-torque pedals, were continuous from the cabin to the engine and empennage.
Findings
An examination of the aircraft's systems revealed no mechanical malfunctions or failures that would have prevented normal operations. The pilot stated that during the maneuver, he failed to apply sufficient left pedal input to maintain control.
The accident resulted in 1 fatal injury and 1 minor injury. The passenger died from drowning, having sustained a head injury during the impact sequence that may have rendered him unable to egress. The pilot was able to exit the submerged aircraft.