Pilot Was Practicing Night Water Bucket Operations

The NTSB has released a probable cause report from an accident which occurred August 4 last year that fortunately resulted only in a minor injury to the pilot involved.

According to the report, the pilot said that he was hovering over a lake at night while practicing water bucket operations. He was using the helicopter’s landing light and newly installed movable searchlight positioned to shine underneath and toward the left side of the helicopter for illumination.

He reported that he was able to see the shoreline, horizon, and the texture on the water during these operations. He reported that, during the third load, he transitioned his sight “forward and inside to the instrument panel” and that, while he was scanning the instrument panel, he “noticed the rotor disk dipping toward the water.” The main rotor blades then struck the water, followed by the helicopter impacting the water. The cockpit filled with water as the helicopter rolled upside-down and began to sink.

The pilot reported that, while he was egressing from the cockpit underwater, he felt his “helmet tug backwards and…realized the communications cord was still attached to the helicopter.” The pilot removed his helmet, surfaced, and swam to the shore without further incident. The helicopter was recovered from the lake, and an examination of the helicopter revealed substantial damage to the fuselage, the main rotor system, and the tail boom. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

The NTSB concluded that the determines the probable cause of this accident to be the pilot’s failure to maintain altitude and a level attitude while hovering over water at night during an external load operation, which resulted in the helicopter’s main rotor contacting the surface of the water.

FMI: www.ntsb.gov