Accident Details
On May 10, 2008, at 1215 central daylight time, a Robinson R22 Mariner helicopter (registration N8316D) was substantially damaged when it struck the water while maneuvering over Lake Travis in Austin, Texas. The commercial pilot and pilot-rated passenger were not injured. The helicopter was operated by Boat Pix of West Palm Beach, Florida, and was registered to a private company. The flight departed Austin-Bergstrom International Airport around 1030 and was destined for Lake Travis. No flight plan was filed, and visual meteorological conditions prevailed.
Witness Accounts
Several witnesses observed the helicopter flying at low altitude over boats. One witness reported that the helicopter flew over their boat, then made a hard right bank turn, descended, and bounced its pontoons on the water, eventually flipping upside down. Another witness saw the helicopter performing what they described as "aeronautic maneuvers" at 6-8 feet above the water, including sharp pull-ups and right banks. After hearing a slapping noise, this witness saw the helicopter's pontoons floating.
Pilot Statement
The pilot stated that while tracking a boat approximately 100 feet above ground level, he executed a right-hand turn and noticed a decrease in rotor RPM. The low rotor RPM horn activated and the governor light began flashing. He attempted a low rotor RPM recovery by lowering the collective, increasing throttle, and turning into the wind. He determined they could not regain RPM before hitting the water and used remaining rotor RPM to slow the descent. The helicopter struck the water and bounced, then a boat wake washed over the floats, causing the helicopter to roll forward and flip over. The pilot-rated passenger provided a similar account.
Examination
The helicopter was recovered and the governor controller was sent to Robinson Helicopter Company for testing. Examination on a calibrated test bench showed the controller met all acceptance criteria for a new or overhauled unit. No visible external damage was noted, and the internal components were not inspected due to the unit passing the tests.
Pilot Information
The pilot held a commercial pilot certificate and a certified flight instructor rating for helicopters. His last second-class FAA medical was issued on March 10, 2008. He reported 895.4 total flight hours, with 871 hours in the same make and model.
Weather Conditions
Weather at Austin-Bergstrom International Airport at 1153 included wind from 190 degrees at 12 knots gusting 17 knots, visibility 2 miles with haze, broken clouds at 1,800 feet, overcast at 2,200 feet, temperature 79°F, dew point 41°F, and barometric pressure 29.75 inches of mercury.