Pilot Debrief

ROBINSON HELICOPTER CO R66 near Monticello, GA — 2021-09-16

Final reportERA21FA362
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Date
2021-09-16
Location
Monticello, GA, USA
Aircraft
ROBINSON HELICOPTER CO R66
Registration
N888DV
Category
Helicopter
Highest injury
Fatal
Fatalities
3
Phase of flight
Descent

Probable cause

The pilot’s decision to continue the visual flight rules flight into deteriorating weather conditions during a dark night and over unlit terrain, which resulted in spatial disorientation and a subsequent loss of helicopter control.

NTSB narrative

The pilot, who was also the owner of the company, and a pilot rated passenger were transporting a revenue-paying passenger on a chartered helicopter flight. The flight began on the morning of the accident with an approximately 200 nautical-mile flight to their destination before returning several hours later under visual flight rules. During the return trip, they stopped at an airport to refuel. About halfway through the subsequent flight, they encountered moderate to heavy rain showers. The passenger sent a text message to his spouse stating they landed in a field because “bad storms popped up” and they were waiting for it to blow over before resuming their flight. The message included a photograph that showed a grass field, gray skies, and rain on the helicopter’s window. According to recorded flight track data, after departing the field, the pilot made a series of meandering track changes before proceeding to a nearby small airport where they stayed for about 5 minutes. Weather data indicated that after takeoff, the helicopter remained in areas of low ceilings and rain for the remainder of the flight. By this point in the flight, the sun had set and the end of civil twilight had passed. The helicopter subsequently passed 5 miles west of a city, then passed 2 miles east of a large powerplant before entering a large national wildlife refuge, a remote area covered with dense forest. Shortly thereafter, the helicopter made a series of shallow left and right track changes. During the last 25 seconds of the flight, the helicopter entered a rapidly descending right turn and descended to ground impact. The calculated rate of descend reached nearly 4,000 feet per minute during the descent. The fragmentation of the wreckage and damage to surrounding trees revealed that the helicopter was in a 90° right bank as it came through the trees and impacted terrain. Postaccident examination of the airframe, flight control system components, transmission, rotor system, and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The helicopter was certified for operation in visual meteorological conditions (both day and night) and was not certified for operation in instrument meteorological conditions. While the helicopter was equipped with modern avionics that included tools like synthetic vision, as well as an autopilot system, the pilot’s proficiency in the use of the systems could not be determined based on available information. Some or all the ethanol detected by postmortem toxicological testing in the pilot’s tissue may have been from sources other than consumption. It is unlikely that ethanol or impairment was a factor in the accident. The weather conditions at the time of and preceding the accident consisted of low ceilings, low visibility, and rain with marginal visual meteorological conditions expected through most of the area. Once the helicopter passed the city and powerplant that contained ground reference lighting, and entered the national forest, the dark night conditions and sparse lighting along the flightpath would have made it even more difficult for the pilot to recognize and recover from a loss of control due to spatial disorientation. Based on the wreckage distribution, which was consistent with a high-energy impact, coupled with the known low visibility present at the time of the accident, it is likely that the pilot experienced spatial disorientation and lost control of the helicopter.

Analysis

Primary failure mode
Spatial disorientation
First missed decision gate
Pilot could have chosen to land instead of continuing in poor weather conditions.

NTSB coding

Evidence available

  • ADS-B / radar
  • Photos
  • 20 docket documents
View NTSB final reportView NTSB docket

Docket documents20

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