Summersville, SC, USA
N500SC
Md Helicopter 369
The pilot, seated in the left seat, reported that he taxied and landed the helicopter on a taxiway after completing a mission. After landing, the copilot, seated in the right seat, disembarked with the passenger to request fuel from the fixed-base operator. The copilot returned to the helicopter without boarding and instructed the pilot to reposition the helicopter to the airport's refueling station because the fuel truck was inoperative. Once the copilot was clear of the helicopter, the pilot brought the helicopter to a hover, but the helicopter began to spin clockwise. He then applied left pedal, but the helicopter continued to spin and climbed about 7 ft above ground level. The pilot stated that, after two revolutions, he realized that the right-seat, left antitorque pedal was "chocked" and added that he was not aware that the copilot had "chocked" the pedals. He immediately initiated an autorotation, but the helicopter's tail rotor and main rotor blades struck the ground. The copilot reported that, after exiting the cockpit, while the pilot had positive control of the flight controls, he chocked the pedals on the right side by removing the left antitorque pedal, rotating it 180°, and reinstalling it, which prevented full travel of the left antitorque pedal on both sides of the cockpit. He added that he did not tell the pilot he had chocked the pedals and that he did not know why he chocked the pedals. The helicopter sustained substantial damage to the main and tail rotor systems and tailboom. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
The helicopter's pilot, seated in the left seat, reported that he taxied and landed the helicopter on a taxiway after completing a mission with a copilot onboard. After landing, the copilot, seated in the right seat, disembarked with the passenger, to request fuel from the fixed base operation. The copilot returned to the helicopter and without boarding, instructed the pilot to reposition the helicopter to the airport's refueling station because the fuel truck was inoperative. Once the copilot was clear of the helicopter, the pilot brought the helicopter to a hover, but the helicopter began to spin clockwise. He then applied left pedal, but the helicopter continued to spin and climbed about 7 ft above ground level. After two revolutions, the pilot realized that the right seat, left hand anti-torque pedal was "chocked." He immediately initiated an autorotation, but the helicopter's tail rotor and main rotor blades struck the ground. The copilot reported that, after exiting the cockpit, while the pilot had positive control of the flight controls, he "chocked" the pedals on the right side, by removing the left-hand anti-torque pedal, rotated it 180°, and reinstalled it. This action prevents full travel of the left anti-torque pedal on both sides of the cockpit. He did not tell the pilot he had chocked the pedals, and the pilot added that he was not aware that the copilot had "chocked" the pedals. The copilot added that he did not know the reason why he "chocked" the pedals. The helicopter sustained substantial damage to the main rotor system, tail rotor system and tailboom. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. A senior leadership official for the operator reported that "chocking the pedals" is a common, unwritten practice utilized when both pilots exit the helicopter while the engine is running. He added that there was a consensus between both full time and part-time pilots approving the "chocking of pedals", although the action is not approved by the manufacturer. Conversely, the pilot, who is also the unit safety officer, reported that he did not agree with the practice but did not express his concern to management and went along it, adding that the practice and the organizational culture does not reflect a Just Safety Culture. According to a manager, a safety management systems (SMS) manual was created 2 years earlier, but its "Hazard Identification and Analysis" and "Safety Risk Assessment and Mitigation" processes were not utilized to determine the risks associated with "chocking the pedals." The manager added that the SMS program is not properly understood nor utilized by all pilots or management and seen as another program created by upper management to satisfy a requirement. According to the manufacturer, "locking" the pedals while the engine is running, is not an approved procedure (refer to the Operational Safety Notice OSN2019-004 in the docket).
The copilot’s disabling of the flight controls of an operating helicopter without telling the pilot on the controls, which resulted in a subsequent loss of control and collision with terrain.
Source: NTSB Aviation Accident Database
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