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NTSB accident investigation · Md Helicopter 369 · Summersville, SC · June 26, 2019

Accident · Minor injuriesData collectionFinal report
Date
June 26, 2019, 16:37 local (20:37 UTC)
Place
Summersville, SC
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N500SCMd Helicopter 369
Defining event
Maneuvering-hover: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report May 21, 2020
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20190626006419A
Case key
99819

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

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.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Communication (personnel): lack of communicationPersonnel issues › Task performance · CopilotAll aircraft: 84 casesProbable cause
Rotorcraft flight control: tail rotor control systemAircraft › Aircraft propeller/rotor · Incorrect use/operationAll aircraft: 13 casesProbable cause
Performance/control parametersAircraft › Aircraft oper/perf/capability · Not attained/maintainedAll aircraft: 1,269 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

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.

Factual narrative

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 NoticeOSN2019-004 in the docket).

Aircraft

Registration
N500SC
Reported as
Md Helicopter 369 (E)
Category
Helicopter
Serial number
0334E
Built
1989
Airframe hours
11,719.1
Engine
Rolls Royce RR250-C20B, 420 horsepower, turbo shaft
Damage
Substantial damage
Fire
On-Ground
Flight
Aerial observation · Part 91
Operator
South Carolina Law Enforcement Division
Registered owner
South Carolina Law Enforcement Division
Airworthiness certificate
Unknown
Last inspection
100 hour · June 11, 2019
Departed
DYB · Summersville, SC
Destination
DYB · Summersville, SC
Airport
DYB · Summerville
Equipment
Satellite tracking device, Electronic multifunction display, ADS-B

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
46
Injuries
Minor
Certificate
Commercial
Medical
Class 2, Without waivers/limitations
Last flight review
February 20, 2019
Seat
Left
Restraint
4-point
Flight hours
836 total · 759 in this make and model · 708 as pilot in command · 51 in the last 90 days · 27 in the last 30 days · 5 in the last 24 hours
Role
Co-pilot
Age
63
Injuries
None
Certificates
Commercial, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Medical
Class 2, With waivers/limitations
Seat
None
Restraint
None

Weather

Conditions
Visual (VMC) · Day
Wind
320° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
86 °F, dew point 68 °F
Altimeter
30.11 inHg
Observed at
KDYB

Docket · 9

The files NTSB released with the investigation on January 3, 2020, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.8 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.