CEN17LA314

NTSB accident investigation · Hughes 369D · Villa Grove, CO · August 10, 2017

Accident · Serious injuriesLimited investigationFinal report
Date
August 10, 2017, 14:00 local (20:00 UTC)
Place
Villa Grove, CO
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N58424Hughes 369D
Defining event
Maneuvering-low-alt flying: Low altitude operation/event
Weather
Visual (VMC) · Day
Status
Completed · report November 6, 2019
Report
Approved by Office Director
NTSB office
Central Region
Parties
Federal Aviation Administration
FAA report
20170810010359A
Case key
95801

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

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Probable cause

The pilot’s failure to maintain main rotor clearance from a power line tower during low-level maneuvering.

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.

Performance/control parameters: altitudeAircraft › Aircraft oper/perf/capability · Not attained/maintainedHughes Helicopters HUGHES 369D: 10 casesAll aircraft: 1,310 casesProbable cause
Object/animal/substance: poleEnvironmental issues › Physical environment · Effect on operationHughes Helicopters HUGHES 369D: 1 caseAll aircraft: 142 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 commercial pilot was conducting external load operations in the helicopter to assist power line construction. While maneuvering the helicopter away from a tower at low altitude, the pilot flew the helicopter to the right while planning on backing up at the same time. The helicopter's speed to the right was faster than he had planned. Subsequently, the helicopter's main rotor hit a tower before it came into the pilot's view, and the helicopter then impacted terrain. The pilot reported that the helicopter did not have any mechanical malfunctions or failures that would have precluded normal operation. Given the pilot's statement, it is likely that he was not adequately monitoring the environment during low-level maneuvering among power line towers and failed to see a tower before the main rotors hit it.

Factual narrative

"***This report was modified on June 3, 2019. Please see the docket for this accident to view the original report.*** On August 10, 2017, about 1400 mountain daylight time, a Hughes 369D helicopter, N58424, had its tail rotor impact a powerline near Villa Grove, Colorado. The pilot received serious injuries. The helicopter sustained substantial tailboom and fuselage damage. The helicopter was registered to Quicksilver Air Inc. and operated by Patrol Helicopters Inc. as a 14 Code of Federal Regulations Part 133 rotorcraft external load flight. Day visual meteorological conditions prevailed in the area about the time of the accident, and the flight was not operated on a flight plan. The local flight originated from a field near the accident site. According to the pilot's accident report, the purpose of the flight was to assist power line construction. After pulling a sock line through several structures, the helicopter was flown inside an angle tower. As the pilot was flying the helicopter away from the angle tower, he flew the helicopter to his right while planning on backing up at the same time. The helicopter's speed to the right was faster than planned. He stated that the helicopter's main rotors contacted a tower before it came into view, and the helicopter subsequently "crashed." The pilot indicated that the helicopter did not have any mechanical malfunctions. The pilot was not wearing a helmet.

Aircraft

Registration
N58424
Reported as
Hughes 369D
Category
Helicopter
Serial number
1090593D
Built
1979
Engine
Rolls Royce 250 C20B, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
External load · Part 133
Operator
Patrol Helicopters Inc.
Registered owner
Quicksilver Air Inc
Airworthiness certificate
Standard, Normal
Departed
Villa Grove, CO

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
69
Injuries
Serious
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Unknown
Last flight review
December 8, 2016
Seat
Left
Restraint
4-point
Flight hours
19,500 total · 16,000 in this make and model · 18,500 as pilot in command · 67.3 in the last 90 days · 50.5 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
79 °F, dew point 45 °F
Altimeter
30.32 inHg
Observed at
KALS, 49 nm away

Docket · 1

The files NTSB released with the investigation on May 1, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 8.1 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.