CEN18LA025

NTSB accident investigation · Robinson Helicopter R44 · Larchwood, IA · November 6, 2017

Accident · Serious injuriesLimited investigationFinal report
Date
November 6, 2017, 13:10 local (19:10 UTC)
Place
Larchwood, IA
Injuries
2 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N7085MRobinson Helicopter R44
Defining event
Maneuvering-hover: Controlled flight into terr/obj (CFIT)
Weather
Instrument (IMC) · Day
Status
Completed · report November 15, 2018
Report
Approved by Office Director
NTSB office
Central Region
Parties
Federal Aviation Administration
FAA report
20171106021059A
Case key
96292

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 loss of situational awareness, which resulted in his failure to maintain adequate clearance from powerlines.

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/maintainedRobinson Helicopter R44: 22 casesAll aircraft: 1,310 casesProbable cause
Object/animal/substance: wireEnvironmental issues › Physical environment · Awareness of conditionRobinson Helicopter R44: 18 casesAll aircraft: 588 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 a helicopter flight to assist with herding cattle that had gotten loose. According to multiple witnesses on the ground, the helicopter impacted powerlines and then terrain. Video of the accident showed the helicopter facing away from the powerlines at the time of the collision with the powerlines. A postaccident examination of the airframe and engine revealed no mechanical anomalies that would have precluded normal operation at the time of the accident. The witnesses on the ground indicated that there was unlimited visibility and no precipitation at the time of the accident. Thus, the pilot was likely focused on the cattle and lost situational awareness regarding the helicopter's proximity to the powerlines, which resulted in the collision with the powerlines and terrain.

Factual narrative

On November 6, 2017, about 1310 central standard time, a Robinson Helicopter R44 helicopter, N7085M, was substantially damaged when it impacted powerlines and then terrain 4.5 miles south of Larchwood, Iowa. The commercial pilot and passenger sustained serious injuries. The aerial observation flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no Federal Aviation Administration (FAA) flight plan had been filed for the flight. The local flight departed about 1300.According to the passenger and witnesses on the ground, the helicopter was assisting in locating and herding 300 cattle that were loose in the area. The helicopter was assisting the ground team to push the cattle towards an open gate directly beneath powerlines. Witnesses on the ground observed the helicopter hovering and as it started to turn, the "tail" of the helicopter hit the powerlines. The helicopter descended to the ground and came to rest on its right side in a corn field. Several witnesses and the passenger stated that the helicopter looked and sounded normal prior to the impact. A video of the accident taken by another witness on the ground showed the helicopter maneuvering near the powerlines, with the nose of the helicopter facing away from the powerlines. The tail of the helicopter impacted the powerlines, followed by the main rotor blades. The helicopter rotated once before impacting the ground. According to a FAA inspector who responded to the accident, the tailboom separated from the fuselage and both main rotors were substantially damaged. An examination of the helicopter, engine, and remaining systems revealed no mechanical anomalies that would have precluded normal operations. An official weather observation taken 18 miles northwest of the accident site reported the weather as wind 060° at 7 knots, visibility 1.5 miles in light snow, overcast skies at 2,300 ft above ground level, temperature -1° C, dewpoint temperature -4°C, and an altimeter of 30.26 inches of mercury. The witnesses on the ground at the accident site characterized the weather as overcast, windy, unlimited visibility, and no precipitation. At the writing of this report, the pilot had no recollection of the accident or the events that led up to the accident.

Aircraft

Registration
N7085M
Reported as
Robinson Helicopter R44
Category
Helicopter
Serial number
0430
Built
1998
Airframe hours
2,042.8
Engine
Lycoming O-540-F185, 250 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial observation · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · June 15, 2017 · 38.6 hours before
Departed
Larchwood, IA
Destination
Larchwood, IA
Equipment
Handheld GPS

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
45
Injuries
Serious
Certificate
Commercial
Medical
Class 2, Without waivers/limitations
Last flight review
April 15, 2017
Seat
Right
Restraint
3-point
Flight hours
5,200 total · 5,000 in this make and model

Weather

Conditions
Instrument (IMC) · Day
Wind
60° at 7 knots
Visibility
1.5 statute miles
Lowest ceiling
2,300 ft overcast
Temperature
30 °F, dew point 25 °F
Altimeter
30.26 inHg
Observed at
KFSD, 18 nm away

Docket · 4

The files NTSB released with the investigation on May 17, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 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.