WPR10LA446

NTSB accident investigation · Bell 47G · Salinas, CA · September 3, 2010

Accident · Serious injuriesLimited investigationFinal report
Date
September 3, 2010, 06:00 local (13:00 UTC)
Place
Salinas, CA
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N4427FBell 47G
Defining event
Enroute: VFR encounter with IMC
Weather
Instrument (IMC) · Day
Status
Completed · report December 19, 2011
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20100903045679A
Case key
77190

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 visual flight rules flight into instrument meteorological conditions, which resulted in his spatial disorientation and loss of helicopter control.

Findings · 4

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.

Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotBell 47G-5: 4 casesAll aircraft: 9,295 casesProbable cause
Ceiling/visibility/precip: low visibilityEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeBell 47G-5: 1 caseAll aircraft: 175 cases

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

After taking off on a visual flight rules flight in instrument meterological conditions, with a reported 2 1/2 miles visibility with mist and overcast clouds at 100 feet, the pilot proceeded westbound about 50 feet above ground level (agl) then, while approaching an interstate highway, climbed to 100 feet agl in order to avoid power lines. During the climb, the helicopter entered the fog. The pilot stated that after entering the fog he turned on the landing light, which blinded him and caused him to become disoriented as he attempted to make a 180-degree turn back to the airport. The pilot added that he subsequently lost control of the helicopter and impacted a highway guardrail with the tail section of the helicopter. The helicopter then came to rest inverted and partially in the southbound lane of the highway. The pilot reported no helicopter mechanical failures or malfunctions. A truck driver who witnessed the accident reported that the forward visibility was about 250 feet at the time of the accident.

Factual narrative

On September 3, 2010, about 0600 Pacific daylight time, a Bell 47G-5 helicopter, N4427F, was substantially damaged following impact with terrain near Salinas, California. The commercial pilot, the sole occupant, was seriously injured. Gomes Farm Air Service of Salinas, was operating the helicopter under the provisions of Title 14 Code of Federal Regulations Part 91. Instrument meteorological conditions prevailed at the time of the accident, and a flight plan was not filed. The repositioning flight had departed the Salinas Municipal Airport (SNS) about 0550, with its destination being an off-airport work site about 3 miles west of SNS. According to a Federal Aviation Administration (FAA) aviation safety inspector who conducted a telephone interview with the pilot shortly after the accident, the pilot stated that he was flying about 50 feet above the ground and was concerned about the power lines that were hidden by the fog. The pilot reported that he then climbed up to about 80 feet above ground level (agl), which put him in the fog, and when he turned on the landing light in an attempt to illuminate the ground references and identify the power lines, it caused a temporary blinding condition that caused him to become disoriented. The pilot stated that he then attempted a 180-degree turn toward the airport, which resulted in a loss of control and impact with the highway pavement. The pilot reported no mechanical problems with the helicopter. In a written report submitted to the National Transportation Safety Board investigator-in-charge (IIC) several days after the accident, the pilot reported that abeam the airport’s control tower at an altitude of about 75 feet mean sea level (msl) and after turning west toward the interstate highway that borders the airport on the west, he could clearly see a [sugar plant] about 2 miles away. The pilot stated that after reaching the interstate highway he climbed to 100 feet msl and remained clear of clouds, with visibility “2 miles plus.” The pilot revealed that when the helicopter was over the interstate highway’s median strip between the north and southbound lanes, visibility began to deteriorate. The pilot reported that at this time he decided to turn around and return to the airport, as well as to descend in an attempt to re-establish visual contact [with ground references]. The pilot stated that during the descent and course reversal the tail section of the helicopter collided with a guard rail on the highway. The helicopter subsequently impacted the highway pavement and came to rest inverted partially in a southbound lane. The helicopter sustained substantial damage to its airframe. A truck driver who was traveling southbound on the interstate highway reported seeing the helicopter approaching her position from the right side; it was moving from side to side. The witness stated that the helicopter subsequently impacted the terrain and rolled over, coming to rest partially inverted. The witness added thatthe forward visibility at the time of the accident was about 250 feet, and it was also very foggy. At 0546, a special observation was reported by the SNS Automated Surface Observing System (ASOS), which revealed wind calm, visibility 2 ½ miles, mist, overcast clouds at 100 feet, temperature 13 degrees Celsius, dew point 12 degrees Celsius, and an altimeter setting of 29.96 inches of Mercury. At 0553, the SNS ASOS reported wind calm, visibility 2 ½ miles, mist, overcast clouds at 100 feet, temperature 13 degrees Celsius, dew point 12 degrees Celsius, and an altimeter setting of 29.97 inches of Mercury.

Aircraft

Registration
N4427F
Reported as
Bell 47G (5)
Category
Helicopter
Serial number
7971
Airframe hours
7,936
Engine
Lycoming VO435, 260 horsepower, reciprocating
Damage
Substantial damage
Flight
Positioning · Part 91
Operator
Frank Gomes
Registered owner
Gomes Farm Air Service Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Continuous airworthiness · July 30, 2010 · 0 hours before
Departed
SNS · Salinas, CA
Destination
SNS · Salinas, CA
Airport
SNS · Salinas Municipal Airport

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
62
Injuries
Serious
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Without waivers/limitations
Last flight review
November 18, 2008
Seat
Left
Flight hours
15,928 total · 15,928 as pilot in command · 120 in the last 90 days · 50 in the last 30 days

Weather

Conditions
Instrument (IMC) · Day
Wind
Calm
Visibility
2 statute miles
Lowest ceiling
100 ft overcast
Temperature
55 °F, dew point 54 °F
Altimeter
29.96 inHg
Observed at
SNS, 2 nm away

Docket · 5

The files NTSB released with the investigation on November 3, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 795 KB 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.

Other investigations on N4427F · 1

Matched to the same aircraft by N-number and date.