FTW99LA191

NTSB accident investigation · Bell OH-58A · Bastrop, LA · July 16, 1999

Accident · No injuriesLimited investigationFinal report
Date
July 16, 1999, 08:34 local (13:34 UTC)
Place
Bastrop, LA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N9254RBell OH-58A
Weather
Visual (VMC) · Day
Status
Completed · report June 22, 2000
Report
Approved by Office Director
FAA report
19990716047779A
Case key
46803

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 failure of the refueling truck's filter to separate water resulting in the water contamination in the helicopter's fuel system and subsequent loss of engine power. A factor was the lack of suitable terrain for the forced landing.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - nonmechanicalCruise
Airport facilities,refueling truck/equipment - otherCause
Fuel system,tank - contamination,waterCause
Forced landingDescent - emergency
Autorotation - initiatedPilot in command
In flight collision with objectDescent - emergency
Terrain condition - none suitableFactor
Object - tree(s)

Analysis

The helicopter experienced a total loss of engine power due to a contaminated fuel system. Days prior to the accident flight, the refueling truck had been contaminated with water, and the accident helicopter had been filled with the contaminated fuel. The pilot and ground crew became aware of the situation and sumped both the truck and the helicopter. The pilot thought that the helicopter's fuel system was free of the contaminated fuel. During the accident flight, the engine lost power, the pilot initiated an autorotation, and the helicopter impacted pine trees. The FAA inspector observed water and algae in the helicopter's fuel filters. The operator stated that the refueling truck's water filter failed to separate the water from the fuel during the fueling operations. After the accident, the operator installed water/fuel separators in all the refueling trucks in addition to the filters that were already in place as an extra measure of safety.

Factual narrative

On July 16, 1999, approximately 0834 central daylight time, a Bell OH-58A helicopter, N9254R, was substantially damaged when it impacted terrain during a forced landing following a total loss of engine power near Bastrop, Louisiana. The instrument-rated commercial pilot, sole occupant of the helicopter, was not injured. The helicopter was registered to and operated by North Star Helicopters Inc., of Jasper, Texas. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 137 aerial application flight and no flight plan was filed. The local flight originated from a private staging area near Bastrop, Louisiana.

According to the pilot, he had completed his 30th application of arsenal, a chemical used for aerial application flights, and was returning to the staging area. The helicopter was flying at 150 feet agl when the engine power "gradually decreased," and the engine lost total power. The pilot stated that the "ENGINE OUT" warning light illuminated. He initiated an autorotation, during which the helicopter contacted pine trees that were approximately 20 feet tall. The helicopter came to rest on its left side in the pine trees. The tail boom, the left skid, and the main rotor blades were damaged.

The FAA inspector, who visited the accident site, reported that the helicopter's fuel system was contaminated with water and algae. He stated that water and algae were found in the helicopter's fuel filters.

According to the operator, the refueling truck had been contaminated with water a few days prior to the accident. The accident helicopter was fueled from the contaminated truck. The ground crew and pilot became aware of the situation and sumped the helicopter's fuel tanks and the refueling truck. The pilot thought he had sumped all of the water out of the helicopter's fuel tanks. The pilot took the helicopter on the first flight since the discovery of contamination and experienced the ensuing engine failure. The operator stated that the filter on the refueling truck had failed to separate the water from the fuel during the fueling operations. The operator reported that all of its refueling trucks have since been modified with additional water/fuel separators as an extra measure of safety.

Aircraft

Registration
N9254R
Reported as
Bell OH-58A
Category
Helicopter
Serial number
71-20844
Airframe hours
3,777
Engine
Allison C-20B-T63, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
North Star Helicopter Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · June 15, 1999 · 66 hours before
Departed
NONE

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
41
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Right
Flight hours
12,500 total · 500 in this make and model · 300 in the last 90 days · 150 in the last 30 days · 8 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
6 statute miles
Lowest ceiling
None
Temperature
82 °F, dew point 73 °F
Altimeter
30.00 inHg
Observed at
MLU, 18 nm away

FAA reports on this event · 1

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