SEA08LA020

NTSB accident investigation · Arrow Falcon Exporters OH-58+ · Cougar, WA · November 6, 2007

Accident · Minor injuriesLimited investigationFinal report
Date
November 6, 2007, 08:55 local (16:55 UTC)
Place
Cougar, WA
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N831SDArrow Falcon Exporters OH-58+
Weather
Visual (VMC) · Day
Status
Completed · report February 28, 2008
Report
Approved by Office Director
Parties
Spokane FSDO
FAA report
20071106826469A
Case key
67328

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 pilot's failure to maintain clearance from a nearby tree while performing a hover-climb. Factors include his failure to maintain clearance from his long-line cable, and his likely diverted attention to the entanglement of the cable on the helicopter's wire strike mechanism.

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.

In flight collision with objectHover - out of ground effect
External load cable/hook - entangledFactor
Diverted attentionPilot in commandFactor
Object - tree(s)
Object - other
Clearance - not maintainedPilot in commandCause

Analysis

After lifting off from a dirt pad, the pilot maneuvered the helicopter into a seven to ten foot hover over the fertilizer bucket that was on the end of his long-line. Once centered over the bucket, the pilot began to climb straight up in a hover. As he lifted the bucket off the ground, the helicopter's nose dipped aggressively down, and the pilot became aware that the long-line was caught on the left side of the lower wire strike mechanism. The pilot attempted to put the bucket back on the ground, but the helicopter again dipped forward and to the right. As the pilot continued to attempt to maintain the position of the helicopter while he put the bucket back on the ground, it impacted a nearby Noble fir tree, and fell to the terrain below. According to the pilot and the Federal Aviation Administration Inspector who responded to the scene, there were no anomalies or malfunctions associated with the helicopter's flight controls, engine, or airframe.

Factual narrative

On November 6, 2007, about 0855 Pacific standard time, an Arrow Falcon Exporters OH-58+ helicopter, N831SD, impacted a tree during long-line fertilizer operations near Cougar, Washington. The commercial pilot, who was the sole occupant of the helicopter, received minor injuries, and the helicopter, which is owned and operated by Farm and Forest Helicopter Services, sustained substantial damage. The local 14 CFR Part 137 aerial application flight, which lifted off from a dirt pad about one minute before the accident, was being operated in visual meteorological conditions. No flight plan had been filed.

According to the pilot, after lifting off from the dirt pad, he maneuvered the helicopter into a seven to ten foot hover over the fertilizer bucket that was on the end of his long-line. Once centered over the bucket, the pilot began to climb straight up in a hover. As he lifted the bucket off the ground, the helicopter's nose dipped "aggressively down," and the pilot became aware that the long-line was caught on the left side of the lower wire strike mechanism. The pilot therefore attempted to put the bucket back on the ground, but the helicopter again dipped forward and to the right. As the pilot continued to attempt to maintain the position of the helicopter while he put the bucket back on the ground, it impacted a nearby Noble Fir tree, and fell to the terrain below. The helicopter came to rest on its right side.

According to the pilot and the Federal Aviation Administration Inspector who responded to the scene, there were no anomalies or malfunctions associated with the helicopter's flight controls, engine, or airframe.

The pilot submitted a written statement describing the sequence of events, but he did not submit an NTSB Form 6120.1/2.

Aircraft

Registration
N831SD
Reported as
Arrow Falcon Exporters OH-58+
Category
Helicopter
Serial number
69-16120
Engine
Allison T63-A-720, 400 horsepower, turbo shaft
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Farm and Forest Helicopter Service, Inc.
Airworthiness certificate
Special, Restricted (Special)
Departed
Cougar, WA

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
24
Injuries
Minor
Certificate
Commercial
Instrument ratings
Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
March 1, 2007
Seat
Left
Flight hours
1,500 total · 100 in this make and model · 150 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
39 °F

FAA reports on this event · 1

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