SEA98LA013

NTSB accident investigation · Bell 206B · Forest Grove, OR · November 8, 1997

Accident · No injuriesLimited investigationFinal report
Date
November 8, 1997, 12:20 local (20:20 UTC)
Place
Forest Grove, OR
Injuries
1 uninjured
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N101LFBell 206B
Weather
Visual (VMC) · Day
Status
Completed · report May 4, 1998
Report
Approved by Office Director
FAA report
19971108032629A
Case key
42735

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

Excessive deceleration of the helicopter by the pilot-in-command, resulting in an in-flight main rotor blade strike on the helicopter's external load line and subsequent main rotor separation. Downhill terrain which led to a descending approach to the pickup point was a factor.

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 objectManeuvering
Terrain condition - downhillFactor
Maneuver - excessivePilot in commandCause
External load cable/hook - blade strike
Rotor system,main rotor - separation
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The helicopter was approaching a pick-up area for a load of Christmas trees. The approach was over a tree-lined ridge and down into a basin. The pilot reported that while decelerating, he heard a loud bang. Warning horns and lights went off as the helicopter turned to the left and rolled right, subsequently colliding with trees and terrain. A witness on the ground stated that as the helicopter was descending, the long line swung forward and straight up in front of the cabin. The main rotor blades instantly separated and the helicopter started to descend. The witness heard a loud screaming sound, then a loud explosion, and observed the helicopter come apart in mid-air. The cabin continued in the same direction that it was traveling and turned up-side down and collided with trees and terrain. The tail section separated and collided with terrain near where the witness was standing. Cable marks were found on one main rotor blade and one tail rotor blade. The load line itself was severed from the helicopter, and the load line hook displayed severe impact damage signatures.

Factual narrative

On November 8, 1997, at 1220 Pacific standard time, a Bell 206B, N101LF, registered to Hillsboro Helicopters, Inc. of Hillsboro, Oregon, was observed to break up in midair and descend in an uncontrolled manner to a collision with the terrain while performing a 14 CFR Part 133 rotorcraft external-load flight near Forest Grove, Oregon. Visual meteorological conditions prevailed at the time. The commercial pilot-in-command was not injured, and the helicopter was destroyed in the accident and an ensuing post-crash fire. The flight had departed Hillsboro, about three hours prior to the accident. The Federal Aviation Administration (FAA) reported no record of a flight plan having been filed for the flight.

In a written statement, the pilot reported that he was returning to the pick-up area for another load. The pilot stated that he was approximately 50 feet above ground level and traveling between 40 and 50 mph when he began the deceleration process. The pilot pulled power back and heard a loud "bang." The pilot stated that warning horns and lights went off as the helicopter turned to the left and rolled right, subsequently colliding with the trees and terrain.

A witness on the ground reported that he was waiting for the helicopter to return for another load and observed the helicopter fly over a ridge line in preparation to descend into the basin. The witness stated that 15 to 16 foot trees lined the ridge. When the helicopter was about 120 yards away from his position, he saw the long line cable and bell swing forward and shoot straight up in front of the cabin. The witness stated that the main rotor blades instantly separated and the helicopter started to descend. The witness heard a loud "screaming" sound, then a loud explosion and observed the helicopter come apart in mid-air. The cabin continued in the same direction that it was traveling and turned up-side down and collided with trees and the terrain. The tail section separated and collided with the terrain near where the witness was standing.

An FAA inspector from the Portland Flight Standards District Office, Hillsboro, Oregon, responded to the accident scene and reported the following findings to the NTSB investigator-in-charge (IIC). The inspector reported that he observed extensive damage to one main rotor blade, cable marks on the other main rotor blade, one severed tail rotor blade with cable marks, and that the load line itself was severed from the helicopter. The inspector also reported that the hook on the load line displayed severe impact damage signatures.

Aircraft

Registration
N101LF
Reported as
Bell 206B
Category
Helicopter
Serial number
2663
Airframe hours
6,547
Engine
Allison 250 C20B, 420 horsepower, turbo shaft
Damage
Destroyed
Fire
On-Ground
Flight
Other work use · Part 133
Registered owner
Hillsboro Helicopters Inc.
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · August 26, 1997 · 100 hours before
Departed
HIO · Hillsboro, OR

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
30
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Right
Flight hours
4,230 total · 1,630 in this make and model · 4,140 as pilot in command · 59 in the last 90 days · 21 in the last 30 days · 9 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
7 statute miles
Lowest ceiling
10,000 ft broken
Temperature
50 °F, dew point 46 °F
Altimeter
30.00 inHg
Observed at
HIO, 6 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.