CHI07LA277

NTSB accident investigation · Bell 47G-5A · Anoka, MN · August 24, 2007

Accident · Minor injuriesLimited investigationFinal report
Date
August 24, 2007, 13:05 local (18:05 UTC)
Place
Anoka, MN
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N25LBBell 47G-5A
Weather
Visual (VMC) · Day
Status
Completed · report April 30, 2008
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20070824019979A
Case key
66562

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 loss of helicopter pitch control for undetermined reasons during the aerial application maneuver and the pilot's inability to control the aircraft during the descent.. A contributing factor to the accident was the soft terrain.

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.

Airframe/component/system failure/malfunctionManeuvering - aerial application
Rotorcraft flight control - failureCause
Loss of control - in flightManeuvering - aerial application
Forced landingDescent - uncontrolled
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - ground
Terrain condition - softFactor
Nose overEmergency landing

Analysis

While maneuvering during an aerial application, the helicopter pilot reported hearing a "CA-BANG" sound followed by a loss of pitch control. The pilot was unable to control the helicopter's rate of descent during the emergency landing and hence impacted on sandy terrain and nosed over. An examination of the wreckage showed no anomalies.

Factual narrative

On August 24, 2007, about 1305 central daylight time, a Bell 47G-5A helicopter, N25LB, operated by Scotts Helicopter Service, sustained substantial damage when it nosed over on impact with terrain during an emergency landing following a reported loss of pitch control near Anoka, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 137 aerial application flight was not operating on a flight plan. The airline transport pilot reported minor injuries. The local flight departed about 1257 from an area about three miles southeast of the accident site.

The pilot said that when he let down into the site and arrested the descent with collective pitch control, he heard a loud "CA-BANG" behind him, like something had failed. At the same time the collective "bottomed out" and the helicopter began to descend. The pilot said that he tried to lift the collective but it would not move. He said he used the cyclic to "get a little altitude back." The pilot was first going to try and land on the road straight ahead, but a car was heading towards him, so he elected to try a run on landing in a park on the blacktop. Due to the lack of pitch control, the pilot was unable to make his intended landing site. He put the helicopter down on the soft ground next to the blacktop where it nosed over.

An examination of the helicopter's flight controls and other systems revealed no anomalies.

Aircraft

Registration
N25LB
Reported as
Bell 47G-5A
Category
Helicopter
Serial number
25102
Airframe hours
13,359.8
Engine
Allison A-250-C10D, 317 horsepower, turbo shaft
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Scotts Helicopter Service Inc
Airworthiness certificate
Special, Restricted (Special); Standard, Normal
Last inspection
100 hour · June 1, 2007
Departed
Anoka, MN
Airport
KANE · Anoka County-Blane 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
61
Injuries
Serious
Certificates
Commercial, Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
August 1, 2007
Seat
Left
Flight hours
8,505 total · 3,150 in this make and model · 6,805 as pilot in command · 56 in the last 90 days · 36 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
300° at 6 knots
Visibility
12 statute miles
Lowest ceiling
5,000 ft broken
Temperature
72 °F, dew point 57 °F
Altimeter
29.90 inHg
Observed at
ANE

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 N25LB · 1

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