ANC99LA040

NTSB accident investigation · Robinson R-22 · Fairbanks, AK · April 1, 1999

Accident · No injuriesLimited investigationFinal report
Date
April 1, 1999, 10:30 local (14:30 UTC)
Place
Fairbanks, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N8367FRobinson R-22
Weather
Visual (VMC) · Day
Status
Completed · report April 20, 2000
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19990401002879A
Case key
46045

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 NTSB’s determination of the probable cause, and any contributing factors.

The failure of the pilot to maintain rotor rpm during a downwind turn. A factor in the accident was the inadequate altitude to recover from the loss of rotor rpm.

Analysis

The helicopter pilot turned downwind at 30 feet above the ground. The winds were between 15 knots and 30 knots. The main rotor rpm decayed, and the pilot was unable to regain rpm by lowering the collective, disengaging the engine speed governor, and increasing the throttle. During the ensuing forced landing, the helicopter bounced and rolled onto its side. The pilot stated that he did not have tail rotor authority at the low rotor rpm when the helicopter bounced. The engine was operated on a test stand, and exceeded the minimum power requirements for a serviceable engine. No anomalies were noted with the engine, governor, or governor controller.

Factual narrative

On April 1, 1999, about 1030 Alaska standard time, a Robinson R-22 helicopter, N8367F, sustained substantial damage during a forced landing about 38 miles south of Fairbanks, Alaska. The commercial pilot and sole passenger were not injured. The helicopter was operated by Chena River Aviation under 14 CFR Part 135, conducting wolf captures for the State of Alaska, Department of Fish and Game. The flight departed the Chena Marina Airport in Fairbanks at 0930. Visual meteorological conditions prevailed at the time of the accident, and a company VFR flight plan was filed.

The pilot told the NTSB investigator-in-charge (IIC) during a telephone interview on April 1, that he turned downwind in 15 knots to 30 knots of wind, at 30 feet above the ground to capture a wolf. He noticed the rotor and engine rpm decaying. He attempted to lower the collective, disengage the engine speed governor, and increase the throttle, but the rotor speed continued to decay. The pilot said the low rotor speed warning horn activated during his descent, and he made a forced landing to a clearing. The helicopter bounced, and rolled onto its side. He stated that he did not have tail rotor authority at the low rotor rpm when the helicopter bounced. The pilot estimated seven to ten gallons of fuel remained in the fuel tanks at the time of the accident.

The engine was examined and operated on a test stand at the Robinson Helicopter facility on May 3, 1999. The testing was observed by an NTSB investigator. No anomalies were noted with the governor motor, the governor controller, or the engine. The power level produced throughout the test exceeded the minimum specified by the manufacturer.

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 control - in flightManeuvering
Weather condition - tailwind
Rotor rpm - not maintainedPilot in commandCause
Altitude - inadequatePilot in commandFactor
Forced landingEmergency landing
Roll overEmergency landing
Tail rotor effectiveness - not available

Aircraft

Registration
N8367F
Reported as
Robinson R-22
Category
Helicopter
Serial number
2816
Airframe hours
654
Engine
Lycoming HO-360-J2A, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Part 135
Operator
Chena River Aviation
Registered owner
Troy L. Cambier
Airworthiness certificate
Standard, Normal
Last inspection
Annual · March 24, 1999 · 21 hours before
Departed
AK28 · AK
Flight plan
Company VFR

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
31
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Right
Flight hours
2,900 total · 1,550 in this make and model · 2,500 as pilot in command · 175 in the last 90 days · 56 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
180° at 15 knots, gusting 30
Visibility
10 statute miles
Lowest ceiling
6,000 ft broken
Temperature
19 °F

FAA reports on this event · 1

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