ANC06LA025

NTSB accident investigation · Robinson R44 · Ilimana, AK · March 12, 2006

Accident · No injuriesLimited investigationFinal report
Date
March 12, 2006, 13:20 local (17:20 UTC)
Place
Ilimana, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N7528ZRobinson R44
Weather
Instrument (IMC) · Day
Status
Completed · report October 31, 2006
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
Anchorage FSDO
FAA report
20060312003399A
Case key
63341

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 pilot's continued flight into adverse weather conditions, and his spatial disorientation and loss of control during a subsequent landing attempt. Factors associated with the accident are flat light and whiteout conditions, fog, and snow-covered 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.

In flight encounter with weatherManeuvering
Light condition - otherFactor
Weather condition - whiteoutFactor
Weather condition - fogFactor
Flight into known adverse weather - continuedPilot in commandCause
In flight collision with terrain/waterLanding - flare/touchdown
Terrain condition - snow coveredFactor
Spatial disorientationPilot in commandCause
Aircraft control - not maintainedPilot in commandCause
Roll overLanding - flare/touchdown

Analysis

The commercial helicopter pilot was flying one passenger on an on-demand, Title 14, CFR Part 135 air taxi flight to a remote site in an area surrounded by snow-covered, flat, featureless terrain. Low fog, reduced visibility, and flat light conditions reduced his ability to discern a horizon or terrain. He said that the visibility deteriorated to about 1 or 2 miles, and he was unable to discern any topographic features on the snow-covered terrain, and he elected to make a precautionary landing to wait for better visibility. After about 10 minutes, he decided to continue to his destination. Just after takeoff, flat light conditions again reduced his ability to recognize any topographical features on the snow-covered terrain. He reported that while he was attempting to establish a stable hover, and erroneously believing that the helicopter was not moving, the helicopter's right skid struck the snow-covered terrain. The helicopter rolled to the right, and the main rotor blades struck the ground. As the main rotor blades struck the ground, the helicopter rolled onto its right side. The helicopter sustained substantial damage to the fuselage, tail boom assembly, and the main and tail rotor drive systems. The pilot reported that there were no preaccident mechanical anomalies with the helicopter.

Factual narrative

On March 12, 2006, about 1320 Alaska standard time, a skid-equipped Robinson R44 helicopter, N7528Z, sustained substantial damage after colliding with snow-covered terrain while maneuvering to land, about 10 miles west of Iliamna, Alaska. The helicopter was being operated as a visual flight rules (VFR) on-demand charter flight by Pollux Aviation, Wasilla, Alaska, under Title 14, CFR Part 135, when the accident occurred. The certificated commercial pilot and the sole passenger were not injured. Instrument meteorological conditions prevailed at the accident site. Visual meteorological conditions prevailed at the time of departure, and company flight following procedures were in effect. The flight originated about 1305, from the Iliamna Airport, Iliamna, and was en route to a remote, off-airport site.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on March 12, the pilot said that after departing from the Iliamna Airport, he flew west, en route to a remote drill site. According to the pilot, low fog, reduced visibility, and flat light conditions reduced his ability to discern a horizon or terrain. He said that the visibility deteriorated to about 1 or 2 miles, and he was unable to discern any topographic features on the surface of the flat, featureless, snow-covered terrain, and he elected to make a precautionary landing to wait for better visibility. After remaining on the ground for about 10 minutes, he decided to fly towards his destination. He said that just after takeoff, as the helicopter moved forward, flat light conditions and blowing snow, contributed to his inability to recognize any topographical features. He reported that while he was attempting to establish a stable hover, and erroneously believing that the helicopter was not moving, the helicopter's right skid struck the snow-covered terrain. The helicopter subsequently rolled to the right, and the main rotor blades struck the ground. As the main rotor blades struck the ground, the helicopter continued to roll onto its right side. The helicopter sustained substantial damage to the fuselage, tail boom assembly, and the main and tail rotor drive systems.

In a written statement included in the NTSB Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the operator, dated March 20, 2006, the pilot reported weather conditions at the time of the accident to be, in part: Wind, calm; visibility, 3 statute miles; ceiling and clouds, 100 feet scattered, 200 feet overcast; temperature, 23 degrees F.

Aircraft

Registration
N7528Z
Reported as
Robinson R44
Category
Helicopter
Serial number
10384
Airframe hours
1,360
Engine
Lycoming IO-540, 205 horsepower, reciprocating
Damage
Substantial damage
Flight
Part 135
Registered owner
Pollux Aviation LTD
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · February 1, 2006
Departed
ILI · Iliamna, AK
Destination
ILI · Ilimana, 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
47
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Seat
Right
Flight hours
4,600 total · 1,800 in this make and model · 4,530 as pilot in command · 60 in the last 90 days · 50 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Day
Wind
Calm
Visibility
3 statute miles
Lowest ceiling
200 ft overcast
Temperature
23 °F

FAA reports on this event · 1

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