Sunday, May 10, 2020

Loss of Control in Flight: Robinson R44 II, N511CC; accident occurred April 19, 2018 at Chena Marina Airport (AK28), Fairbanks, Alaska

View of the snowbank and trees. 
Federal Aviation Administration 

 View of the recovered helicopter with substantial damage.
Federal Aviation Administration
AK28 Pad Drawing

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Fairbanks, Alaska

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Fairbanks, AK
Accident Number: ANC18LA032
Date & Time: 04/19/2018, 1600 AKD
Registration: N511CC
Aircraft Damage: Substantial
Defining Event: Loss of control in flight
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Personal 

On April 19, 2018, about 1600 Alaska daylight time, a tundra/snow board-equipped Robinson R44 Raven II helicopter, N511CC, impacted trees and a snowbank while conducting a hover turn at the Chena Marina Airport (AK28), Fairbanks, Alaska. The private pilot, the sole occupant, sustained no injury and the helicopter sustained substantial damage. The helicopter was registered to Godspeed Leasing, LLC, and was operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a visual flight rules personal flight. Day visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The helicopter lifted off from the helicopter landing pad about 1600.

The helicopter was stationed on an unmarked asphalt pad surrounded by gravel. The pad was connected to private hangar where the helicopter was kept inside. The pilot reported the purpose of the flight was to fly to a remote cabin. Prior to bringing the helicopter to a hover, he received the automatic terminal information system (commonly known as "ATIS") information from the Fairbanks International Airport (FAI), Fairbanks, Alaska.

The pilot, stationed in the right seat, picked up the helicopter from the pad, to about a 10-ft above ground level hover profile. The pilot then executed a hovering turn to the south, with the intent of facing the east. He reported that as the helicopter was turning, a gust of wind from the northeast "pushed" the helicopter into the trees. The main rotor blades impacted various spruce and birch trees and the helicopter subsequently impacted a snowbank near the trees and the ground. The pilot was able to egress from the helicopter without further incident.

Two Federal Aviation Administration (FAA) aviation safety inspectors from the Fairbanks Flight Standards District Office responded to the accident site on the day of the accident to interview the pilot, photograph the wreckage, and measure the dimensions of the pad and the surrounding area as shown below in figure 1. The pad was about 10 ft wide by 45 ft long. The distance from the center of the pad to the snowbank, was about 40 ft, and to the trees it was about 44 ft.

Figure 1 – View of the pad at AK28, along with the snowbank and trees (courtesy of the FAA).

The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. 

Pilot Information

Certificate: Private
Age: 65, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land; Single-engine Sea
Seat Occupied: Right
Other Aircraft Rating(s): Helicopter
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 3 Without Waivers/Limitations
Last FAA Medical Exam: 04/20/2018
Occupational Pilot: No
Last Flight Review or Equivalent: 01/01/2016
Flight Time:  (Estimated) 4300 hours (Total, all aircraft), 1000 hours (Total, this make and model), 4280 hours (Pilot In Command, all aircraft), 78 hours (Last 90 days, all aircraft), 43 hours (Last 30 days, all aircraft), 2 hours (Last 24 hours, all aircraft) 

Aircraft and Owner/Operator Information

Registration: N511CC
Model/Series: R44 II
Aircraft Category: Helicopter
Year of Manufacture: 2003
Amateur Built:No 
Airworthiness Certificate: Normal
Serial Number: 10173
Landing Gear Type: Skid;
Seats: 4
Date/Type of Last Inspection:  Annual
Certified Max Gross Wt.: 2500 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time:
Engine Manufacturer: Lycoming Engines
ELT: C126 installed, activated, did not aid in locating accident
Engine Model/Series: IO-540 Series
Registered Owner: Godspeed Leasing, LLC
Rated Power: hp
Operator: On file
Operating Certificate(s) Held:None  

The Robinson R-44 II Pilot's Operating Handbook (POH) states that for the main rotor system, the radius is 16.5 ft and the diameter is 33 ft. The POH further states that from the front of the fuselage to the end of the tail rotor system guard, the length is 29.41 ft.

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PAFA, 432 ft msl
Distance from Accident Site: 1 Nautical Miles
Observation Time: 2353 UTC
Direction from Accident Site: 117°
Lowest Cloud Condition: Scattered / 20000 ft agl
Visibility:  10 Miles
Lowest Ceiling:
Visibility (RVR):
Wind Speed/Gusts: 12 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 350°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 29.44 inches Hg
Temperature/Dew Point: 3°C / -11°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Fairbanks, AK (AK28)
Type of Flight Plan Filed: None
Destination: Unknown, AK (None)
Type of Clearance: None
Departure Time: 1600 AKD
Type of Airspace: Class D 

ATIS information Romeo, from FAI at 1553 (2353 Zulu), stated the wind direction originated from 330° at 11 kts. ATIS information Sierra, from FAI at 1653 (0053 Zulu), stated the wind direction originated from 340° at 12 kts.

There were no reports of any wind gusts in the ATIS information. FAI is at an elevation of 439 ft above mean sea level and is about 1 mile east of AK28.

Airport Information

Airport: CHENA MARINA (AK28)
Runway Surface Type: Asphalt
Airport Elevation: 427 ft
Runway Surface Condition: Dry
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: None

The pad utilized, along with AK28, are private use facilities. 

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire:None 
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 64.813889, -147.921944 (est)

The helicopter sustained substantial damage to the main rotor system, the fuselage, the tail boom, and the tail rotor system as shown below in figure 2.

Figure 2 – View of the recovered helicopter with substantial damage (courtesy of the FAA).

Additional Information

Hovering Turns

The FAA Helicopter Flying Handbook FAA-H-8083-21 discusses hovering and hovering turns. This document discusses wind compensation during hovering and states in part:

Pilots direct the thrust of the rotor system by using the cyclic to change the tip-path plane as compared to the visible horizon to induce travel or compensate for the wind and hold a position.

This document discusses how a hovering turn should be conducted and states in part:

A hovering turn is a maneuver performed at hovering altitude in which the nose of the helicopter is rotated either left or right while maintaining position over a reference point on the surface. Hovering turns can also be made around the mast or tail of the aircraft. The maneuver requires the coordination of all flight controls and demands precise control near the surface. A pilot should maintain a constant altitude, rate of turn, and rpm.

This document also states common errors during a hovering turn and states in part:

Failing to maintain position over the reference point.

Wind Conditions Near Buildings

FAA Technical Report FAA/RD-84/25, Evaluating Wind Flow around Buildings on Heliport Placement, addresses the wind's effect on helicopter operations near buildings. This document discusses pilot experience with assessing wind conditions and states in part:

Pilots become knowledgeable of what winds may be expected about a building or heliport facility through familiarity with varying wind conditions.

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