History of Flight
On April 19, 2018, at about 1600 Alaska daylight time, a Robinson R44 Raven II helicopter equipped with tundra/snow boards, registration N511CC, was conducting a hover turn at Chena Marina Airport (AK28) in Fairbanks, Alaska. The helicopter was parked on an unmarked asphalt pad surrounded by gravel, connected to a private hangar. The private pilot, the sole occupant, had lifted off from the pad with the intention of flying to a remote cabin. Before beginning the hover, the pilot received ATIS information from Fairbanks International Airport (FAI). The pilot, seated in the right seat, brought the helicopter to a hover at about 10 feet above ground level. While executing a hovering turn to the south to face east, a gust of wind from the northeast pushed the helicopter into trees. The main rotor blades struck various spruce and birch trees, and the helicopter subsequently impacted a snowbank near the trees and the ground. The pilot egressed without further incident. Two FAA aviation safety inspectors from the Fairbanks Flight Standards District Office responded on the day of the accident to interview the pilot, photograph the wreckage, and measure the pad and surrounding area. The pad measured 10 feet wide by 45 feet long. The distance from the center of the pad to the snowbank was about 40 feet, and to the trees about 44 feet. The pilot reported no preimpact mechanical failures or malfunctions.
Aircraft Information
The helicopter was a Robinson R44 Raven II. According to the Pilot's Operating Handbook (POH), the main rotor system has a radius of 16.5 feet and a diameter of 33 feet. The length from the front of the fuselage to the end of the tail rotor guard is 29.41 feet.
Meteorological Information
ATIS information Romeo from FAI at 1553 reported wind from 330° at 11 knots. ATIS Sierra at 1653 reported wind from 340° at 12 knots. No wind gusts were reported in the ATIS information. FAI is about 1 mile east of AK28 at an elevation of 439 feet above mean sea level.
Wreckage and Impact Information
The helicopter sustained substantial damage to the main rotor system, fuselage, tail boom, and tail rotor system.
Additional Information
The FAA Helicopter Flying Handbook (FAA-H-8083-21) discusses hovering turns, noting that pilots direct rotor system thrust using the cyclic to compensate for wind. Common errors include failing to maintain position over a reference point. FAA Technical Report FAA/RD-84/25 addresses wind flow around buildings and heliport placement, stating that pilots become knowledgeable about expected winds through familiarity with varying conditions.