Pilot Heard A Loud "Bang" -- Followed By The Low Rotor RPM

Location: Hillsboro, OR Accident Number: WPR20LA119
Date & Time: 04/06/2020, 1410 PDT Registration: N725GT
Aircraft: Robinson R44 Injuries: 1 None

On April 6, 2020, about 1410 Pacific daylight time, a Robinson R44 Raven II helicopter, N725GT, was substantially damaged following a forced landing at Portland-Hillsboro Airport (HIO), Portland, Oregon.

The pilot was not injured. The helicopter was registered to and operated by the Horizons Unlimited Air Inc. as a Title 14 Code of Federal Regulations Part 91 flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight destined for Warren, Oregon.

The pilot reported that, during takeoff, about 30 to 40 ft above ground level, he heard a loud "bang", followed by the low rotor RPM. In response, he lowered the collective and performed an autorotation on the paved taxiway. As a result of the hard impact, the skids spread, and the tailboom received substantial damage.

Initial examination of the engine revealed that the fuel servo induction air inlet duct was partially collapsed. The inner rubberized fabric liner of the duct had partially delaminated and separated from the outer rubberized fabric, obstructing the interior volume of the duct. The duct was retained, and the helicopter was secured for further examination.

FMI: www.ntsb.gov