Aviation Accident Summaries

Aviation Accident Summary ANC17LA040

Solomon, AK, USA

Aircraft #1

N4138M

ROBINSON HELICOPTER COMPANY R44

Analysis

The pilot was conducting a commercial charter flight for the passenger to place mineral claim markers. He stated that, while flying over a lagoon at an altitude lower than he "should have been," while making inputs to the GPS unit, he likely inadvertently applied forward cyclic and allowed the helicopter to descend into the water below. The pilot reported that there were no mechanical malfunctions or anomalies with the helicopter that would have precluded normal operation. Although helicopters operated under 14 CFR Part 135 are required to be equipped with radar altimeters, the accident helicopter was not, as the operator had been authorized by the Federal Aviation Administration (FAA) to operate the helicopter without one. It is likely that if a radar altimeter was installed in the helicopter at the time of the accident, was functioning properly, and was set to provide an aural warning at a predetermined altitude, the pilot may have had adequate time to recognize and stop the inadvertent descent before impact with water.

Factual Information

On August 3, 2017, about 1032 Alaska daylight time, a Robinson Helicopter Company R-44 helicopter, N4138M, was substantially damaged when it was involved in an accident near Solomon, Alaska. The commercial pilot and passenger were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations (CFR) Part 135 on-demand charter flight. The pilot reported that the purpose of the flight was to place mineral claim markers, which involved maneuvering the helicopter over a designated GPS location, after which the passenger would drop the marker from the rear left seat of the helicopter. Some of the mineral claim corners were in water, and the placement of those markers had to be offset to the nearest land mass. The pilot departed Nome Airport (OME), Nome, Alaska, and flew to the passenger's residence about 4 miles east, where the passenger boarded the helicopter and they departed on the accident flight. After reaching the destination and while placing the markers, helicopter was operating about 10 to 15 ft above the water over a lagoon between the mainland and a sand barrier. The pilot reported that he was "lower than he should have been" and lost situational awareness while programming the GPS. He inadvertently allowed the helicopter to descend into the water "in a more level or slight nose-low attitude." He further reported that he must have pushed forward on the cyclic as he leaned forward to manipulate the GPS. Upon impact, the helicopter rolled and came to rest on its right side in about 4 ft of water. After egressing, the pilot and passenger waded about 200 ft to the shore with the helicopter occupant survival bag and a satellite telephone. The pilot contacted the operator with the satellite telephone and a second company helicopter was dispatched to pick up the pilot and passenger about 1200. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation and stated that the accident could have been prevented by maintaining a higher altitude and not fixating on the GPS unit. The helicopter sustained substantial damage to the main rotor system, the fuselage, the tail boom, and the tail rotor system.

Probable Cause and Findings

The pilot's failure to maintain adequate altitude above water, and his loss of situational awareness, which resulted in an inadvertent descent and collision with water.

 

Source: NTSB Aviation Accident Database

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