Unknown or Undetermined: Hughes 369D, N501VS; accident occurred February 19, 2018 in Marshall Islands

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Los Angeles, California

Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf 

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

http://registry.faa.gov/N501VS


Location: Marshall Islands, MH
Accident Number: WPR18CA100
Date & Time: 02/19/2018, 1055 LCL
Registration: N501VS
Aircraft: HUGHES 369D
Aircraft Damage: Substantial
Defining Event: Unknown or undetermined
Injuries: 2 Minor
Flight Conducted Under: Part 91: General Aviation - Aerial Observation - Sightseeing 

The pilot and passenger departed on a fish survey flight over the open ocean. About an hour into the flight, a descent was made to sea level to attach a GPS buoy on a log. After attaching the buoy, the helicopter was climbing through 400-500 ft, when the pilot heard a bang come from the area of the rotor head, followed by a shake in the cyclic control. The pilot radioed the support vessel notifying them of the issue and proceeded to head in their direction. The pilot continued to experience intermittent flight control problems, and unable to reach the vessel, attempted to deploy the inflatable floats, however they did not deploy. The pilot subsequently declared a mayday and initiated a forced water landing. After the helicopter impacted the water, it rolled inverted. The pilot and passenger egressed before the helicopter sank.

The helicopter was not recovered.

Pilot Information

Certificate: Commercial
Age: 26, Male
Airplane Rating(s): None
Seat Occupied: Left
Other Aircraft Rating(s): Helicopter
Restraint Used:
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 With Waivers/Limitations
Last FAA Medical Exam: 07/03/2016
Occupational Pilot: Yes
Last Flight Review or Equivalent:
Flight Time:

Aircraft and Owner/Operator Information

Aircraft Make: HUGHES
Registration: N501VS
Model/Series: 369D D
Aircraft Category: Helicopter
Year of Manufacture: 1977
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 170050D
Landing Gear Type: Emergency Float; Skid
Seats: 
Date/Type of Last Inspection: 12/19/2017, 100 Hour
Certified Max Gross Wt.:
Time Since Last Inspection: 79 Hours
Engines:  Turbo Shaft
Airframe Total Time: 18502.5 Hours as of last inspection
Engine Manufacturer: Rolls Royce
ELT:
Engine Model/Series: 250-C20B
Registered Owner: On file
Rated Power: 420 hp
Operator: On file
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation:
Distance from Accident Site: 
Observation Time:
Direction from Accident Site:
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 10 knots /
Turbulence Type Forecast/Actual:
Wind Direction: 270°
Turbulence Severity Forecast/Actual:
Altimeter Setting:
Temperature/Dew Point: 31°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Marshall Island, MH
Type of Flight Plan Filed: None
Destination: Marshall Islands, MH
Type of Clearance: None
Departure Time: 1000 LCL
Type of Airspace:

Wreckage and Impact Information

Crew Injuries: 2 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 Minor
Latitude, Longitude: 34.980000, 159.980000 (est)