Location: Delta Junction, Alaska
Accident Number: ANC17CA041
Date & Time: August 3, 2017
Registration: N351SH
Aircraft: Airbus AS350
Aircraft Damage: Substantial
Defining Event: Collision during takeoff/land
Injuries: 2 None
Flight Conducted Under: Part 135: Air taxi & commuter - Non-scheduled
Analysis
The helicopter pilot reported that he was transporting a passenger to a remote drilling site where a tracked drilling unit was stationed. He reported that he landed into the wind, which necessitated descending over bordering trees into the drilling site. The helicopter touched down on the dirt, and upon lowering the collective, he reported that he heard a "bang," and the helicopter slowly started to "pick up a ground wobble." The pilot shut down the helicopter, and both occupants exited without further incident.
A postaccident inspection revealed that the blue and red main rotor blades sustained substantial damage from impacting a black 1.5-inch steel frame attached to the tracked drilling unit, which is used to mount a canvas weather shelter for the drilling crews. The pilot reported that the steel frame was not visible to him from above as he was descending into the drilling site. The pilot further reported that he had made multiple landings at the drilling site in the past 3 months and that, with the previous landings, he had
landed farther past the tracked drilling unit, and the steel frame was always behind the helicopter.
The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
The Federal Aviation Administration Helicopter Flying Handbook (FAA-H-8083-21A, 2012) discusses high and low reconnaissance procedures and states, in part:
The purpose of conducting a high reconnaissance is to determine direction and speed of the wind, a touchdown point, suitability of the landing area, approach and departure axes, and obstacles for both the approach and departure.
A low reconnaissance is accomplished during the approach to the landing area. When flying the approach, verify what was observed in the high reconnaissance, and check for anything new that may have been missed at a higher altitude, such as wires and their supporting structures (poles, towers, etc.), slopes, and small crevices.
Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's failure to maintain clearance from a steel frame attached to a tracked drilling unit. Contributing to the accident was the pilot's failure to visually identify the steel frame during the reconnaissance process.
Findings
Personnel issues Monitoring environment - Pilot
Environmental issues Ground equipment - Effect on operation
Factual Information
History of Flight
Landing Miscellaneous/other
Landing Collision during takeoff/land (Defining event)
Landing Collision with terr/obj (non-CFIT)
Pilot Information
Certificate: Commercial
Age: 64, Male
Airplane Rating(s): None
Seat Occupied: Right
Other Aircraft Rating(s): Helicopter
Restraint Used: 4-point
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: May 12, 2017
Occupational Pilot: Yes
Last Flight Review or Equivalent: May 12, 2017
Flight Time: (Estimated) 14998 hours (Total, all aircraft), 2300 hours (Total, this make and model), 14800 hours (Pilot In Command, all aircraft), 340 hours (Last 90 days, all aircraft), 167 hours (Last 30 days, all aircraft), 5 hours (Last 24 hours, all aircraft)
Aircraft and Owner/Operator Information
Aircraft Make: Airbus
Registration: N351SH
Model/Series: AS350 B3
Aircraft Category: Helicopter
Year of Manufacture: 2008
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 4598
Landing Gear Type: Skid
Seats: 6
Date/Type of Last Inspection: June 19, 2017 100 hour
Certified Max Gross Wt.: 4961 lbs
Time Since Last Inspection:
Engines: 1 Turbo shaft
Airframe Total Time: 3823.7 Hrs as of last inspection
Engine Manufacturer: Safran Helicopter Engines
ELT: C126 installed, not activated
Engine Model/Series: Arriel 2B1
Registered Owner:
Rated Power: 847 Horsepower
Operator:
Operating Certificate(s) Held: Rotorcraft external load (133), On-demand air taxi (135), Agricultural aircraft (137)
Operator Does Business As: SOLOY HELICOPTERS, LLC
Operator Designator Code:
Meteorological Information and Flight Plan
Conditions at Accident Site: Visual (VMC)
Condition of Light: Day
Observation Facility, Elevation: PABI,1277 ft msl
Distance from Accident Site: 35 Nautical Miles
Observation Time: 20:53 Local
Direction from Accident Site: 217°
Lowest Cloud Condition: Few / 6500 ft AGL
Visibility: 10 miles
Lowest Ceiling: Broken / 11000 ft AGL
Visibility (RVR):
Wind Speed/Gusts: 13 knots /
Turbulence Type Forecast/Actual: / None
Wind Direction: 180°
Turbulence Severity Forecast/Actual: / N/A
Altimeter Setting: 30.12 inches Hg
Temperature/Dew Point: 22°C / 8°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: DELTA JUNCTION, AK (76AK)
Type of Flight Plan Filed: Company VFR
Destination: DELTA JUNCTION, AK (76AK)
Type of Clearance: None
Departure Time:
Type of Airspace: Class G
Wreckage and Impact Information
Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: 1 None
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 None
Latitude, Longitude: 64.467781,-144.914993(est)