Thursday, May 09, 2019

Aerospatiale AS350 B2 Ecureuil, N288CH: Accident occurred April 27, 2019 in Juneau, Alaska -and- Accident occurred May 18, 2018 in Yakutat, Alaska

View of tail-boom damage 



Aviation Accident Final Report - National Transportation Safety Board

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Juneau, Alaska

Investigation Docket - National Transportation Safety Board:


Location: Juneau, AK
Accident Number: GAA19CA233
Date & Time: 04/27/2019, 1737 AKD
Registration: N288CH
Aircraft: AEROSPATIALE AS350
Aircraft Damage: Substantial
Defining Event: Miscellaneous/other
Injuries: 6 None
Flight Conducted Under: Part 135: Air Taxi & Commuter - Non-scheduled 

Analysis

The pilot reported that, during the second landing on a "ridge" and while dropping off passengers for skiing, the helicopter's tail rotor contacted a higher area of snow-covered terrain.  

The helicopter sustained substantial damage to the tailboom and the tail rotor gear box's mounting surface.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. 

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 a proper approach to landing on a ridge and his failure to maintain clearance from snow-covered terrain, which resulted in a tail rotor strike.

Findings

Aircraft Descent/approach/glide path - Not attained/maintained
Personnel issues Task monitoring/vigilance - Pilot
Environmental issues Snow/slush/ice covered surface - Effect on operation

Factual Information

History of Flight

Landing Miscellaneous/other (Defining event)
Landing Collision with terr/obj (non-CFIT)


Pilot Information

Certificate: Flight Instructor; Commercial
Age: 40, Male
Airplane Rating(s): None
Seat Occupied: Right
Other Aircraft Rating(s): Helicopter
Restraint Used: 4-point
Instrument Rating(s): Helicopter
Second Pilot Present: No
Instructor Rating(s): Helicopter; Instrument Helicopter
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 02/06/2019
Occupational Pilot: Yes
Last Flight Review or Equivalent: 04/02/2019
Flight Time:  (Estimated) 3707 hours (Total, all aircraft), 1384 hours (Total, this make and model), 3650 hours (Pilot In Command, all aircraft), 91 hours (Last 90 days, all aircraft), 37 hours (Last 30 days, all aircraft), 3 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: AEROSPATIALE
Registration: N288CH
Model/Series: AS350 B2
Aircraft Category: Helicopter
Year of Manufacture: 1990
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 2383
Landing Gear Type: High Skid
Seats: 7
Date/Type of Last Inspection: 03/05/2019, 100 Hour
Certified Max Gross Wt.: 4961 lbs
Time Since Last Inspection:
Engines: 1 Turbo Shaft
Airframe Total Time: 10172.3 Hours at time of accident
Engine Manufacturer: Safran
ELT: C126 installed, not activated
Engine Model/Series: Ariel 1D1
Registered Owner: Coastal Helicopters Inc
Rated Power: 732 hp
Operator: Coastal Helicopters Inc
Operating Certificate(s) Held: Commercial Air Tour (136); Agricultural Aircraft (137); Rotorcraft External Load (133); On-demand Air Taxi (135)
Operator Does Business As:
Operator Designator Code: XCHA 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PAJN, 24 ft msl
Distance from Accident Site: 9 Nautical Miles
Observation Time: 0253 UTC
Direction from Accident Site: 203°
Lowest Cloud Condition: Few / 6000 ft agl
Visibility:  10 Miles
Lowest Ceiling:
Visibility (RVR):
Wind Speed/Gusts: 6 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 250°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.39 inches Hg
Temperature/Dew Point: 14°C / -8°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Juneau, AK (PAJN)
Type of Flight Plan Filed: Company VFR
Destination: Juneau, AK
Type of Clearance: Unknown
Departure Time: 1700 AKD
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries:  None
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries:  None
Latitude, Longitude:  58.491111, -134.455000 (est)

Additional Participating Entity: 
Federal Aviation Administration / Flight Standards District Office; Juneau, Alaska

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

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


Aviation Accident Data Summary - National Transportation Safety Board: https://app.ntsb.gov/pdf 
 


Location: Yakutat, AK
Accident Number: GAA18CA289
Date & Time: 05/18/2018, 1500 AKD
Registration: N288CH
Aircraft: AEROSPATIALE AS350 B2 ECUREUIL
Aircraft Damage: Substantial
Defining Event: Miscellaneous/other
Injuries: 3 None
Flight Conducted Under: Part 135: Air Taxi & Commuter - Non-scheduled

Analysis

The helicopter pilot reported that, during startup on an off-airport landing pad, the helicopter was facing into the wind, and the airspeed indicator was showing gusting wind conditions. As the blades began to turn, he felt a strong wind gust and heard a loud bang almost simultaneously, and the helicopter "lurched" to the right about 5°. He immediately aborted the start procedure and applied the rotor brake.

Postaccident examination revealed that the helicopter's main rotor blade had struck the tail rotor driveshaft cover and damaged the tail rotor drive shaft and support assembly.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.

The pilot reported that the weather at the accident site, about the time of the accident, was wind from 130° at 25 knots, gusting to 30 knots with light, terrain-induced turbulence.

The flight manual stated that the wind envelope for spinning and stopping the rotors has been substantiated for winds of 40 knots from any direction and for 50-knot headwinds. 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The helicopter's movement during startup in gusting wind conditions, which resulted in the main rotor striking the tailboom.

Findings

Aircraft
Performance/control parameters - Attain/maintain not possible (Cause)

Environmental issues
Gusts - Effect on operation

Factual Information

History of Flight

Standing-engine(s) start-up
Miscellaneous/other (Defining event) 

Pilot Information

Certificate: Commercial
Age: 45, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land; Single-engine Sea
Seat Occupied: Right
Other Aircraft Rating(s): Glider; Helicopter
Restraint Used: 4-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 04/03/2018
Occupational Pilot: Yes
Last Flight Review or Equivalent: 05/09/2018
Flight Time:  (Estimated) 4648 hours (Total, all aircraft), 701 hours (Total, this make and model), 4500 hours (Pilot In Command, all aircraft), 55.8 hours (Last 90 days, all aircraft), 47.8 hours (Last 30 days, all aircraft), 2.7 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: AEROSPATIALE
Registration: N288CH
Model/Series: AS350 B2 ECUREUIL NO SERIES
Aircraft Category: Helicopter
Year of Manufacture: 1990
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 2383
Landing Gear Type: Emergency Float; High Skid
Seats: 7
Date/Type of Last Inspection: 02/13/2018, 100 Hour
Certified Max Gross Wt.: 4961 lbs
Time Since Last Inspection:
Engines: 1 Turbo Shaft
Airframe Total Time: 9854.4 Hours at time of accident
Engine Manufacturer: TURBOMECA
ELT: C126 installed, not activated
Engine Model/Series: ARRIEL 1D1
Registered Owner: COASTAL HELICOPTERS INC
Rated Power: 531 hp
Operator: COASTAL HELICOPTERS INC
Operating Certificate(s) Held:  Commercial Air Tour (136); Agricultural Aircraft (137); Rotorcraft External Load (133); On-demand Air Taxi (135)
Operator Does Business As:
Operator Designator Code: XCHA

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PAYA, 31 ft msl
Distance from Accident Site: 52 Nautical Miles
Observation Time: 2351 UTC
Direction from Accident Site: 300°
Lowest Cloud Condition:
Visibility:  10 Miles
Lowest Ceiling: Broken / 1000 ft agl
Visibility (RVR):
Wind Speed/Gusts: 14 knots / 28 knots
Turbulence Type Forecast/Actual: None / Terrain-Induced
Wind Direction: 140°
Turbulence Severity Forecast/Actual: N/A / Light
Altimeter Setting: 30 inches Hg
Temperature/Dew Point: 10°C / 7°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Juneau, AK (JNU)
Type of Flight Plan Filed: Company VFR
Destination: Yakutat, AK
Type of Clearance: VFR
Departure Time: 1251 AKD
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: 2 None
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 3 None
Latitude, Longitude:  59.083333, -138.200278 (est)

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