ASN logo
ASN Wikibase Occurrence # 187047
Last updated: 20 October 2018
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:06-MAY-2016
Time:19:00
Type:Silhouette image of generic AS50 model; specific model in this crash may look slightly different
Aérospatiale AS 350B2 AStar
Owner/operator:Temsco Helicopters, Inc.
Registration: N94TH
C/n / msn: 2548
Fatalities:Fatalities: 1 / Occupants: 1
Other fatalities:0
Aircraft damage: Substantial
Category:Accident
Location:Denver Glacier, near Skagway, AK -   United States of America
Phase: En route
Nature:OWRK
Departure airport:Skagway, AK
Destination airport:Skagway, AK
Investigating agency: NTSB
Narrative:
The non-instrument-rated commercial pilot was making a visual flight rules internal-cargo company flight in the helicopter. He was returning to base in the helicopter after dropping off 1 employee and 12 dogs at a remote dog camp situated on a glacier surrounded by mountainous terrain. The pilot had previously completed 5 of the day's 7 planned roundtrip flights from the base to the dog camp. According to the dog camp manager, the weather was deteriorating with snow and wind increasing when the pilot departed on the accident flight. The dog camp manager's observations and radar data indicated that the pilot attempted to depart via the normal route to the south but turned around. He likely encountered low visibility conditions and then attempted several departures by routes to the north of the dog camp. About 8 minutes after departure, the helicopter impacted snow-covered mountainous terrain about 2 miles northeast of the dog camp.

Postaccident examination of the helicopter revealed no evidence of preimpact mechanical anomalies that would have precluded normal operation. Given the deteriorating weather conditions when the pilot departed, it is likely that the pilot continued visual flight into an area of instrument meteorological conditions, which resulted in the pilot experiencing a loss of visual reference and subsequent controlled flight into terrain.

During the impact sequence, the two cargo straps used to secure two wooden dog boxes to the rear cabin floor failed, and the dog boxes shifted forward, striking the back of the pilot's fiberglass seat. It could not be determined if the forward movement of the dog boxes during the accident sequence contributed to the injuries sustained by the pilot.

Immediately before departing from the dog camp on the accident flight, the pilot told the dog camp manager that, due to the degrading weather conditions, he would not be coming back for the last scheduled trip of the day, and the dog camp manager told the pilot that he agreed with him. However, the pilot then told the dog camp manager, "but don't give up on me yet," a statement consistent with self-induced pressure to complete the day's series of flights.

On one of the day's previous flights, the pilot reported to the base manager, who was exercising operational control at the time of the accident, that he had encountered icing conditions while in flight. The base manager told the pilot "to do what he thought was best." However, flight operations in icing conditions are prohibited by the helicopter's rotorcraft flight manual and the operator's operations manual, and the pilot's statement should have prompted the base manager to suspend the flights. If flight operations had been cancelled for the day when the pilot reported the icing conditions, the subsequent flights, including the accident flight, would not have occurred. The base manager's failure to appropriately exercise operational control and terminate the flights may have been due to the difference in experience between the base manager, who had been operating these flights for 8 years, and the pilot, who had been operating these flights for 25 years.

Probable Cause: The pilot's decision to continue visual flight into an area of instrument meteorological conditions, which resulted in the pilot experiencing a loss of visual reference and subsequent controlled flight into terrain. Contributing to the accident were the pilot's self-induced pressure to complete the flight and the operator's failure to maintain operational control over the flight.

Sources:

NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20160507X31120&key=1
FAA register: FAA register: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=N94TH

Accident investigation:
cover
  
Investigating agency: NTSB
Status: Investigation completed
Duration: 2 years and 5 months
Download report: Final report


Images:


Photos: NTSB

Revision history:

Date/timeContributorUpdates
07-May-2016 22:50 Geno Added
08-May-2016 09:48 CTYONE Updated [Aircraft type, Source]
08-May-2016 13:48 Aerossurance Updated [Time, Aircraft type, Nature, Source, Narrative]
09-May-2016 22:02 Geno Updated [Aircraft type, Registration, Cn, Nature, Source, Narrative]
10-May-2016 11:11 Aerossurance Updated [Time, Aircraft type]
10-May-2016 11:13 Aerossurance Updated [Time]
20-May-2016 06:11 Aerossurance Updated [Time, Phase, Source, Damage, Narrative]
21-Dec-2016 19:30 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
08-Oct-2018 16:43 ASN Update Bot Updated [Time, Operator, Nature, Departure airport, Destination airport, Source, Narrative, Accident report, ]
08-Oct-2018 17:33 harro Updated [Nature, Departure airport, Source, Narrative, Photo]
13-Oct-2018 12:06 Aerossurance Updated [Time, Operator, Location, Departure airport, Source]
15-Oct-2018 17:05 ASN Update Bot Updated [Time, Operator, Nature, Departure airport, Source, Narrative, Accident report, ]

Corrections or additions? ... Edit this accident description