Status:	Final
Date:	12 MAR 1985
Time:	00:15 AST
Type:	de Havilland Canada DHC-6 Twin Otter 300
Operator:	Seair Alaska Airlines
Registration:	N540N
C/n / msn:	401
First flight:	1973
Total airframe hrs:	13652
Engines:	2 Pratt & Whitney Canada PT6A-27
Crew:	Fatalities: 0 / Occupants: 2
Passengers:	Fatalities: 0 / Occupants: 2
Total:	Fatalities: 0 / Occupants: 4
Airplane damage:	Substantial
Airplane fate:	Written off (damaged beyond repair)
Location:	Barter Island, AK (United States of America)
Phase:	Approach (APR)
Nature:	Domestic Non Scheduled Passenger
Departure airport:	Prudhoe Bay Airport, AK (PUO), United States of America
Destination airport:	Barter Island Airport, AK (BTI/PABA), United States of America

Narrative:
The aircraft had to carry out a missed approach to a temporary winter landing strip and crashed in a steep nose down attitude, about 900m past the runway end due to ice accretion (3/16 inch) on the wings. The de-ice boots were not used.

PROBABLE CAUSE:
"Flight manuals..not followed..pilot in command
Weather condition..icing conditions
Altitude..inadequate..pilot in command
CONTRIBUTING FACTORS
Terrain condition..snow covered
Overconfidence in aircraft's ability..pilot in command
Inadequate surveillance of operation..company/operator management
Weather condition..fog
Weather evaluation..inaccurate..pilot in command
Company-induced pressure..company/operator management
Inadequate surveillance of operation..FAA
Light condition..dark night
In-flight planning/decision..poor..pilot in command
Expectancy..other person
Insufficient standards/requirements,operation/operator..company/operator management
Light condition..dark night
Weather evaluation..inaccurate..pilot in command
Fatigue (flight and ground schedule)..pilot in command
Flight into known adverse weather..intentional..pilot in command
Wing..ice
Anti-ice/deice system..not used..pilot in command"

Sources:
» NTSB id ANC85FA054