Aircraft Accident/Incident Report

Nightmute, Alaska 99690
Wednesday, April 8, 1998 16:55 AKD

NTSB Narrative Summary Released at Completion of Accident

The commercial pilot departed on a CFR Part 135/government flight for a remote coastal village to pick up the sole passenger. Just before landing at the village, light snow began to fall, and the wind conditions increased to about 20 knots. There was no evidence the pilot obtained a weather briefing. The area forecast included isolated ceilings below 1,000 feet, and visibilities below 3 miles in blowing snow and mist from offshore. The forecast wind conditions included 20 knots to 40 knots from offshore. Airmets were issued for moderate low level turbulence, mountain obscuration, strong surface winds along the coast, and moderate rime icing in clouds. When the airplane departed the village on the accident flight, a resident said the visibility was 1/4 to 1/2 mile in blowing snow. The flight did not reach the destination. The wreckage was located 8 miles away in snow covered terrain after two days of blizzard conditions. The airplane collided with the ground in a near vertical attitude, and exhibited high speed destruction. An examination of the engine did not reveal any preimpact malfunction. Evidence of engine combustion, heat, and rotation were noted during the engine examination.

NTSB Probable Cause Narrative

The pilot's continued VFR flight into instrument meteorological conditions which resulted in spatial disorientation and subsequent loss of aircraft control. Factors in the accident were meteorological conditions consisting of low ceilings, and blowing snow, and the pilot's failure to obtain a preflight weather briefing.

Event Information

Type of Event Accident
Event Date 4/8/1998
Event Day of the Week Wednesday
Time of Event 1655
Event Time Zone --
Event City NIGHTMUTE
Event State ALASKA
Event Country --
Zipcode of the event site 99690
Event Date Year 1998
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1537 Atlantic Daylight Time
Direction of event from weather observation facility (degrees) 243
Weather Observation Facility ID PAM
Elevation of weather observation facility 48
Distance of event from weather observation facility (units?) 43
Time Zone of the weather observation ADT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 1.34
Air Temperature at event time (in degrees celsius) 2
Dew Point at event time (in degress fahrenheit) -2
Wind Direction (degrees magnetic) 170
Variable Wind Indicator Unknown
Wind Speed (knots) 24
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 2
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 459
NTSB Notification Source --
NTSB Notification Date Apr 8 1998 12:00AM
NTSB Notification Time 2348
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 11:04AM
User who most recently changed record dbo
Basic weather conditions Instrument Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N5485R
NTSB Number ANC98GA036
Missing Aircraft Indicator N
Federal Aviation Reg. Part Public Use
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Cessna
Aircraft Model 185F
Aircraft Series Identifier 185F
Aircraft Serial Number 18503038
Certified Max Gross Weight 3350
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Mar 27 1998 12:00AM
Airframe hours since last inspection --
Airframe Hours 6126
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name Y-K AVIATION INC.
Aircraft Owner Street Address P.O. BOX 1628
Aircraft Owner City BETHEL
Aircraft Owner State AK
Aircraft Owner Country
Aircraft Owner Zipcode 99559
Operator is an individual? --
Operator Name ALASKA NATIVE HEALTH SERVICE
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 4141 AMBASSADOR DR.
Operator City ANCHORAGE
Operator State AK
Operator Country
Operator Zip code 99508
Operator Code
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code OOK
Departure City TOKSOOK BAY
Departure State AK
Departure Country
Departure Time 1650
Departure Time Zone ADT
Destination Same as Local Flt --
Destination Airport Code BET
Destination City BETHEL
Destination State AK
Destination Country
Specific Phase of Flight Unknown
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Oct 22 2001 3:26PM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --