Aircraft Accident/Incident Report

Fort Yukon, Alaska 99740
Friday, January 13, 1989 17:12 AST

NTSB Narrative Summary Released at Completion of Accident

DURING CRUISE FLIGHT AT 8000 FEET ABOVE MEAN SEA LEVEL THE CO-PILOT NOTICED A 100 POUND TORQUE INCREASE ON THE NUMBER TWO ENGINE. DURING HIS ATTEMPT TO REDUCE THE TORQUE HE HEARD AN EXPLOSION, SAW SPARKS COME FROM THE NUMBER TWO ENGINE EXHAUST STACKS AND OBSERVED A SLOW TURNING PROPELLER AS THE ENTIRE ENGINE NACELLE DISAPPEARED BENEATH THE AIRPLANE. FULL POWER ON THE NUMBER ONE ENGINE ALLOWED THE CREW TO REDUCE THE RATE OF DESCENT TO 1,500 FOOT PER MINUTE AND THEY CRASH LANDED ON THE FROZEN RIVER. ON SITE EXAMINATION REVEALED ONE PROPELLER BLADE FROM THE NUMBER TWO ENGINE WAS MISSING AND THAT THE NUMBER TWO ENGINE HAD SEPARATED DURING THE IMPACT SEQUENCE. SUBSEQUENT METALLURGICAL EXAMINATION SHOWED A FATIGUE FRACTURE ON THE REMAINING STUB OF THE MISSING BLADE.

NTSB Probable Cause Narrative

THE SEPARATION OF A SINGLE PROPELLER BLADE WHICH CAUSED THE DOWNWARD AND REARWARD DISPLACEMENT OF THE NUMBER TWO ENGINE.

Event Information

Type of Event Accident
Event Date 1/13/1989
Event Day of the Week Friday
Time of Event 1712
Event Time Zone Atlantic Standard Time
Event City FORT YUKON
Event State ALASKA
Event Country --
Zipcode of the event site 99740
Event Date Year 1989
Event Date Month 1
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 17
Degrees magnetic from airport 50
Airport Elevation 0
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1650 Atlantic Standard Time
Direction of event from weather observation facility (degrees) 240
Weather Observation Facility ID FYU
Elevation of weather observation facility 433
Distance of event from weather observation facility (units?) 17
Time Zone of the weather observation AST
Lighting Conditions Night/Bright
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) 15
Air Temperature at event time (in degrees celsius) 4
Dew Point at event time (in degress fahrenheit) 9
Wind Direction (degrees magnetic) 30
Variable Wind Indicator Unknown
Wind Speed (knots) 3
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 17
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 6026
NTSB Notification Source --
NTSB Notification Date Jan 13 1989 12:00AM
NTSB Notification Time 1730
Fiche Number and/or location -used to find docket information 38759
Date of most recent change to record Dec 13 2000 12:24PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number CFBCH
NTSB Number ANC89FA034
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 129: Foreign
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BEECH
Aircraft Model BE-99
Aircraft Series Identifier BE-99
Aircraft Serial Number U162
Certified Max Gross Weight 11500
Aircraft Category Airplane
Aircraft Registration Class Foreign Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 19
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Dec 10 1988 12:00AM
Airframe hours since last inspection 50
Airframe Hours 20967
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site Yes
ELT Type --
Aircraft Owner Name AKLAK AIR LTD
Aircraft Owner Street Address BOX 1190
Aircraft Owner City INUVIK
Aircraft Owner State CD
Aircraft Owner Country
Aircraft Owner Zipcode
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate Yes - certificate holder
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 Non-scheduled
Indicates Domestic or International Flight International
Operator carrying Pax/Cargo/Mail Passenger/Cargo
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code
Departure City INUVIK
Departure State CD
Departure Country
Departure Time 1547
Departure Time Zone AST
Destination Same as Local Flt --
Destination Airport Code FAI
Destination City FAIRBANKS
Destination State AK
Destination Country
Specific Phase of Flight Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --