Aircraft Accident/Incident Report

Nimrod, Oregon 97488
Sunday, August 18, 1991 21:30 PDT

NTSB Narrative Summary Released at Completion of Accident

WHILE IN CRUISE FLIGHT THE ENGINE BEGAN RUNNING ROUGH AND ULTIMATELY SEIZED. THE PILOT EXECUTED A FORCED LANDING DURING DARK NIGHT CONDITIONS ONTO ROUGH AND UNEVEN TERRAIN WITHIN A LOGGING CLEARCUT AREA. DURING THE ROLLOUT THE NOSE GEAR WAS SHEARED OFF AND THE AIRCRAFT NOSED OVER TO AN INVERTED POSITION RESULTING IN SUBSTANTIAL DAMAGE. SUBSEQUENT DISASSEMBLY OF THE ENGINE REVEALED A FATIGUE CRACK WHICH GENERATED INTO A FRACTURE OF THE CRANKSHAFT. THE CRACK WAS OBSERVED TO EMANATE FROM THE OIL TUBE PASSAGE HOLE IN THE NUMBER FOUR SHORT CHEEK OF THE CRANKSHAFT.

NTSB Probable Cause Narrative

THE FRACTURED CRANKSHAFT RESULTING IN ENGINE SEIZURE FOLLOWED BY A FORCED LANDING ON ROUGH AND UNEVEN TERRAIN RESULTING IN SEPARATION OF THE NOSE GEAR.

Event Information

Type of Event Accident
Event Date 8/18/1991
Event Day of the Week Sunday
Time of Event 2130
Event Time Zone Pacific Daylight Time
Event City NIMROD
Event State OREGON
Event Country --
Zipcode of the event site 97488
Event Date Year 1991
Event Date Month 8
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 0
Degrees magnetic from airport 0
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 2054 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 252
Weather Observation Facility ID EUG
Elevation of weather observation facility 365
Distance of event from weather observation facility (units?) 34
Time Zone of the weather observation PDT
Lighting Conditions Night/Dark
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) -18
Dew Point at event time (in degress fahrenheit) -18
Wind Direction (degrees magnetic) 260
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) 0
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) 554
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 44467
Date of most recent change to record Dec 18 2002 11:28AM
User who most recently changed record NTSB\GIUV
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N35831
NTSB Number SEA91LA212
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CESSNA
Aircraft Model U206F
Aircraft Series Identifier U206F
Aircraft Serial Number U20602744
Certified Max Gross Weight 3600
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 6
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection May 2 1991 12:00AM
Airframe hours since last inspection 19
Airframe Hours 3116
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name EVERGREEN HELICOPTERS
Aircraft Owner Street Address 3850 THREE MILE LANE
Aircraft Owner City MCMINNVILLE
Aircraft Owner State OR
Aircraft Owner Country
Aircraft Owner Zipcode 87128
Operator is an individual? --
Operator Name EVERGREEN HELICOPTERS
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 3850 THREE MILE LANE
Operator City MCMINNVILLE
Operator State OR
Operator Country
Operator Zip code 87128
Operator Code LCFA
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 --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code 5S2
Departure City CRESCENT LAKE
Departure State OR
Departure Country
Departure Time 2100
Departure Time Zone PDT
Destination Same as Local Flt --
Destination Airport Code MMV
Destination City MCMINNVILLE
Destination State OR
Destination Country
Specific Phase of Flight Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
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 --