Aircraft Accident/Incident Report

Lowell, Idaho 83539
Sunday, May 23, 1993 11:15 PDT

NTSB Narrative Summary Released at Completion of Accident

WHILE FLYING AT 8000 FEET MSL A PARTIAL POWER LOSS DEVELOPED. WHEN THE PILOT OBSERVED OIL ON THE LEFT WING STRUT HE CHOSE TO EXECUTE A PRECAUTIONARY LANDING IN A FIELD TO PREVENT ENGINE SEIZURE. DURING THE LANDING ROLL, IN SOFT TERRAIN, THE AIRCRAFT NOSED OVER. POST CRASH EXAMINATION REVEALED THE NUMBER TWO CYLINDER EXHAUST ROCKER ARM BROKEN IN HALF. METALLURGICAL EXAMINATION REVEALED THAT THE ROCKER ARM SEPARATED IN FATIGUE. THE ROCKER ARM(S), WHICH WERE NOT UNDER AN APPROVED STC, HAD BEEN INSTALLED APPROXIMATELY 11 HOURS PREVIOUS TO THE ACCIDENT.

NTSB Probable Cause Narrative

FATIGUE OF THE ROCKER ARM AND UNSUITABLE TERRAIN WHICH WAS ENCOUNTERED DURING THE PRECAUTIONARY LANDING.

Event Information

Type of Event Accident
Event Date 5/23/1993
Event Day of the Week Sunday
Time of Event 1115
Event Time Zone Pacific Daylight Time
Event City LOWELL
Event State IDAHO
Event Country --
Zipcode of the event site 83539
Event Date Year 1993
Event Date Month 5
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 1051 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 67
Weather Observation Facility ID MSO
Elevation of weather observation facility 3201
Distance of event from weather observation facility (units?) 27
Time Zone of the weather observation MDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 7000
Sky/Lowest/Cloud Conditions Scattered
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) 16
Dew Point at event time (in degress fahrenheit) 3
Wind Direction (degrees magnetic) 50
Variable Wind Indicator Unknown
Wind Speed (knots) 8
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
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 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1488
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 945
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 11 2000 1:20PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4080Y
NTSB Number SEA93LA120
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 185A
Aircraft Series Identifier 185A
Aircraft Serial Number 1850280
Certified Max Gross Weight 3200
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 Annual
Date of Last Inspection May 15 1993 12:00AM
Airframe hours since last inspection 11
Airframe Hours --
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name FORBES, CLARENCE R.
Aircraft Owner Street Address 124 JUNIPER WAY
Aircraft Owner City STEVENSVILLE
Aircraft Owner State MT
Aircraft Owner Country
Aircraft Owner Zipcode 59870
Operator is an individual? --
Operator Name FORBES, CLARENCE, R.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 124 JUNIPER WAY
Operator City STEVENSVILLE
Operator State MT
Operator Country
Operator Zip code 59870
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 --
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 32S
Departure City STEVENSVILLE
Departure State MT
Departure Country
Departure Time 1000
Departure Time Zone MDT
Destination Same as Local Flt crash at destination city
Destination Airport Code 32S
Destination City
Destination State
Destination Country
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
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 --