Aircraft Accident/Incident Report

Somerton, Arizona 85350
Thursday, November 15, 1990 20:30 MST

NTSB Narrative Summary Released at Completion of Accident

THE PILOT EXPERIENCED A LOSS OF ENGINE POWER AND COLLIDED WITH THE TERRAIN DURING A SWATH RUN. EXAMINATION OF THE ENGINE REVEALED THE NUMBER 3 EXHAUST VALVE WAS CRACKED. THE ENGINE HAD 266 HOURS SINCE OVERHAUL AND HAD 20 HOURS SINCE THE LAST INSPECTION.

NTSB Probable Cause Narrative

THE FAILURE OF THE NUMBER 3 EXHAUST VALVE WHICH LED TO AN ENGINE FAILURE AND SUBSEQUENT CRASH LANDING.

Event Information

Type of Event Accident
Event Date 11/15/1990
Event Day of the Week Thursday
Time of Event 2030
Event Time Zone Mountain Standard Time
Event City SOMERTON
Event State ARIZONA
Event Country --
Zipcode of the event site 85350
Event Date Year 1990
Event Date Month 11
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 0
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
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) 0
Air Temperature at event time (in degrees celsius) 21
Dew Point at event time (in degress fahrenheit) -1
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Calm
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 FAA
NTSB Docket Number (internal use) 1862
NTSB Notification Source --
NTSB Notification Date Nov 16 1990 12:00AM
NTSB Notification Time 745
Fiche Number and/or location -used to find docket information 43759
Date of most recent change to record Dec 12 2000 5:33PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4441S
NTSB Number LAX91DUJ03
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Air Tractor
Aircraft Model AT-302
Aircraft Series Identifier AT-302
Aircraft Serial Number 302-0101
Certified Max Gross Weight 5000
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Mar 1 1990 12:00AM
Airframe hours since last inspection 20
Airframe Hours 4950
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name JEFFREY L KOTTENBROOK
Aircraft Owner Street Address RT, 1 BOX 9M
Aircraft Owner City SOMERTON
Aircraft Owner State AZ
Aircraft Owner Country
Aircraft Owner Zipcode 85350
Operator is an individual? --
Operator Name KOTTENBROOK, JEFFREY L.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address ROUTE 1, BOX 9M
Operator City SOMERTON
Operator State AZ
Operator Country
Operator Zip code 85350
Operator Code ZCKG
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Agriculture
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) Aerial Application
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 2015
Departure Time Zone MST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Maneuvering
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 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --