Aircraft Accident/Incident Report

Oakley, Idaho 83346
Monday, September 30, 2002 16:30 MDT

NTSB Narrative Summary Released at Completion of Accident

During cruise flight, the aircraft began to lose oil pressure, and the propeller rpm stopped responding to the position of the propeller governor control lever. Eventually the engine oil pressure dropped to zero, and the pilot elected to attempt a forced landing on a country road. Although the touchdown was successful, during the landing roll, the aircraft's wings collided with mailboxes mounted on steel poles situated immediately adjacent to the side of the road. It was later determined that both compression rings on the number four piston had failed (fractured), and that a portion of the piston outer wall near the piston dome had eroded away allowing loss of a majority of the engine's oil through the engine exhaust system.

NTSB Probable Cause Narrative

Failure (fracture) of the two number four piston compression rings, leading to the erosion of a section of the piston sidewall, resulting in the exhaustion of the engine's oil supply during cruise flight, followed by a forced landing on a country road. Factors include mail boxes mounted on metal poles immediately adjacent to the side of the road.

Event Information

Type of Event Accident
Event Date 9/30/2002
Event Day of the Week Monday
Time of Event 1630
Event Time Zone Mountain Daylight Time
Event City Oakley
Event State IDAHO
Event Country --
Zipcode of the event site 83346
Event Date Year 2002
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 421442N
Event Location Longitude 1135246W
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 Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 6000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 13
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 12924
NTSB Notification Source FAA Operations Center
NTSB Notification Date Oct 1 2002 12:00AM
NTSB Notification Time 1340
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Apr 15 2003 4:03PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office Boise FAA FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4232H
NTSB Number SEA02LA187
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Mooney
Aircraft Model M20J
Aircraft Series Identifier --
Aircraft Serial Number 24-0671
Certified Max Gross Weight 2740
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 Retractable
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Sep 16 2002 12:00AM
Airframe hours since last inspection 12
Airframe Hours 3971
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name James H. Sharman
Aircraft Owner Street Address On File
Aircraft Owner City Ruidoso
Aircraft Owner State NM
Aircraft Owner Country USA
Aircraft Owner Zipcode 88345
Operator is an individual? No
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 None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
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 GJT
Departure City Grand Junction
Departure State CO
Departure Country USA
Departure Time 1400
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code BOI
Destination City Boise
Destination State ID
Destination Country USA
Specific Phase of Flight Landing - roll
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Dec 2 2002 2:13PM
User who most recently changed record STAM
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --