Aircraft Incident/Accident Report

Oak Shores, California 93446
Saturday, April 27, 2002 17:45 PDT

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NTSB Narrative Summary Released at Completion of Accident
The airplane collided with trees following a loss of engine power. A passenger heard a "roar" through the four-way intercom. The certified flight instructor (CFI) and the student pilot checked the oil pressure and fuel pressure; both were "good." The CFI pointed to the left and directed the student toward a private strip. During or immediately following the left turn, the CFI said, "I've got it." The student looked back at the two passengers, and motioned with his right hand that they were going to land at the strip. The last thing that the passenger remembered was contact with the trees and coming to rest. The airplane cleared a ridge top, but collided with trees about 1/4 mile from the landing strip. The spark plug for cylinder no. 1 sustained mechanical damage and contained metallic debris. The head of the cylinder no. 1 exhaust valve was missing, and the top of the piston exhibited mechanical damage across its entire surface. Metallurgists examined the valve and cylinder. The valve stem was broken and remained in the valve guide. The stem fractured and there were numerous secondary cracks below the fracture surface. The areas around the valve seats were severely damaged. The fracture surface condition was such that the fracture mechanism could not be determined. The secondary cracks were only in a local area where the material was severely battered and deformed. Many of the cracks were slightly curved and/or did not appear to be perpendicular to the outer or inner surface. These types of cracks are most likely to occur where surfaces have overlapped, or are the result of the excessive local strains in the area. There were no material or dimensional abnormalities that would suggest fatigue. The manufacturer issued maintenance instructions describing methods for determining exhaust valve and guide condition. This maintenance function was optional for the operator, and maintenance records indicated that this had not been done. Although the diameter of the exhaust valve stem was slightly below the specified diameter, this would have a small affect on overall stresses. However, a small change in diameter of the valve stem significantly changes the amount of clearance between the exhaust valve stem and the exhaust valve guide. Excessive clearance can lead to exhaust valve sticking, which can lead to overstress fracture. The engine total time was 2,079 hours, and it had not been overhauled since it was new in 1975. The manufacturer recommended overhaul at 2,000 hours or after 12 years of service life. Given the high hours on this engine and the number of years since overhaul, it was likely that the failure was due to exhaust valve sticking.
NTSB Probable Cause Narrative
the number 1 cylinder exhaust valve fractured and separated resulting in a loss of engine power and an off airport forced landing. A finding in the accident was the owner's failure to maintain the engine in accordance with the manufacturer's recommendations.
Event Information
Type of EventAccident 
Event Date4/27/2002 
Event Day of the WeekSaturday 
Time of Event1745 
Event Time ZonePacific Daylight Time 
Event Country-- 
Zipcode of the event site93446 
Event Date Year2002 
Event Date Month
MidAir Collision IndicatorNo 
On Ground Collision occurred ?No 
Event Location Latitude354727N 
Event Location Longitude1205937W 
Event Location Airport-- 
Event Location Nearest Airport ID-- 
Indicates whether the acc/inc occurred off or on an airportOff Airport/Airstrip 
Distance from airport in statute miles-- 
Degrees magnetic from airport-- 
Airport Elevation-- 
Weather Briefing CompletenessNot pertinent 
Investigator's weather sourceWeather Observation Facility 
Time of the weather observation1753 Pacific Daylight Time 
Direction of event from weather observation facility (degrees)95 
Weather Observation Facility IDPRB 
Elevation of weather observation facility836 
Distance of event from weather observation facility (units?)21 
Time Zone of the weather observationPDT 
Lighting ConditionsDay 
Lowest Ceiling Height-- 
Lowest Non-Ceiling Height-- 
Sky/Lowest/Cloud ConditionsClear 
Sky Condition for Lowest CeilingNone 
Visibility Runway Visual Range (Feet)-- 
Visibility Runway Visual Value (Statute Miles)-- 
Visibility (Statute Miles) 10 
Air Temperature at event time (in degrees celsius)12 
Dew Point at event time (in degress fahrenheit)
Wind Direction (degrees magnetic)-- 
Variable Wind IndicatorVariable 
Wind Speed (knots)
Wind Velocity Indicator -- 
Wind Gust IndicatorNot Gusting 
Wind Gust (knots) -- 
Altimeter Setting at event time (in. Hg) 30.01 
Density Altitude (feet)-- 
Intensity of Precipitation-- 
METAR weather report -- 
Event Highest InjuryFatal 
On Ground, Fatal Injuries-- 
On Ground, Minor Injuries-- 
On Ground, Serious Injuries-- 
Injury Total Fatal
Injury Total Minor-- 
Injury Total None-- 
Injury Total Serious
Injury Total All
Investigating AgencyNTSB 
NTSB Docket Number (internal use)16304 
NTSB Notification SourceFAA  
NTSB Notification DateApr 28 2002 12:00AM 
NTSB Notification Time720 
Fiche Number and/or location -used to find docket informationDMS 
Date of most recent change to recordSep 29 2004 1:02PM 
User who most recently changed recordNTSB\MONR  
Basic weather conditionsVisual Meteorological Cond 
FAA District OfficeWP-SJC-FSDO 
Aircraft Involved
Aircraft #1
Aircraft Registration NumberN9180S 
NTSB NumberLAX02FA148 
Missing Aircraft Indicator-- 
Federal Aviation Reg. PartPart 91: General Aviation 
Type of Flight Plan filedNone 
Flight plan Was Activated?No 
Aircraft FireNone 
Aircraft ExplosionNone 
Aircraft Manufacturer's Full NameBeech 
Aircraft ModelC23 
Aircraft Series Identifier-- 
Aircraft Serial NumberM-1801 
Certified Max Gross Weight2450 
Aircraft CategoryAirplane 
Aircraft Registration ClassU.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
Number of Engines
Fixed gear or retractable gearFixed 
Aircraft, Type of Last InspectionAnnual 
Date of Last InspectionApr 6 2001 12:00AM 
Airframe hours since last inspection118 
Airframe Hours2097 
ELT InstalledYes 
ELT ActivatedYes 
ELT Aided Location of Event SiteYes 
ELT Type-- 
Aircraft Owner NameStephen W. Meester 
Aircraft Owner Street AddressOn File 
Aircraft Owner CityOakdale 
Aircraft Owner StateCA 
Aircraft Owner CountryUSA  
Aircraft Owner Zipcode95364 
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 certificateNone 
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)Instructional 
Second Pilot on BoardYes 
Departure Point Same as EventNo 
Departure Airport CodeL52  
Departure CitySAN LUIS OBISPO 
Departure StateCA 
Departure CountryUSA 
Departure Time1630 
Departure Time ZonePDT 
Destination Same as Local Flt-- 
Destination Airport Code3O8  
Destination CityHARRIS RANCH 
Destination StateCA 
Destination CountryUSA 
Specific Phase of FlightManeuvering - turn to landing area (emergency) 
Report sent to ICAO?No 
Evacuation occurredNo 
Date of most recent change to recordAug 11 2004 6:18PM 
User who most recently changed recordCOOS  
Since inspection or accidentTime of Accident 
Event Location Runway Number and LocationNA 
Runway Length-- 
Runway Width-- 
Sight Seeing flightNo 
Air Medical FlightNo 
Medical Flight--