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NTSB Report
June 8, 1991 · Cessna 172N · N6230D
Thermal, CA
Overview
Report Status
Probable Cause
Event Type
Accident
Date
June 8, 1991
Injury Outcomes
2 injuries (2 minor injuries), 2 uninjured
Location
Thermal, CA
Aircraft
Cessna 172N
Tail Number
N6230D
Operator
Consair Flying Club
Injuries
Minor
Aircraft Damage
Substantial
NTSB Number
LAX91LA255
A CESSNA 172N NOSED OVER IN SOFT SOIL DURING LANDING ROLL AFTER A FORCED LANDING. THE PILOT INDICATED THAT THE ENGINE WAS RUNNING ROUGH AND LOSING POWER. THE PILOT LANDED THE AIRPLANE ON AN AIRPORT, BUT WAS UNABLE TO MANEUVER THE AIRPLANE TO A RUNWAY. THE AIRPLANE DECELERATED TO ABOUT 20 MPH DURING THE GROUND ROLL ON DIRT. THE AIRPLANE NOSED OVER AFTER THE NOSE GEAR STRUCK A 15 TO 18 INCH HIGH DIRT BANK. THE ENGINE WAS EXAMINED BY AN A&P MECHANIC. THE A&P FOUND THE NUMBER THREE CYLINDER INTAKE VALVE WAS 'TULIPED.' ACCORDING TO THE AIRPLANE'S MAINTENANCE RECORDS, THE ENGINE HAD ACCRUED 2,850 HOURS OF OPERATION WITHOUT OVERHAUL. FORTY FOUR HOURS OF OPERATION BEFORE THE ACCIDENT, THE ENGINE'S CYLINDER COMPRESSION CHECKED 'OK' DURING A LEAK TEST. THE ENGINE MANUFACTURER RECOMMENDED TIME BETWEEN OVERHAULS IS 1,500 HOURS. DURING OVERHAUL THE VALVES ARE REMOVED AND VISUALLY CHECKED FOR WEAR.
NTSB Probable Cause
THE PARTIAL FAILURE OF THE ENGINE/POWERPLANT FROM A WORN INTAKE VALVE AND THE FAILURE OF COMPANY/OPERATOR MANAGEMENT TO PERFORM AN OVERHAUL ON THE ENGINE WITHIN THE TIME FRAME RECOMMENDED BY THE ENGINE MANUFACTURER.
Full Narrative
A CESSNA 172N NOSED OVER IN SOFT SOIL DURING LANDING ROLL AFTER A FORCED LANDING. THE PILOT INDICATED THAT THE ENGINE WAS RUNNING ROUGH AND LOSING POWER. THE PILOT LANDED THE AIRPLANE ON AN AIRPORT, BUT WAS UNABLE TO MANEUVER THE AIRPLANE TO A RUNWAY. THE AIRPLANE DECELERATED TO ABOUT 20 MPH DURING THE GROUND ROLL ON DIRT. THE AIRPLANE NOSED OVER AFTER THE NOSE GEAR STRUCK A 15 TO 18 INCH HIGH DIRT BANK. THE ENGINE WAS EXAMINED BY AN A&P MECHANIC. THE A&P FOUND THE NUMBER THREE CYLINDER INTAKE VALVE WAS 'TULIPED.' ACCORDING TO THE AIRPLANE'S MAINTENANCE RECORDS, THE ENGINE HAD ACCRUED 2,850 HOURS OF OPERATION WITHOUT OVERHAUL. FORTY FOUR HOURS OF OPERATION BEFORE THE ACCIDENT, THE ENGINE'S CYLINDER COMPRESSION CHECKED 'OK' DURING A LEAK TEST. THE ENGINE MANUFACTURER RECOMMENDED TIME BETWEEN OVERHAULS IS 1,500 HOURS. DURING OVERHAUL THE VALVES ARE REMOVED AND VISUALLY CHECKED FOR WEAR.
Flight
Event TypeAccident
Event Time16:55 PDT
Nearest AirportTHERMAL (0nm)
Runway3
Runway Length4993 ft
Runway Width100 ft
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftCessna 172N
Tail NumberN6230D
Aircraft CategoryAir
DamageSubstantial
OperatorConsair Flying Club
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · O-320 H2AD · Reciprocating · 160
Seats4
People & Injuries
Injury Summary2 injuries (2 minor injuries), 2 uninjured
Fatal0
Serious0
Minor2
Uninjured2
Total4
Crew 1Age 30 · First Class
Conditions
ConditionsVMC
LightDaylight
Wind190° @ 9 kt
Visibility25 sm
CeilingNone
Temperature / Dew Point10 C / 27 C
Altimeter29.00 inHg
Observation Time23:53
Weather SourceWFAC