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NTSB Report
December 16, 1991 · Devenport EAA Biplane EAA Biplan · N9601
Wilksville, OH
Overview
Report Status
Probable Cause
Event Type
Accident
Date
December 16, 1991
Injury Outcomes
1 injury (1 minor injury)
Location
Wilksville, OH
Aircraft
Devenport EAA Biplane EAA Biplan
Tail Number
N9601
Operator
Jack F Holgate
Injuries
Minor
Aircraft Damage
Substantial
NTSB Number
NYC92DEG01
THE PILOT WAS IN CRUISE FLIGHT, IN AN EXPERIMENTALLY CERTIFIED AIRPLANE, WHEN THE CRANKCASE BREATHER WHICH WAS NOT PRESSURIZED WITH A WHISTLE SLOT FROZE UP. THE CRANKCASE PRESSURIZED AND THE CRANKCASE SEAL WAS DISLODGED. THE PILOT MADE A PRECAUTIONARY LANDING IN A FIELD OF LIMITED SIZE, SURROUNDED BY TREES. DUE TO THE RESTRICTED VIIBILITY OF THE PILOT, WITH OIL ON HIS GOGGLES AND WINDSHIELD, HE STRUCK A TREE ON FINAL AND MADE AN UNCONTROLLED TOUCHDOWN IN THE FIELD. THE INVESTIGATION REVEALED THERE IS A REQUIREMENT OF A WHISTLE SLOT ON NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES, HOWEVER, THIS REQUIREMENT DOES NOT EXIST FOR EXPERIMENTAL CATEGORY AIRPLANES.
NTSB Probable Cause
THE RESTRICTED VISIBILITY OF THE PILOT DUE TO OIL ON THE WINDSHIELD AND HIS GOGGLES, WHICH RESULTED IN A TREE STRIKE AND UNCONTROLLED TOUCHDOWN, DURING THE EXECUTION OF A PRECAUTIONARY LANDING. FACTORS RELATED TO THE ACCIDENT WERE A CLOGGED CRANKCASE BREATHER TUBE, THE LACK OF A WHISTLE SLOT ON THE CRANKCASE BREATHER TUBE, AND THE TREES.
Full Narrative
THE PILOT WAS IN CRUISE FLIGHT, IN AN EXPERIMENTALLY CERTIFIED AIRPLANE, WHEN THE CRANKCASE BREATHER WHICH WAS NOT PRESSURIZED WITH A WHISTLE SLOT FROZE UP. THE CRANKCASE PRESSURIZED AND THE CRANKCASE SEAL WAS DISLODGED. THE PILOT MADE A PRECAUTIONARY LANDING IN A FIELD OF LIMITED SIZE, SURROUNDED BY TREES. DUE TO THE RESTRICTED VIIBILITY OF THE PILOT, WITH OIL ON HIS GOGGLES AND WINDSHIELD, HE STRUCK A TREE ON FINAL AND MADE AN UNCONTROLLED TOUCHDOWN IN THE FIELD. THE INVESTIGATION REVEALED THERE IS A REQUIREMENT OF A WHISTLE SLOT ON NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES, HOWEVER, THIS REQUIREMENT DOES NOT EXIST FOR EXPERIMENTAL CATEGORY AIRPLANES.
Flight
Event TypeAccident
Event Time16:10 EST
Nearest Airport0nm N
Runway0
Flight Plan FiledVFR
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftDevenport EAA Biplane EAA Biplan
Tail NumberN9601
Aircraft CategoryAir
DamageSubstantial
OperatorJack F Holgate
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · O-290-D · Reciprocating · 70
Seats1
People & Injuries
Injury Summary1 injury (1 minor injury)
Fatal0
Serious0
Minor1
Uninjured0
Total1
Crew 1Age 50 · Third Class
Conditions
ConditionsVMC
LightDaylight
Wind8 kt
Visibility15 sm
CeilingOvercast 1000 ft
Temperature / Dew Point36 C / 0 C
Altimeter0
Observation Time21:00
Weather SourceWFAC