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NTSB Report
October 6, 1992 · Swich II · N4663A
El Mirage, CA
Overview
Report Status
Probable Cause
Event Type
Accident
Date
October 6, 1992
Injury Outcomes
1 injury (1 fatality)
Location
El Mirage, CA
Aircraft
Swich II
Tail Number
N4663A
Operator
Irwin Thomas M
Injuries
Fatal
Aircraft Damage
Destroyed
NTSB Number
LAX93LA005
THE PILOT WAS CONDUCTING A LOCAL PERSONAL FLIGHT OVER A DRY LAKE TO TEST A MODIFICATION ON THE MOTORIZED GLIDER. THE PILOT TOLD FRIENDS THAT HE INTENDED TO 'DO SOME STALLS.' AFTER EXECUTING SOME BASIC TURNS AND TAKEOFFS AND LANDING, THE PILOT DEPARTED THE AREA. A WITNESS OBSERVED THE AIRCRAFT IN A SPIN AND SAW IT CRASH. THE PILOT/OWNER RECENTLY INSTALLED A VERTICAL STABILIZER BETWEEN THE EXISTING RUDDERVATORS FOR BETTER LATERAL STABILITY IN THE MOTORIZED GLIDER. EXAMINATION OF THE WRECKAGE DISCLOSED NO EVIDENCE OF ANY PREEXISTING CONTROL MALFUNCTIONS OR FAILURES. A HOME BUILT DESIGN ENGINEER REPORTED THAT THE INCLUSION OF THE VERTICAL STABILIZER WOULD ADVERSELY EFFECT THE SPIN RECOVERY CHARACTERISTICS OF THE AIRCRAFT BY BLANKING OUT THE SIDE OF THE RUDDERVATOR OPPOSITE TO THE SPIN.
NTSB Probable Cause
THE PILOT/OWNER'S IMPROPER INSTALLATION OF THE VERTICAL STABILIZER. CONTRIBUTING TO THIS ACCIDENT WAS THE PILOT'S INTENTIONAL STALL, INADVERTENT SPIN, AND INABILITY TO RECOVER FROM THE SPIN DUE TO THE INADEQUATE EQUIPMENT (VERTICAL STABILIZER) DESIGN.
Full Narrative
THE PILOT WAS CONDUCTING A LOCAL PERSONAL FLIGHT OVER A DRY LAKE TO TEST A MODIFICATION ON THE MOTORIZED GLIDER. THE PILOT TOLD FRIENDS THAT HE INTENDED TO 'DO SOME STALLS.' AFTER EXECUTING SOME BASIC TURNS AND TAKEOFFS AND LANDING, THE PILOT DEPARTED THE AREA. A WITNESS OBSERVED THE AIRCRAFT IN A SPIN AND SAW IT CRASH. THE PILOT/OWNER RECENTLY INSTALLED A VERTICAL STABILIZER BETWEEN THE EXISTING RUDDERVATORS FOR BETTER LATERAL STABILITY IN THE MOTORIZED GLIDER. EXAMINATION OF THE WRECKAGE DISCLOSED NO EVIDENCE OF ANY PREEXISTING CONTROL MALFUNCTIONS OR FAILURES. A HOME BUILT DESIGN ENGINEER REPORTED THAT THE INCLUSION OF THE VERTICAL STABILIZER WOULD ADVERSELY EFFECT THE SPIN RECOVERY CHARACTERISTICS OF THE AIRCRAFT BY BLANKING OUT THE SIDE OF THE RUDDERVATOR OPPOSITE TO THE SPIN.
Flight
Event TypeAccident
Event Time11:00 PDT
Nearest Airport0nm N
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftSwich II
Tail NumberN4663A
Aircraft CategoryGli
DamageDestroyed
OperatorIrwin Thomas M
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsOnan · 4 CYCLE · Reciprocating · 18
Seats1
People & Injuries
Injury Summary1 injury (1 fatality)
Fatal1
Serious0
Minor0
Uninjured0
Total1
Crew 1Age 62 · Third Class
Conditions
ConditionsVMC
LightDaylight
WindCalm
Visibility40 sm
CeilingNone
Temperature / Dew Point0 C
Altimeter0
Weather SourceWIT