- Date
- October 6, 1992, 11:00 local (18:00 UTC)
- Place
- El Mirage, CA
- Injuries
- 1 fatal
- Damage
- Destroyed
- Phase of flight
- Maneuvering
- Aircraft
- N4663ASwich II
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 14, 1993
- Report
- Approved by Office Director
- FAA report
- 19921006041019A
- Case key
- 27840
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
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.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
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.
Aircraft
- Registration
- N4663A
- Reported as
- Swich II
- Category
- Glider, amateur-built
- Serial number
- 2
- Airframe hours
- 72
- Engine
- Onan 4 CYCLE, 18 horsepower, reciprocating
- Damage
- Destroyed
- Flight
- Personal · Part 91
- Operator
- Irwin, Thomas M.
- Registered owner
- Irwin, Thomas M.
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Unknown · January 2, 2000
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 62
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 3, Expired
- Seat
- Center
- Toxicology
- Performed
- Flight hours
- 500 total · 72 in this make and model · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 40 statute miles
- Lowest ceiling
- None
- Temperature
- 84 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.