# NTSB LAX93LA005: Swich II, N4663A, El Mirage, CA, October 6, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: October 6, 1992, 11:00 local (18:00 UTC)
- Place: El Mirage, CA
- Coordinates: 38.560878, -121.99015 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.5609&lon=-121.9901&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report September 14, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27840
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA005
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27840/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA005

## 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

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, maneuvering
  - vertical stabilizer attachment - improper (contributing factor)
  - aircraft performance - deteriorated (contributing factor)
  - maintenance,installation - improper, pilot in command (cause)
  - acft/equip,inadequate design, pilot in command (contributing factor)
  - stall - intentional, pilot in command (contributing factor)
  - stall/spin - inadvertent, pilot in command (contributing factor)
  - remedial action - not possible, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## 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](https://openairdocs.org/deregistered/N4663A-1999-10-29), registration cancelled 1999-10-29, S/N 2 (OpenAirDocs)
- Reported make and model: SWICH II
- Registry model: [Irwin Thomas M SWISH II](https://openairdocs.org/model/irwin-thomas-m-swish-ii) (registry code 0563914) (OpenAirDocs)
- Category: Glider, amateur-built
- Serial number: 2
- Airframe hours: 72
- Engines: 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

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; 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 (OpenAirDocs).

- [Accident 19921006041019A](https://openairdocs.org/incident/19921006041019A), Oct 6, 1992: Amtr SWICH11, El Mirage, CA, Destroyed, 1 fatal. Plummeted to ground in a spin while practicing maneuvers. First flight after installing new vertical stabilizer.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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