# NTSB LAX90DVM03: Illi Thunder Gull, N2223E, Calif Valley, CA, August 8, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: August 7, 1990, 19:00 local (Aug 8, 1990, 02:00 UTC)
- Place: Calif Valley, CA
- Coordinates: 35.30928, -120.269729 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.3093&lon=-120.2697&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 26587
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90DVM03
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26587/pdf
- Page: https://openairdocs.org/ntsb/LAX90DVM03

## Probable cause

POOR JUDGEMENT OF THE PILOT FROM USE OF A DRUG (COCAINE), AND THE PILOT ALLOWING THE DESIGN STRESS LIMITS OF THE AIRCRAFT TO BE EXCEEDED, WHILE MANEUVERING, WHICH RESULTED IN OVERLOAD FAILURE OF THE WING SPAR & WING SEPARATION.

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - judgment - poor, pilot in command (cause)
  - impairment(drugs), pilot in command (cause)
  - maneuver - initiated, pilot in command
  - design stress limits of aircraft - exceeded, pilot in command (cause)
  - wing,spar - overload
  - wing - separation
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

A WITNESS REPORTED THE AIRCRAFT WAS FLYING STRAIGHT AND LEVEL, THEN IT ENTERED AN ACCELERATING, DESCENDING, RIGHT TURN.  THE WITNESS THEN SAW PART OF THE RIGHT WING SEPARATE FROM THE AIRCRAFT.  A POST-ACCIDENT EXAMINTATION OF THE WRECKAGE DISCLOSED NO CONSTRUCTION, MATERIAL OR METALLURGICAL DEFECT.  BASED ON THE COMPUTED GROSS WEIGHT, CENTER OF GRAVITY, AND TRIM POSTION AT THE TIME OF THE ACCIDENT, THE AIRCRAFT DESIGNER CALCULATED THE TRIM SPEED WAS 10 MPH OVER THE MAXIMUM DESIGNED VNE.  TESTS OF THE PILOT'S BLOOD SHOWED A COCAINE LEVEL OF 2.2 MG/L AND BENZOYLECGONINE (METABOLITE OF COCAINE) AT 0.96 MG/L.

## Aircraft

- Registration: [N2223E](https://openairdocs.org/deregistered/N2223E-2013-09-24), registration cancelled 2013-09-24, S/N 912-1.5, built 1990 (OpenAirDocs)
- Reported make and model: ILLI THUNDER GULL (THUNDER GU)
- Registry model: [Illi URS THUNDER GULL](https://openairdocs.org/model/illi-urs-thunder-gull) (registry code 05616WV) (OpenAirDocs)
- Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 912-1.5
- Airframe hours: 52
- Engines: ROTAX 912 80 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Urs Peter Illi
- Airworthiness certificate: Special, Experimental (Special)
- Departed: NONE, SANTA MARGARITA, CA
- Destination: 6L3, CALIF VALLEY, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; student; medical: class 3, valid medical--no waivers/lim.; seat: center; toxicology performed; flight hours: 63 total, 46 in this make and model, 48 as pilot in command, 36 in the last 90 days, 22 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Lowest ceiling: none
- Temperature: 81 °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 19900807031509A](https://openairdocs.org/incident/19900807031509A), Aug 7, 1990: Amtr THUNDER GULL, California Vall, CA, Destroyed, 1 fatal. Full nose down trim caused dive that exceeded vne. 6 feet of right wing separated. Vertical crash. Cocaine noted.

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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