# NTSB LAX86FVA12: Ayres S2R, N4023S, Tranquility, CA, July 22, 1986

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: July 22, 1986, 04:03 local (11:03 UTC)
- Place: Tranquility, CA
- Coordinates: 36.589443, -120.190292 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.5894&lon=-120.1903&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report March 10, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 24964
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX86FVA12
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24964/pdf
- Page: https://openairdocs.org/ntsb/LAX86FVA12

## Sequence of events

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

- Loss of control - in flight, maneuvering - turn to reverse direction
  - reason for occurrence undetermined (cause)
  - stall/spin - uncontrolled, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - open field (contributing factor)

## Analysis

DURING AN AERIAL APPLICATION OPERATION THE AIRCRAFT WAS OBSERVED TO HAVE MADE A PASS OVER THE FIELD, BEGAN TURNING TO MAKE ANOTHER PASS WHEN A LOUD POP WAS HEARD. JUST AFTER THE NOISE, WITNESSES OBSERVED THE AIRCRAFT SPIN AS THE TURN LIGHTS MOUNTED ON THE WINGS WERE OBSERVED TO ROTATE WITH THE AIRPLANE. NO PREIMPACT MECHANICAL MALFUNCTION/FAILURE WAS FOUND.

## Aircraft

- Registration: [N4023S](https://openairdocs.org/deregistered/N4023S-1988-06-03), registration cancelled 1988-06-03, S/N R1820004DC (OpenAirDocs)
- Reported make and model: AYRES S2R
- Registry model: [Ayres S2R-R1820](https://openairdocs.org/model/ayres-s2r-r1820) (registry code 0970215) (OpenAirDocs)
- Category: Airplane
- Serial number: R1820-004DC
- Airframe hours: 1448
- Engines: WRIGHT R-1820-97 1100 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Aerial application, Part 137
- Registered owner: Grouleff Aviation Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, January 24, 1986, 10 hours before
- Departed: SAN JOAQUIN, CA
- Airport: Western Ag Av.

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 4,950 total

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: calm
- Lowest ceiling: none

## 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 19860722035369A](https://openairdocs.org/incident/19860722035369A), Jul 22, 1986: Ayres S2RR1820, Tranquility, CA, Destroyed. Crashed, burned after pull up from spray run. Witnesses heard a pop and saw aircraft spin as turn lights rotated.

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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