Ayres S2R accident near Tranquility, California, July 22, 1986
On July 22, 1986 at about 11:03 am local time, a Ayres S2R, registered N4023S, was destroyed in an accident near Tranquility, California (Western AG Av. airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 22, 1986 · about 11:03 am local time
- Place
- Tranquility, California · Western AG Av. · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Ayres S2R
- Registration
- N4023S · no longer on the register · serial R1820-004DC
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 4,950 hours in all
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 1,448 hours
- Last inspection: annual inspection, January 24, 1986; 10 hours since
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: Wright R-1820-97 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: San Joaquin CA at 10:15 am
- Flight plan: none
- Runway 0
Weather at the time
- Light: night, dark
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.