Rockwell S2-R accident near Firebaugh, California, June 29, 1994
On June 29, 1994 at about 2:54 am local time, a Rockwell S2-R, registered N4230X, was destroyed in an accident near Firebaugh, California. 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 PILOT'S LOSS OF AIRCRAFT CONTROL AS A RESULT OF INCAPACITATION FROM AN IN-FLIGHT SULFUR FIRE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 29, 1994 · about 2:54 am local time
- Place
- Firebaugh, California · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Rockwell S2-R
- Registration
- N4230X · no longer on the register · serial 1996R
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE AIRPLANE WAS LOADED WITH 2,000 POUNDS OF POWDERED SULFUR. A WITNESS SAID THE AIRPLANE HAD JUST COMPLETED A SPRAY RUN, AND BEGAN A LEFT TURN TO MAKE WHAT THE WITNESS ASSUMED WAS A SOUTHBOUND RUN ON THE FIELD. FLAMES WERE SEEN ON THE BOTTOM OF THE AIRPLANE IN THE VICINITY OF THE DISPENSER APPARATUS. THE AIRPLANE DESCENDED A LITTLE, STARTED TO CLIMB AGAIN, THEN SUDDENLY NOSED OVER AND DOVE VERTICALLY INTO THE GROUND. INFLIGHT AND POSTCRASH FIRE HAD TOTALLY CONSUMED ALL OF THE NON-STEEL AIRCRAFT COMPONENTS, AND THE FIRE SEEMED TO HAVE BEEN MORE INTENSE IN THE AREA OF THE CHEMICAL HOPPER AND SPRAY APPARATUS. THE CHEMICAL MANUFACTURER SAID THE POWDERED SULFUR DUST USED IN AG OPERATIONS IS A MODERATE FIRE HAZARD ACCORDING TO NFPA CRITERIA. THE COMPOUND HAS A FLASH POINT OF 374 DEG F, YET STUDIES SHOW THAT CLOUDS OF DUST MAY IGNITE AT IGNITION TEMPS OF 190 DEG IN DENSITY LIMITS OF LESS THAN 0.1 OUNCES PER CUBIC FOOT.
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; instrument: airplane
- Flight time: 2,000 hours in all; 1,000 in this make and model; 150 in the last 90 days; 50 in the last 30 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 11,036 hours
- Last inspection: annual inspection, November 15, 1993; 83 hours since
- Maximum gross weight: 7,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R-1340-AN1 (piston); 0 hours total
- Operator: Tri Air, INC.
The flight
- Departed from: Q49 at 2:30 am
- Destination: Q49
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 330° at 9 knots
- Visibility: 10 statute miles
- Sky: scat at 5,000 ft
- Temperature: 91°F (33°C), dew point 54°F (12°C)
- Altimeter: 29.00 inHg
- Observation at 2:58 am from MER, 35 miles away
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.