Rockwell S2-R N4230X

Summary

On 29 June 1994 at about 02:54 local time, a Rockwell S2-R registered N4230X, operated by TRI Air, Inc., was involved in an accident near Firebaugh, California, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 June 1994 at 02:54

Classification

Accident

Location

Firebaugh, California, United States

Coordinates

36.8509, -120.5402

Aircraft

Rockwell S2-R

Registration

N4230X

Category

Airplane

Engines

1

Operator

TRI Air, Inc.

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX94LA268

1 person died.

THE PILOT'S LOSS OF AIRCRAFT CONTROL AS A RESULT OF INCAPACITATION FROM AN IN-FLIGHT SULFUR FIRE.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.