Aircraft Accident/Incident Report

Firebaugh, California 93622
Tuesady, June 28, 1994 19:54 PDT

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

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

Event Information

Type of Event Accident
Event Date 6/28/1994
Event Day of the Week Tuesday
Time of Event 1954
Event Time Zone Pacific Daylight Time
Event City FIREBAUGH
Event State CALIFORNIA
Event Country --
Zipcode of the event site 93622
Event Date Year 1994
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1958 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 155
Weather Observation Facility ID MER
Elevation of weather observation facility 188
Distance of event from weather observation facility (units?) 35
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 5000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 33
Dew Point at event time (in degress fahrenheit) 12
Wind Direction (degrees magnetic) 330
Variable Wind Indicator Unknown
Wind Speed (knots) 9
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) 2500
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 1275
NTSB Notification Source --
NTSB Notification Date Jun 28 1994 12:00AM
NTSB Notification Time 2130
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 6 2000 11:30AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4230X
NTSB Number LAX94LA268
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire In-flight
Aircraft Explosion Ground
Aircraft Manufacturer's Full Name ROCKWELL
Aircraft Model S2-R
Aircraft Series Identifier S2-R
Aircraft Serial Number 1996R
Certified Max Gross Weight 7000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Nov 15 1993 12:00AM
Airframe hours since last inspection 83
Airframe Hours 11036
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name TRI AIR, INC.
Aircraft Owner Street Address P.O. BOX 486
Aircraft Owner City FIREBAUGH
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 93622
Operator is an individual? --
Operator Name TRI AIR, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address P.O. BOX 486
Operator City FIREBAUGH
Operator State CA
Operator Country
Operator Zip code 93622
Operator Code RQCG
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Agriculture
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Aerial Application
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code Q49
Departure City
Departure State
Departure Country
Departure Time 1930
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code Q49
Destination City
Destination State
Destination Country
Specific Phase of Flight Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --