Aircraft Incident/Accident Report
Brownsville/South Padre Airport

Brownsville, Texas 78521
Wednesday, April 29, 1998 21:00 CDT

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NTSB Narrative Summary Released at Completion of Accident
While taxiing to takeoff, all four occupants of the DC-8 freighter became short of breath. They donned oxygen masks, and the flight returned to the ramp. Cargo included 960 pounds of dry ice (solid carbon dioxide) in 198 separate 4.85-pound blocks, used as a refrigerant for frozen shrimp. Sublimation of dry ice to the gaseous state occurs constantly. When the carbon dioxide (CO2) gas concentration reaches 0.5% shortness of breath may occur, at 2%, depth of respiration increases, and above 4%, breathing becomes rapid and very deep. At sea level and 70 degrees F (incident conditions were 23 feet msl and 66 degrees F), 0.4 pounds of CO2 gas in the cockpit of a DC-8 produces a 0.5% concentration and 3.3 pounds produces a 4% concentration. In 10 minutes, at sublimation rates of 1% and 14% per hour, 960 pounds of dry ice produces 1.6 and 22.4 pounds of CO2 gas, respectively. The 1% sublimation rate is commonly used when calculating amounts of dry ice that can safely be carried on aircraft; however, it was determined for bulk shipments of dry ice and may not be applicable to dry ice used as a refrigerant. The 14% rate was determined using a single 5 pound block of ice.
NTSB Probable Cause Narrative
The flightcrew experienced physical impairment resulting from an accumulation in the cockpit of carbon dioxide fumes produced by dry ice, a hazardous material, carried in the main cargo compartment.
Event Information
Type of EventIncident 
Event Date4/29/1998 
Event Day of the WeekWednesday 
Time of Event2100 
Event Time ZoneCentral Daylight Time 
Event CityBROWNSVILLE  
Event StateTEXAS 
Event Country-- 
Zipcode of the event site78521  
Event Date Year1998 
Event Date Month
MidAir Collision IndicatorNo 
On Ground Collision occurred ?No 
Event Location Latitude-- 
Event Location Longitude-- 
Event Location AirportBROWNSVILLE/SOUTH PADRE  
Event Location Nearest Airport IDBRO  
Indicates whether the acc/inc occurred off or on an airportOn Airport 
Distance from airport in statute miles-- 
Degrees magnetic from airport-- 
Airport Elevation23 
Weather Briefing CompletenessUnknown 
Investigator's weather sourceWeather Observation Facility 
Time of the weather observation2056 Central Daylight Time 
Direction of event from weather observation facility (degrees)
Weather Observation Facility IDBRO  
Elevation of weather observation facility23 
Distance of event from weather observation facility (units?)
Time Zone of the weather observationCDT 
Lighting ConditionsNight/Bright 
Lowest Ceiling Height
Lowest Non-Ceiling Height
Sky/Lowest/Cloud ConditionsClear 
Sky Condition for Lowest CeilingNone 
Visibility Runway Visual Range (Feet)
Visibility Runway Visual Value (Statute Miles)
Visibility (Statute Miles) 10 
Air Temperature at event time (in degrees celsius)19 
Dew Point at event time (in degress fahrenheit)15 
Wind Direction (degrees magnetic)50 
Variable Wind IndicatorUnknown 
Wind Speed (knots)
Wind Velocity Indicator Unknown 
Wind Gust IndicatorNot Gusting 
Wind Gust (knots)
Altimeter Setting at event time (in. Hg) 30 
Density Altitude (feet)-- 
Intensity of PrecipitationUnknown 
METAR weather report -- 
Event Highest InjuryMinor 
On Ground, Fatal Injuries
On Ground, Minor Injuries
On Ground, Serious Injuries
Injury Total Fatal-- 
Injury Total Minor
Injury Total None-- 
Injury Total Serious-- 
Injury Total All
Investigating AgencyNTSB 
NTSB Docket Number (internal use)5006 
NTSB Notification Source-- 
NTSB Notification DateApr 30 1998 12:00AM 
NTSB Notification Time930 
Fiche Number and/or location -used to find docket informationIMAGE 
Date of most recent change to recordFeb 23 2001 1:55PM 
User who most recently changed recorddbo  
Basic weather conditionsVisual Meteorological Cond 
FAA District Office-- 
Aircraft Involved
Aircraft #1
Aircraft Registration NumberN507DC 
NTSB NumberFTW98IA196  
Missing Aircraft Indicator
Federal Aviation Reg. PartPart 121: Air Carrier 
Type of Flight Plan filedIFR 
Flight plan Was Activated?-- 
DamageNone 
Aircraft FireNone 
Aircraft ExplosionNone 
Aircraft Manufacturer's Full NameDouglas  
Aircraft ModelDC-8-51  
Aircraft Series IdentifierDC-8-51  
Aircraft Serial Number45855  
Certified Max Gross Weight315000 
Aircraft CategoryAirplane 
Aircraft Registration ClassU.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
Number of Engines
Fixed gear or retractable gearRetractable 
Aircraft, Type of Last InspectionContinuous Airworthiness 
Date of Last InspectionApr 28 1998 12:00AM 
Airframe hours since last inspection
Airframe Hours3636 
ELT InstalledYes 
ELT ActivatedNo 
ELT Aided Location of Event SiteUnknown 
ELT Type-- 
Aircraft Owner NameAGRO AIR ASSOCIATES  
Aircraft Owner Street AddressPO BOX 524236  
Aircraft Owner CityMIAMI  
Aircraft Owner StateFL 
Aircraft Owner Country  
Aircraft Owner Zipcode33152  
Operator is an individual?-- 
Operator NameFINE AIRLINES, INC.  
Operator Same as Owner?No 
Operator Is Doing Business As-- 
Operator Address Same as Owner?No 
Operator Street Address4600 NW 36TH ST, BLDG 22  
Operator CityMIAMI  
Operator StateFL 
Operator Country  
Operator Zip code33122  
Operator CodeFXLA 
Owner has at least one certificateYes - certificate holder 
Other Operator of large aircraft?No 
Certified for Part 133 or 137 OperationUnknown 
Operator Certificate Number-- 
Indicates whether an air carrier operation was scheduled or notNon-scheduled 
Indicates Domestic or International FlightDomestic 
Operator carrying Pax/Cargo/MailCargo 
Type of Flying (Per_Bus / Primary)Unknown 
Second Pilot on BoardYes 
Departure Point Same as EventYes 
Departure Airport CodeBRO  
Departure City  
Departure State  
Departure Country  
Departure Time
Departure Time Zone  
Destination Same as Local Flt-- 
Destination Airport CodeLRD  
Destination CityLAREDO  
Destination StateTX 
Destination Country  
Specific Phase of Flight-- 
Report sent to ICAO?-- 
Evacuation occurred-- 
Date of most recent change to recordFeb 23 2001 1:55PM 
User who most recently changed recorddbo  
Since inspection or accident-- 
Event Location Runway Number and Location0  
Runway Length-- 
Runway Width-- 
Sight Seeing flightNo 
Air Medical FlightNo 
Medical Flight--