9YTHR

Substantial
Serious

MCDONNELL DOUGLAS MD-83 S/N: 49568

Accident Details

Date
Sunday, October 3, 1993
NTSB Number
MIA94FA001
Location
MIAMI, FL
Event ID
20001211X13610
Aircraft Damage
Substantial
Highest Injury
Serious
Fatalities
0
Serious Injuries
1
Minor Injuries
1
Uninjured
80
Total Aboard
82

Probable Cause and Findings

THE FAILURE OF THE WATER HEATER RELAY AND THE OVERPRESSURE RELIEF VALVE TO OPERATE PROPERLY. IN ADDITION, THE DESIGN OF THE RELIEF VALVE WAS INADEQUATE IN THAT IT ALLOWED THE O-RING TO MIGRATE FROM ITS NORMAL POSITION PREVENTING THE VALVE FROM OPENING.

Aircraft Information

Registration
9YTHR
Make
MCDONNELL DOUGLAS
Serial Number
49568
Engine Type
Turbo-jet
Model / ICAO
MD-83 MD83
Aircraft Type
Fixed Wing Multi Engine
No. of Engines
2

Analysis

HISTORY OF FLIGHT

On October 3, 1993, about 1555 eastern daylight time, 9Y-THR, a McDonnell Douglas MD-83, experienced an explosion in the forward galley during climb to cruise altitude. The airplane was registered to and operating as British West Indies Airlines [BWIA] flight No. 431, scheduled, international, passenger service from Miami, Florida, to Barbados. The airplane was substantially damaged, 1 flight attendant received serious injuries, 1 flight attendant received minor injuries, 82 persons were not injured. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed. The flight had originated from Miami, Florida, about 1525 and landed back at Miami, Florida, around 1625 the same day.

Examination of the airplane revealed that a water heater, Nordskog model, had over pressurized and exploded. The entire forward galley and the cabin wall to the cockpit was destroyed. The water heater was removed and examined at the NTSB laboratory. All failures noted were consistent with overload. The over pressure valve was examined and the "O" ring had migrated blocking the valve "Pop Off" function. The electrical contacts to the heater element were found failed in a way that allowed constant power to the element. Details of these examinations are included in this report as attachments.

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# MIA94FA001