McDonnell Douglas MD-83 9YTHR
3 October 1993 · Miami, Florida, United States · Serious injuries
Summary
On 3 October 1993 at about 19:55 local time, a McDonnell Douglas MD-83 registered 9YTHR, operated by British West Indies, was involved in an accident near Miami, Florida, United States. 82 people were on board and one was seriously injured, one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.
The record
- Date
- at 19:55
- Classification
- Accident
- Location
- Miami, Florida, United States
- Coordinates
- Not recorded
- Aircraft
- McDonnell Douglas MD-83
- Registration
- 9YTHR
- Category
- Airplane
- Engines
- 2
- Operator
- British West Indies
- Operating rule
- Part 129: Foreign
- Purpose of flight
- Unknown
- Phase of flight
- Not recorded
- Route
- Unknown → Barbados
- Aircraft damage
- Substantial
- Weather
- VMC
- Light
- Day
- NTSB number
- MIA94FA001
People
1 person was seriously injured.
| On board | Died | Serious | Minor | Uninjured |
|---|---|---|---|---|
| 82 | 0 | 1 | 1 | 80 |
Probable cause
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.
Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.
Read the full NTSB narrative
THE WATER HEATER IN THE FORWARD GALLEY EXPLODED. EXAMINATION REVEALED THAT THE CONTACTS OF THE WATER HEATER RELAY, WHICH, WHEN ENERGIZED, PROVIDES ELECTRICAL POWER TO THE 3 HEATER ELEMENTS, WERE ROUGH, RAGGED, DISCOLORED, AND SHOWED EXCESSIVE EROSION. ACCORDING TO THE MANUFACTURER, WHEN A RELAY EXCEEDS ITS LIFETIME, IT IS POSSIBLE FOR EROSION AND WEAR ON THE SURFACE TO CAUSE THE CONTACTS TO STICK IN THE CLOSED POSITION. IN ADDITION, THE PRESSURE RELIEF VALVE, WHICH IS DESIGNED TO CRACK AT 65 PSI, WAS TESTED TO 300 PSI WITHOUT CRACKING. UPON DISASSEMBLY, THE O-RING WAS FOUND TO HAVE MIGRATED FROM ITS NORMAL LOCATION INTO THE LOWER VALVE BODY WHERE IT LODGED BETWEEN THE INSIDE DIAMETER AND THE HEAD OF THE POPPET. IN THIS CONDITION, THE O-RING PRESENTED A COMPLETED FLOW BLOCKAGE AND PREVENTED THE PRESSURE RELIEF VALVE FROM OPENING.
Quoted verbatim from the NTSB record.
Other McDonnell Douglas MD-83 accidents
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 18 Apr 1994 | McDonnell Douglas MD-83 | Seattle, Washington, United States | - | No injuries | - |
| 12 Nov 1995 | McDonnell Douglas MD-83 | East Granby, Connecticut, United States | - | Minor injuries | - |
| 22 Dec 1996 | McDonnell Douglas MD-83 | San Jose, California, United States | - | Serious injuries | - |
| 23 Nov 1997 | McDonnell Douglas MD-83 | Paris, France | AOM | No injuries | - |
| 18 Jun 1997 | McDonnell Douglas MD-83 | Las Vegas, Nevada, United States | - | No injuries | - |
| 25 Jul 1998 | McDonnell Douglas MD-83 | Saint Louis, Missouri, United States | Trans World Airlines | Minor injuries | - |
Other accidents in this area
| Date | Aircraft | Location | Operator | Outcome | Died |
|---|---|---|---|---|---|
| 1 Dec 1993 | Cessna 650 | Tampa, Florida, United States | - | No injuries | - |
| 17 Dec 1993 | Grumman G-44A | Leesburg, Florida, United States | - | Minor injuries | - |
| 31 Dec 1993 | Cessna 150F | Lantana, Florida, United States | Micro Aviation Inc. | Minor injuries | - |
| 3 Mar 1993 | Smith Ted Aerostar AEROSTAR 600 | Panama City, Florida, United States | Cherokee Leasing, Inc. | Fatal | 1 |
| 18 Jan 1993 | Cessna 140 | Niceville, Florida, United States | RAY, Robert G. | Serious injuries | - |
| 7 Mar 1993 | Piper PA-28-140 | Kissimmee, Florida, United States | Joseph V. Fera | Serious injuries | - |