Southwest Airlines Flight 1257
Boeing 737-3H4 · Accident: in flight encounter with weather en route
From William P. Hobby Airport (HOU) to Louis Armstrong New Orleans International Airport (MSY)
Event
- NTSB case
- FTW99LA207
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Boeing 737-3H4
- Aircraft type
- Boeing 737
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N650SW
- Operator
- Southwest Airlines
- Onboard fatalities
- Unknown
- Route
- From William P. Hobby Airport (HOU), Houston, TXTo Louis Armstrong New Orleans International Airport (MSY), New Orleans, LA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- In flight encounter with weather
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Pilot in command › Flight into adverse weather, inadvertent
Approximate · Estimated position: the centre of Lafayette, LA, the place the record names. Not the accident site.
NTSB narrative
The flight encountered turbulence while at FL330. The destination airport was reporting thunderstorm activity near the airport. The fasten seat belt light had been turned on and the passengers briefed about the possibility of encountering turbulence during the approach. The airplane entered a stratus layer of clouds with a small cell approximately 20 miles to the left of the airplane's flight path. The captain reported that the airplane experienced a 'sudden jolt' followed by 10 to 12 seconds of light to occasionally moderate turbulence. The turbulence ceased once the airplane exited the clouds, with smooth air prevailing for the rest of the flight. A flight attendant in the aft cabin sustained a broken ankle.
Probable cause
The pilot's inadvertent flight into an adverse weather condition. A factor was the turbulence.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW99LA207
- Event ID
- 20001212X19008
- Case number
- FTW99LA207
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: local date, investigation status, damage. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1999-06-26.
- API snapshot SHA-256: 90c1f3c2be800b7a3592a1571e07dbb836174f166aa0eceaed0c5370d58f3236; retrieved 2026-09-18T16:55:43.906Z.
- The NTSB's operator name is blank for N650SW; the operator shown is the name the NTSB records it doing business as.