Southwest Airlines Flight 3633
Boeing 737 7H4 · Accident: turbulence encounter en route
From Manchester-Boston Regional Airport (MHT) to Baltimore/Washington International Thurgood Marshall Airport (BWI)
Event
- NTSB case
- DCA24LA256
- 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
- Event fatalities
- Unknown
- Ground fatalities
- Unknown
- 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
- Visual Meteorological Cond
Boeing 737 7H4
- 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
- N226WN
- Operator
- Southwest Airlines
- Onboard fatalities
- Unknown
- Route
- From Manchester-Boston Regional Airport (MHT), Manchester, NHTo Baltimore/Washington International Thurgood Marshall Airport (BWI), Baltimore, MD
- Aircraft age
- About 19 years (built 2005)
- 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 · descent
- Defining eventThe 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
- Turbulence encounter
- 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
- Environmental issues › Conditions/weather/phenomena
- Personnel issues › Action/decision
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
Southwest Airlines Flight 3633 (SWA 3633) encountered turbulence while descending through flight level (FL) 190 to Baltimore/Washington International Thurgood Marshall Airport (BWI), Baltimore, Maryland. The flight was a regularly scheduled domestic passenger flight from Manchester-Boston Regional Airport (MHT), Manchester, New Hampshire to BWI.
The flight crew illuminated the seat belt sign during descent into BWI. A few minutes following the illumination, a passenger stood up and walked to the back of the cabin. The flight attendant told the passenger to return to her seat, and the passenger responded that she would not return to her seat because she needed to stretch. About a minute later, as the aircraft descended through a cloud, the flight encountered short duration moderate turbulence. The standing passenger lost her balance and fell to the floor, breaking her ankle. Two nurses came to assist the passenger on the floor of the galley where they bandaged and splinted her ankle. The nurses returned to their seats for landing. An off-duty flight attendant sat on the floor of the galley with the injured passenger to secure her during landing. EMTs met the flight at the gate and transported the injured passenger from the airplane to a local hospital.
The flight crew reported that the there were no reports of turbulence or radar returns that would have indicated turbulence. A post flight review of weather showed no predicted turbulence or evidence of convection near the location and altitude where the encounter occurred.
Probable cause
A passenger’s failure to comply with crew member instructions to remain seated with seatbelt fastened.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DCA24LA256
- Event ID
- 20240809194882
- Case number
- DCA24LA256
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- 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: investigation status, coordinates, cause areas, damage. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 9aa80aee887a71e206d99ac056e005c1e2ebf00b0428b6db631ff88facb166b7; retrieved 2026-09-16T19:09:07.281Z.