United Airlines Flight 1597
Boeing B757-200 · Accident: in flight encounter with weather en route
From Fort Lauderdale Hollywood International Airport (FLL) to Chicago O'Hare International Airport (ORD)
Event
- NTSB case
- CHI01LA154
- 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
- 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
- Not recorded
Boeing B757-200
- Aircraft type
- Boeing 757
- 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
- N563UA
- Operator
- United Airlines
- Onboard fatalities
- Unknown
- Route
- From Fort Lauderdale Hollywood International Airport (FLL), Fort Lauderdale, FLTo Chicago O'Hare International Airport (ORD), Chicago, IL
- 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
- Weather condition › Turbulence(thunderstorms)
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight was deviating around thunderstorm activity and while descending the aircraft encountered turbulence resulting in a broken ankle to a passenger. A company representative reported, "Before starting the descent from FL280 to FL240, an announcement was made to the cabin that the FASTEN SEATBELT sign was on and that turbulence was expected during the descent." In a written statement the First Officer reported, "After we encountered the turbulence, we contacted the purser via the interphone. The purser informed us that there was one passenger in a lavatory with an injury to the head, and a second passenger also in a lavatory with a broken ankle." The male passenger received a serious trimalleolar fracture to the left ankle, and the female passenger received a minor injury. The male passenger reported he had unfastened his seatbelt and proceeded to the lavatory at the rear of the airplane. He reported that the fasten seat belt sign was not illuminated when he left his seat, and the flight deck had not issued any advisories while he was waiting for the lavatory. He reported that while he was in the lavatory, the airplane encountered turbulence that led to his injury. The female passenger, who received a minor injury, reported she was in the lavatory when the airplane encountered turbulence.
Probable cause
the turbulence encountered during descent and the passenger failure to return to his seat.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI01LA154
- Event ID
- 20010608X01136
- Case number
- CHI01LA154
- 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: investigation status, 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: 11353fc9045099e49a233c04bd9938f80f1d219f054c839a2428a3afb435d859; retrieved 2026-09-18T16:12:50.914Z.
- The NTSB's operator name is blank for N563UA; the operator shown is the name the NTSB records it doing business as.