American Airlines Flight 1399
Boeing 757-223 · Accident: in flight encounter with weather en route
From Miami International Airport (MIA) to Chicago O'Hare International Airport (ORD)
Event
- NTSB case
- CHI05LA135
- 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
- Visual Meteorological Cond
Boeing 757-223
- 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
- N602AN
- Operator
- American Airlines
- Onboard fatalities
- Unknown
- Route
- From Miami International Airport (MIA), Miami, 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 · descent
- 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 in clouds
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
During cruise descent the airplane encountered convectively induced turbulence (CIT) and two flight attendants were injured. One of the injured flight attendants was located in the aft galley preparing for landing when the airplane encountered the turbulence. The flight attendant stated that she heard the captain say "prepare for landing" and "all of [a] sudden I got lifted off the ground and slammed into the 4R door." This flight attendant suffered a fractured ankle. The other injured flight attendant was located near the aft lavatories preparing for landing when the airplane encountered the turbulence. The flight attendant stated that the airplane "hit some type of severe turbulence without warning" and that she was "thrown to the floor." This flight attendant suffered minor injuries to her shoulder, hip, foot, and lower back. Data from the airplane's Digital Flight Data Recorder (DFDR) was extracted and indicated that the airplane experienced vertical accelerations that were consistent with a CIT event. During the approximately 4 second CIT encounter, the maximum and minimum vertical accelerations were about 1.9g and 0.5g, respectively.
Probable cause
The inadvertent encounter with convectively induced turbulence (CIT) while the aircraft was descending into the terminal area.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI05LA135
- Event ID
- 20050616X00796
- Case number
- CHI05LA135
- 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, coordinates, 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: 3a0a2e21e47ec73bf463d61f0f431df2a5816b22ee55b971608c925a086777a0; retrieved 2026-09-18T15:02:02.880Z.
- The NTSB's operator name is blank for N602AN; the operator shown is the name the NTSB records it doing business as.