Northwest Airlines Flight 490
McDonnell Douglas DC-9-51 · Accident en route
From Hartsfield Jackson Atlanta International Airport (ATL) to Detroit Metropolitan Wayne County Airport (DTW)
Event
- NTSB case
- CHI01LA245
- 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
McDonnell Douglas DC-9-51
- Aircraft type
- McDonnell Douglas DC-9
- 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
- N780NC
- Operator
- Northwest Airlines
- Onboard fatalities
- Unknown
- Route
- From Hartsfield Jackson Atlanta International Airport (ATL), Atlanta, GATo Detroit Metropolitan Wayne County Airport (DTW), Detroit, MI
- 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
- Miscellaneous/other
- 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
- Passenger › Unsafe/hazardous condition warning, disregarded
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
An off duty flight attendant received a broken ankle when the airplane encountered moderate turbulence during descent. The captain reported the seat belt sign had been turned on and a passenger announcement was made regarding the likelyhood of encountering turbulence. The captain reported that light turbulence was encountered followed by moderate turbulence between an altitude of 18,000 feet and 12,000 feet. The injured off duty flight attendant reported, "Just before the descent began into Detroit, several passengers went to the lavatory and returned with no difficulty. I chose to give all other passengers the opportunity to go before I did. The flight was continuing smoothly as I made my way from my seat on the right side of the exit row, aft to the lavatory. While returning to my seat, the aircraft began to encounter some moderate turbulence as is normal while descending. I held to the seat backs to support myself as I walked forward toward my seat. As I neared my seat, the aircraft encountered a severe pocket of air with absolutely no warning whatsoever. I was lifted into the air as the aircraft dipped, then falling to the floor of the cabin. I could tell immediately that my ankle was broken because of its angle, and the terrible pain." A review of the flight data recorder data revealed the vertical acceleration of the airplane between 14,429 feet and 11,114 feet varied between .56 g's and 1.39 g's.
Probable cause
The passenger (an off duty flight attendant) disregarded the flight crews warning regarding turbulence along with the seat belt sign which had been turned on.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI01LA245
- Event ID
- 20010727X01542
- Case number
- CHI01LA245
- 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: 70f22a659f28db5547887489caaaa5767eea1a0ff0f3f66d34a6cef4cc140e25; retrieved 2026-09-18T16:11:22.131Z.
- The NTSB's operator name is blank for N780NC; the operator shown is the name the NTSB records it doing business as.