Northwest Airlines Flight 52
Boeing 757 · Accident: in flight encounter with weather en route
From San Francisco International Airport (SFO) to Detroit Metropolitan Wayne County Airport (DTW)
Narrative check · The NTSB narrative appears to contradict this record's location. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- CHI95LA271
- 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
- Visual Meteorological Cond
Boeing 757
- 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
- N509US
- Operator
- Northwest Airlines
- Onboard fatalities
- Unknown
- Route
- From San Francisco International Airport (SFO), San Francisco, CATo Detroit Metropolitan Wayne County Airport (DTW), 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 · 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
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE AIRPLANE HAD BEEN CLEARED TO DESCEND FROM FL410 TO FL230. THE ATC CONTROLLER AMENDED THE CLEARANCE TO FL270 SO THE FLIGHT WOULD HAVE A BETTER 'RIDE.' SHORTLY AFTER LEVELING OFF AT FL270, 25 NM EAST OF GRAND RAPIDS, MICHIGAN, SUDDEN, MODERATE TURBULENCE WAS ENCOUNTERED. A PASSENGER WHO WAS EXITING THE LAVATORY AT THE TIME FELL AND WAS SERIOUSLY INJURED. THE FLIGHT CREW STATED THE WEATHER RADAR DID NOT SHOW ANY WEATHER ON THE 80 MILE SCAN. THE SEAT BELT SIGN HAD BEEN ILLUMINATED ABOUT 5 MINUTES BEFORE THE TURBULENCE ENCOUNTER AND THE CAPTAIN MADE AN ANNOUNCEMENT FOR THE PASSENGERS TO EXPECT 'BUMPS' ON THE APPROACH. THE AIRPLANE'S LAVATORIES ARE EQUIPPED WITH A PUBLIC ADDRESS SPEAKER, A FLIGHT ATTENDANT CALL BUTTON, AND A 'RETURN TO SEAT' SIGN THAT IS ILLUMINATED WHEN THE CABIN SEAT BELT SIGN IS ACTIVATED. THE COMPANY'S DISPATCH/WEATHER DEPARTMENT'S WEATHER DATA SHOWED THE AIRPLANE HAD BEEN FLYING IN AN AREA OF 3/10'S COVERAGE OF LEVEL THREE AND FOUR THUNDERSTORMS.
Probable cause
the flight's encounter with turbulence.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI95LA271
- Event ID
- 20001207X04196
- Case number
- CHI95LA271
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: 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 1995-08-05.
- API snapshot SHA-256: 3842f764f42eaaf2b8639947130c1c2090f412c4a94aef925e0be1aaf618b9b4; retrieved 2026-09-18T17:58:31.375Z.