CHI94LA277 · Beech C90A
University of North Dakota Beech C90A · Accident: uncontrolled altitude deviation en route
From Coleman A. Young Municipal Airport (DET) to Grand Forks International Airport (GFK)
Event
- NTSB case
- CHI94LA277
- 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
- General aviation
- 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
Beech C90A
- Aircraft type
- Beechcraft 90
- 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
- N1553N
- Operator
- University of North Dakota
- Onboard fatalities
- Unknown
- Route
- From Coleman A. Young Municipal Airport (DET), Detroit, MITo Grand Forks International Airport (GFK), Grand Forks, ND
- 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 91: General Aviation
- 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
- Uncontrolled altitude deviation
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Pilot in command › Design stress limits of aircraft, exceeded
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
WHILE IN CRUISE FLIGHT AT 20,000 FEET MEAN SEA LEVEL, AND MANEUVERING AROUND BUILD-UPS THE FLIGHT ENTERED IMC. SHORTLY AFTER ENTERING THE CLOUDS THE AIRPLANE ENCOUNTERED SEVERE TURBULENCE AND SOME OF THE FLIGHT INSTRUMENTS BECAME UNRELIABLE (TUMBLED). POSITIVE CONTROL OF THE AIRPLANE WAS REGAINED BETWEEN 16,800 AND 17,000 MSL. SUBSEQUENT EXAMINATION FOUND SUBSTANTIAL DAMAGE TO THE AIRFRAME.
Probable cause
the pilot-in-command's exceeding the design structural limits of the airplane. Factors were turbulence in clouds and the pilot- in-command;s continued flight into known adverse weather.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI94LA277
- Event ID
- 20001206X02002
- Case number
- CHI94LA277
- 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: investigation status. 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: ec688a1a2ecffef6274be225df10835b4039fc426d628ef622a1898a7266867b; retrieved 2026-09-23T00:47:55.075Z.