CHI94MA072 · Cessna 421C
Cessna 421C · Accident: airframe, component or system failure en route
From Denver International Airport (DEN) to Columbus Municipal Airport (OLU)
Event
- NTSB case
- CHI94MA072
- 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
- 2 · 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
- Charter & commuter
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Cessna 421C
- Aircraft type
- Cessna 421
- 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
- N5468G
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Denver International Airport (DEN), Denver, COTo Columbus Municipal Airport (OLU), Columbus, NE
- 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 135: Air Taxi & Commuter
- 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
- Airframe, component or system failure
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Stall; Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Pilot in command › In-flight planning/decision, improper
- Pilot in command › Stall, inadvertent
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PART 135 ON-DEMAND AIR TAXI FLIGHT DEPARTED DENVER, COLORADO, WITH A DESTINATION OF COLUMBUS, NEBRASKA. WEATHER FORECASTS WERE FOR ICING CONDITIONS ALONG THE ENTIRE ROUTE OF FLIGHT. WHILE EN ROUTE, ATC ADVISED THE PILOT OF REPORTED ICING AHEAD. THE PILOT WAS CLEARED TO CLIMB TO 19,000 FEET TO GET ON TOP OF THE CLOUDS. THE PILOT REPORTED 'SOME ALTERNATOR PROBLEMS,' AND REQUESTED TO DIVERT TO NORTH PLATTE, NEBRASKA. HE THEN ELECTED TO DIVERT TO MCCOOK, NEBRASKA, DUE TO THE WEATHER AT NORTH PLATTE. ATC LOST COMMUNICATION WITH THE PILOT DURING THE DIVERSION. WITNESSES REPORTED THE AIRPLANE CIRCLED THE MCCOOK AIRPORT TWICE. ACCORDING TO THEM, THE AIRPLANE ENTERED A BANK OF ABOUT 45 DEG, THEN STALLED. SUBSEQUENTLY, IT TRAVELED ABOUT 190 FEET THROUGH A STAND OF TREES BEFORE COMING TO REST. WITNESSES REPORTED THE AIRPLANE WAS COVERED WITH ICE. ONE-HALF INCH OF MIXED ICE WAS FOUND ON A PIECE OF WINDSHIELD. BOTH ALTERNATORS HAD ONE PHASE IN THE STATOR WINDING SHORTED.
Probable cause
IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT, AND THE ACCUMULATION OF AIRFRAME ICE, WHICH RESULTED IN AN INADVERTENT STALL. FACTORS ASSOCIATED WITH THE ACCIDENT WERE: PARTIAL FAILURE OF BOTH ALTERNATORS, WHICH RESULTED IN A SUBSEQUENT ELECTRICAL SYSTEM FAILURE AND AN INOPERATIVE ANTI-ICE/DE-ICE SYSTEM, ADVERSE WEATHER (ICING) CONDITIONS, AND AIRFRAME (WING) ICE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI94MA072
- Event ID
- 20001206X00614
- Case number
- CHI94MA072
- 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: 6cc42cc3c539311057dccd4f06f144584caf445a716ac09b5ffc70d9485bb2fe; retrieved 2026-09-18T13:50:23.880Z.