CHI94FA340 · Beech E95A
Beech E95A · Accident: propeller failure/malfunction en route
From ATO · Waterloo, IA to Chicago Executive Airport (PWK)
Event
- NTSB case
- CHI94FA340
- 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
- 1 · 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 E95A
- Aircraft type
- Beechcraft 95
- 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
- N9581Y
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From ATO · Waterloo, IATo Chicago Executive Airport (PWK), Wheeling, 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 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
- Propeller failure/malfunction
- 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/spin
- 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 › Aircraft control, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PILOT DECLARED AN EMERGENCY WITH ATC AFTER EXPERIENCING WHAT HE BELIEVED WAS A LEFT ENGINE FAILURE. THE CONTROLLER GUIDED THE PILOT TO A NON-CONTROLLED AIRPORT FOR A LANDING. WITNESSES AT THE AIRPORT REPORTED SEEING THE AIRPLANE ENTER DOWNWIND FOR THE SOUTHEAST RUNWAY. THEY SAID THE AIRPLANE BEGAN A TURN FROM BASE LEG TO FINAL APPROACH. DURING THE TURN, THE AIRPLANE ENTERED A SPIN AND COLLIDED WITH THE GROUND. THE ON-SCENE INVESTIGATION REVEALED THAT ONE BLADE OF THE LEFT ENGINE PROPELLER BLADE HAD SEPARATED FROM THE ASSEMBLY. FURTHER EXAMINATION REVEALED THE SEPARATION WAS INITIATED BY A FATIGUE FRACTURE NEXT TO THE BLADE'S INNER CLAMP. TWO OF THE CLAMP SCREWS HAD FAILED DUE TO FATIGUE OVERLOAD. THE INNER CLAMP HAD BEEN ASSEMBLED WITH SCREWS THAT THE PROPELLER MANUFACTURER'S SERVICE BULLETIN SAID HAD TO BE CHANGED TO A DIFFERENT TYPE.
Probable cause
Aircraft control not maintained by the pilot when he began his turn from base leg to final approach. Factors associated with this accident were the fatigue failure of a propeller blade, improper maintenance overhaul of the propeller, and a material defect in the propeller blade clamp screws.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI94FA340
- Event ID
- 20001206X02193
- Case number
- CHI94FA340
- 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: 0f06a39f0e2461bf21a0184e1e32f91c85c1db0d186378b5c7b1697df592f458; retrieved 2026-09-21T00:00:09.845Z.