CHI96LA006 · Cessna 172F
Cessna 172F · Accident: partial loss of engine power (mechanical failure) en route
From Cumberland Municipal Airport (UBE) to an unrecorded destination
Event
- NTSB case
- CHI96LA006
- 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
Cessna 172F
- Aircraft type
- Cessna 172
- 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
- N8740U
- Operator
- John Watts
- Onboard fatalities
- Unknown
- Route
- From Cumberland Municipal Airport (UBE), Cumberland, WITo not recorded
- 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
- Partial loss of engine power (mechanical failure)
- 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
- Ignition system, magneto › Failure, partial
- Object › Sign
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PILOT REPORTED THAT HE WAS CRUISING AT 500 FEET ABOVE GROUND LEVEL WHEN THE 'ENGINE STARTED TO RUN ROUGHLY.' HE DECIDED TO LAND THE AIRPLANE AND 'INVESTIGATE THE PROBLEM.' ON LANDING ROLL THE AIRPLANE'S RIGHT WING TIP STRUCK A ROAD SIGN, THAT WAS OBSCURED BY BRUSH, WHICH 'SPUN THE AIRPLANE AROUND TO THE RIGHT.' THE AIRPLANE'S NOSE GEAR STRUCK A SAND EMBANKMENT ON THE ROAD'S EDGE AND NOSED OVER. EXAMINATION OF THE WRECKAGE FOUND THE LEFT MAGNETO REAR COVER HAD SEPARATED FROM THE MAGNETO'S MAIN CASE EXPOSING THE GEARS AND POINTS. THREE OF THE FOUR SCREWS WHICH HELD THE MAGNETO COVER IN PLACE WERE MISSING. THE FOURTH SCREW HAD SHEARED OFF IN THE CASE. BOTH MAGNETOS WERE TESTED FOR SPARK. NO ABNORMALITIES WERE FOUND. EXAMINATION OF FUEL IN THE TANKS SHOWED EVIDENCE OF WATER AND SEDIMENT.
Probable cause
the partial failure of the left magneto, the road sign, and the road embankment. A factor relating to this accident is the brush which obscured the road sign.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI96LA006
- Event ID
- 20001207X04660
- Case number
- CHI96LA006
- 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: 70a1439dd88881f1d490189aef00ea99bdd4c3fec0bfc6d9d69b01f8106ed6f7; retrieved 2026-09-22T23:10:09.728Z.