ATL96LA005 · Mooney M20K
Mooney M20K · Accident: total loss of engine power (mechanical failure) en route
From 8A4 · Marietta, GA to Cottonwood Airport (1C8)
Event
- NTSB case
- ATL96LA005
- 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
- Instrument Meteorological Cond
Mooney M20K
- Aircraft type
- Mooney M20
- 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
- N3983H
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 8A4 · Marietta, GATo Cottonwood Airport (1C8), Rockford, 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
- Total 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
- Engine assembly, connecting rod › Failure, total
- Fluid, oil › Starvation
- Maintenance, service of aircraft/equipment › Inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that during a climb through about 7,000 feet msl, the engine manifold pressure dropped to about 22 inches, and the engine oil pressure dropped to zero. He advised ATC that he would need to execute an emergency landing. During an emergency instrument landing procedure at dusk, he was unable to land on the intended runway, and the airplane impacted the terrain. Examination of the aircraft revealed old oil stains on the underside of the aircraft from the engine cowling trailing to the tail. Examination of the engine revealed that the number one and two connecting rods had failed as a result of thermal stretching and breaking of the rod bolts. No (new) oil leakage path was observed during the examination to indicate that the engine was leaking oil at the time of the accident.
Probable cause
Oil starvation for an unknown reason, which resulted in progressive connecting rod failure and subsequent loss of engine power. Factors relating to the accident were: the unfavoable weather and light conditions (low ceiling and fog at dusk), which hampered the pilot in seeing the runway during the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL96LA005
- Event ID
- 20001207X04634
- Case number
- ATL96LA005
- 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: 2828afdf00dbd2e11a81a6878f7db4d06d044d79c788545950ab99df390cfaa5; retrieved 2026-09-22T23:09:40.749Z.