ATL05LA001 · Stinson 108
Stinson 108 · Accident: partial loss of engine power (mechanical failure) en route
From Birmingham-Shuttlesworth International Airport (BHM) to Ashland/Lineville Airport (26A)
Event
- NTSB case
- ATL05LA001
- 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
- Unknown
- 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
Stinson 108
- Aircraft type
- Stinson 108
- 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
- N40129
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Birmingham-Shuttlesworth International Airport (BHM), Birmingham, ALTo Ashland/Lineville Airport (26A), Ashland, AL
- 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
- Engine assembly, valve, exhaust › Failure
- Engine assembly, valve, exhaust › Fatigue
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot stated they were in cruise flight at 2,500 feet with a private pilot flying the airplane. The engine began to run rough and shudder. The pilot stated, "I have the controls" and the private pilot responded, "you have the controls." The pilot looked for a forced landing area and observed a country road and a field. He completed the emergency checklist and entered a downwind to land on the highway. He turned base and observed power poles, but he could not see any power lines running between the poles and decided to land in the field. He made a left 35-degree turn towards a field and propeller struck a tree, yawed to the left colliding with the ground separating the landing gear and bending the engine firewall. Examination of the engine assembly revealed the exhaust valve in the No.4 cylinder had failed. Examination of the exhaust valve revealed fatigue cracks had propagated from opposite sides of the stem adjacent to the beginning of the radius between the stem and the valve head.
Probable cause
A total loss of engine power in cruise flight due to the fatigue failure of the No.4 cylinder exhaust valve.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL05LA001
- Event ID
- 20041005X01564
- Case number
- ATL05LA001
- 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, coordinates. 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: 353c309b2cfc321d6a5c55c458fa9c7fa9c05a09b4304369a254936be7d07d32; retrieved 2026-09-21T19:07:40.928Z.