CEN12LA501 · Beech H35
Beech H35 · Accident: loss of engine power (total) en route
From Wood County Airport - Collins Field (JDD) to Fox Stephens Field Gilmer Municipal Airport (JXI)
Event
- NTSB case
- CEN12LA501
- 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
Beech H35
- Aircraft type
- Beechcraft 35
- 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
- N4684D
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Wood County Airport - Collins Field (JDD), Mineola, TXTo Fox Stephens Field Gilmer Municipal Airport (JXI), Gilmer, TX
- 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 · descent
- Defining eventThe 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
- Loss of engine power (total)
- 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
- Aircraft › Aircraft power plant
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airplane’s engine lost power during the descent to the destination airport, and the airplane struck trees during the ensuing forced landing attempt. A postaccident examination of the engine revealed that the idler gear pin was not in position and no retaining bolts were found. Additionally, the nuts from the forward left, lower through bolt on the crankcase half and the forward left engine mount bolt were missing. A logbook entry indicated that the engine had been reassembled and re-installed on the airplane about 1 week before the accident due to a previous propeller strike. Based on the available information, it is likely that the improper assembly of the engine, specifically the omission of the idler gear pin retaining bolts, resulted in the idler gear falling out of its position and a subsequent complete loss of engine power.
Probable cause
The incomplete maintenance performed by maintenance personnel, which resulted in a total loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN12LA501
- Event ID
- 20120802X92317
- Case number
- CEN12LA501
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: 352c51fd813b3ad421b7f7a4113cab0e98f2c14a94ff87c8ec792237296629dc; retrieved 2026-09-15T19:13:38.456Z.