CEN15FA424 · Beech S35
Beech S35 · Accident: loss of engine power (total) while maneuvering
From Durango La Plata County Airport (DRO) to Stevens Field (PSO)
Event
- NTSB case
- CEN15FA424
- 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
- 2 · 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 S35
- 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
- N193Q
- Operator
- Bennett Robert D
- Onboard fatalities
- Unknown
- Route
- From Durango La Plata County Airport (DRO), Durango, COTo Stevens Field (PSO), Pagosa Springs, CO
- Aircraft age
- About 51 years (built 1964)
- 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
- Maneuvering · low-altitude flying
- 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
- Destroyed
Cause areas
- Aircraft › Aircraft power plant
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
On the day before an air race competition, the accident pilot and another pilot decided to execute a practice circuit of the race course in their airplanes. As the two airplanes entered the course, the accident airplane was behind the other airplane. After they passed the first course waypoint, the accident pilot radioed the other pilot and stated that his airplane's engine had lost power and that the airplane was going down. No further communications were heard from the accident airplane. Witnesses observed white smoke coming from the underside of the airplane before they lost sight of it. Examination of the accident site indicated that the pilot was attempting to land on a gravel road when the airplane impacted a steel pole adjacent to the road and traveled about 200 yards before coming to rest inverted. Examination of the engine showed that the No. 6 connecting rod failed due to oil starvation. The oil starvation resulted from movement of the No. 4 main crankshaft bearing to a position where it blocked the oil transfer passage to the No. 6 connecting rod. The engine thru-bolts were improperly torqued by unknown maintenance personnel, and this allowed the No. 4 main bearing movement to occur. In addition, disassembly of the engine revealed that unapproved pistons had been installed. However, the unapproved pistons were not related to the engine failure.
Probable cause
Improper engine assembly by unknown maintenance personnel, which resulted in the failure of the No. 6 connecting rod due to oil starvation from the shifting of the crankshaft's No. 4 main bearing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN15FA424
- Event ID
- 20150925X72014
- Case number
- CEN15FA424
- 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. 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: ce87a1d49b9386568dcb0ae89841404b043da14b6f1d1e24cc07a6977cd4a6e0; retrieved 2026-09-14T21:31:29.505Z.