NYC99LA065 · Stinson 108-3
Stinson 108-3 · Accident: partial loss of engine power (mechanical failure) en route
From Skylark Airpark (7B6) to Danbury Municipal Airport (DXR)
Event
- NTSB case
- NYC99LA065
- 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
Stinson 108-3
- 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
- N6191M
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Skylark Airpark (7B6), East Windsor, CTTo Danbury Municipal Airport (DXR), Danbury, CT
- 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, connecting rod bolt › Fatigue
Approximate · Estimated position: the centre of Bristol, CT, the place the record names. Not the accident site.
NTSB narrative
The pilot stated that he heard a loud noise accompanied by a loss of engine power. A forced landing was executed to a field. Inspection of the engine after the accident revealed two holes in the top of the engine crankcase. The number 3 piston, and it's connecting rod and bolts, were removed from the engine and examined. One of the connecting rod bolts contained microfissures typical of fatigue cracking on the head portion of the bolt. The fatigue cracking had initiated from multiple locations on one side of the underhead radius, and had propagated nearly all of the way through the cross section of the bolt before final separation. A review of the Airplane Engine logbooks revealed that the last Major overhaul was conducted on March 3, 1965.
Probable cause
The partial loss of power due to the failure of a fatigued connecting rod bolt.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC99LA065
- Event ID
- 20001205X00235
- Case number
- NYC99LA065
- 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: 37593e0ed940e1aa936747204d65c7afb27b7b6803034624848d41d0d06eb6ee; retrieved 2026-09-22T15:49:28.377Z.