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DEN92LA017 · Stinson 108-1

22 Dec 1991 · Longmont, CO, United States

Stinson 108-1 · Accident: partial loss of engine power (mechanical failure) during initial climb

From an unrecorded airport to EMD · Emporia, KS

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Event

NTSB case
DEN92LA017
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 108-1

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
N97962
Onboard fatalities
Unknown
Route
From not recordedTo EMD · Emporia, KS
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
Initial climb
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
Destroyed

Cause areas

No findings designated as a cause are recorded in the NTSB data yet.

Approximate · Estimated position: the centre of Longmont, CO, the place the record names. Not the accident site.

NTSB narrative

ON INITIAL CLIMB FOLLOWING TAKEOFF, AT A GROSS WEIGHT APPROXIMATELY 50 POUNDS OVER MAXIMUM, THE AIRPLANE WOULD NEITHER CLIMB NOR ACCELERATE. AFTER TURNING CROSSWIND AT 250 FEET AGL AND 1/2 MILE BEYOND THE RUNWAY END, ENGINE RPM BEGAN TO 'CREEP DOWN.' THE PILOT WAS UNABLE TO RESTORE RPM, THEREFORE, A FORCED LANDING WAS PERFORMED IN A PASTURE. THE AIRPLANE COLLIDED WITH A DITCH AND FENCE, NOSED OVER, AND CAUGHT FIRE. AN ENGINE EXAMINATION REVEALED THAT THE SPARK PLUGS WERE FOULED, MAGNETO IMPULSE COUPLING WEAK, AND RUST AND EVIDENCE OF DETONATION WAS PRESENT IN THE CYLINDERS AND ON PISTON DOMES, WHICH DEGRADED POWER AVAILABLE.

Probable cause

A LOSS OF ENGINE POWER DUE TO FOULED SPARK PLUGS. THE INADEQUATE MAINTENANCE OF THE ENGINE WAS A FACTOR IN THE ACCIDENT.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record DEN92LA017
Event ID
20001212X18587
Case number
DEN92LA017
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: a4464195d6ea059f038dcc28570eef5bbcac55039f197b798449a6fbe188764b; retrieved 2026-09-21T23:22:26.405Z.