# NTSB DEN77FTE76: Stinson 108-2, N9389K, Boulder, CO, August 20, 1977

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: August 20, 1977
- Place: Boulder, CO · BOULDER, CO
- Location: 40.0244° N, 105.2513° W: Placed by OpenAirDocs: center of Boulder, CO, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.0244&lon=-105.2513&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report November 16, 1977
- Report: Brief approved by the director
- NTSB case key (mKey): 146015
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN77FTE76
- Page: https://openairdocs.org/ntsb/DEN77FTE76

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-3231  77/8/20    BOULDER, CO         STINSON 108-2       CR-  0  0  1  NONCOMMERCIAL             PRIVATE, AGE 34, 132
        TIME - 1130                    N9389K              PX-  0  0  2  PLEASURE/PERSONAL TRANSP  TOTAL HOURS, 96 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        NAME OF AIRPORT - BOULDER MUNI.
        DEPARTURE POINT             INTENDED DESTINATION
          BOULDER, CO                 LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            TAKEOFF: INITIAL CLIMB
           STALL: SPIN                                              LANDING: FINAL APPROACH
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - ATTEMPTED OPERATION W/KNOWN DEFICIENCIES IN EQUIPMENT
           PILOT IN COMMAND - INADEQUATE PREFLIGHT PREPARATION AND/OR PLANNING
           POWERPLANT - IGNITION SYSTEM: SPARK PLUG
           POWERPLANT - ENGINE STRUCTURE: VALVE ASSEMBLIES
           PILOT IN COMMAND - FAILED TO OBTAIN/MAINTAIN FLYING SPEED
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
         FIRE AFTER IMPACT
        REMARKS- NO. 6 CYLINDER PLUGS FOULED AND EXHAUST VALVE LEAKING
```

## Aircraft

- Registration: [N9389K](https://openairdocs.org/deregistered/N9389K-1977-11-08), registration cancelled 1977-11-08, S/N 108-2389, built 1947 (OpenAirDocs)
- Reported make and model: STINSON 108-2
- Registry model: [Stinson 108-2](https://openairdocs.org/model/stinson-108-2) (registry code 9230406) (OpenAirDocs)
- Category: Airplane
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Boulder Muni.

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19770820029449A](https://openairdocs.org/incident/19770820029449A), Aug 20, 1977: Univar 1082, Boulder, CO, Destroyed. No. 6 cylinder plugs fouled and exhaust valve leaking

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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