# NTSB IAD79FA046: Cessna 421, N123SM, Sevierville, TN, May 4, 1979

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: May 4, 1979
- Place: Sevierville, TN · SEVIERVILLE, TN
- Location: 35.8897° N, 83.5799° W: Placed by OpenAirDocs: center of Sevierville, TN, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=35.8897&lon=-83.5799&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report July 10, 1979
- Report: Brief approved by the director
- NTSB case key (mKey): 136236
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD79FA046
- Page: https://openairdocs.org/ntsb/IAD79FA046

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1047   79/5/4    SEVIERVILLE,TN      CESSNA 421          CR-  0  0  1  COMMERCIAL                COMMERCIAL, AGE 32, 1995
        TIME - 1130                    N123SM              PX-  0  0  2  AIR TAXI-PASSG            TOTAL HOURS, 420 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            INSTRUMENT RATED.
        NAME OF AIRPORT - SEVIER-GATLINBURG
        DEPARTURE POINT             INTENDED DESTINATION
          KNOXVILLE,TN                SEVIERVILLE,TN
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           UNDERSHOOT                                               LANDING: FINAL APPROACH
           GEAR COLLAPSED                                           LANDING: ROLL
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - MISJUDGED DISTANCE AND ALTITUDE
        FACTOR(S)
           AIRPORTS/AIRWAYS/FACILITIES - AIRPORT CONDITIONS: OTHER
           MISCELLANEOUS ACTS,CONDITIONS - OVERLOAD FAILURE
        REMARKS- AIRCRAFT STRUCK OPEN DRAINAGE DITCH AFTER LEAVING RUNWAY.
```

## Aircraft

- Registration: [N123SM](https://openairdocs.org/deregistered/N123SM-2026-04-29), registration cancelled 2026-04-29, S/N 421-0193, built 1968 (OpenAirDocs)
- Reported make and model: CESSNA 421
- Registry model: [Cessna 421](https://openairdocs.org/model/cessna-421) (registry code 2076010) (OpenAirDocs)
- Registry engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035, reciprocating) (OpenAirDocs)
- Category: Airplane
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Sevier-Gatlinburg

## 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 19790504015089A](https://openairdocs.org/incident/19790504015089A), May 4, 1979: Cessna 421, Sevierville, TN, Substantial damage. Pilot undershot runway. When landing gear hit edge of runway, the right main gear collapsed.

## Other investigations on N123SM (2)

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.

- [NTSB CEN23LA267](https://openairdocs.org/ntsb/CEN23LA267), Jun 24, 2023: Cessna 421 (N123SM), Rockport, TX, substantial damage. Probable cause: The failure of the left engine starter adapter gear, which resulted in catastrophic damage to other engine components, and the subsequent loss of engine power.
- [NTSB ATL83LA120](https://openairdocs.org/ntsb/ATL83LA120), Feb 24, 1983: Cessna 421 (N123SM), Dayton, TN, substantial damage

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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