# NTSB ATL83LA120: Cessna 421, N123SM, Dayton, TN, February 24, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 24, 1983, 07:00 local (12:00 UTC)
- Place: Dayton, TN
- Coordinates: 35.489875, -85.010772 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.4899&lon=-85.0108&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6023
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL83LA120
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6023/pdf
- Page: https://openairdocs.org/ntsb/ATL83LA120

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight collision with object, approach - iaf to faf/outer marker (ifr)
  - object - tree(s) (contributing factor)
  - ifr procedure - improper use of, pilot in command (cause)
  - instrument approach procedure - incorrect

## Analysis

THE CESSNA 421 COLLIDED WITH TREES DURING THE LANDING APPROACH WHILE ON A CORPORATE FLIGHT. THE WEATHER WAS IMC AT THE ACCIDENT SITE AND THE ACFT WAS ON AN IFR FLIGHT PLAN. THE ACFT WAS SUBSTANTIALLY DAMAGED BUT THE PILOT WAS NOT INJURED. THE ACFT CONTACTED TREES 5 MILES NORTH OF THE AIRPORT. THE ACCIDENT OCCURRED DURING AN RNAV APPROACH TO RUNWAY 21 AT MARK ANTON FIELD, DAYTON, TN. THE PILOT STATED THAT AT WHAT HE THOUGHT TO BE THE FINAL APPROACH FIX A DESCENT WAS BEGUN FROM 2300 FT TO 1520 FT. AT 2000 FT COLLISION WITH TREES OCCURRED, (ON THE 170 DEGREE RADIAL 12 NM FROM THE HINCH MOUNTAIN VOR). A MISSED APPROACH WAS EXECUTED AND THE ACFT WAS FLOWN TO KNOXVILLE. NO MALFUNCTIONS WERE FOUND IN THE RNAV SYSTEM. THE PILOT SAID HE COULD HAVE 'MISSED KEYING IN' THE APPROPRIATE WAYPOINT.

## 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
- Serial number: 421-0193
- Airframe hours: 4065
- Engines: CONTINENTAL GTSIO-520D 375 horsepower reciprocating
- Damage: Substantial damage
- Flight: Executive/Corporate, Part 91
- Registered owner: Robinson Manufacturing Co./Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, October 20, 1982, 86 hours before
- Departed: TYS, KNOXVILLE, TN
- Flight plan: IFR
- Airport: 2A0, Mark Anton, runway 21, 4,500 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; flight instructor, airline transport; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 4,330 total, 300 in this make and model, 4,110 as pilot in command, 105 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 190° at 5 knots
- Visibility: 5 statute miles
- Lowest ceiling: 1,600 ft overcast
- Temperature: 48 °F, dew point 45 °F
- Altimeter: 29.00 inHg
- Observed at: CHA, 30 nm away

## 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 19830224005789A](https://openairdocs.org/incident/19830224005789A), Feb 24, 1983: Cessna 421, Dayton, TN, Substantial damage. Misdialed RNAV approach. Struck trees on final approach segment still in clouds. Remained airborne. Landed safe.

## 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 IAD79FA046](https://openairdocs.org/ntsb/IAD79FA046), May 4, 1979: Cessna 421 (N123SM), Sevierville, 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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