# NTSB ATL89LA121: Aero Commander 685, N685RB, Southern Pines, NC, April 5, 1989

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: April 5, 1989, 16:00 local (20:00 UTC)
- Place: Southern Pines, NC
- Coordinates: 35.180812, -79.400802 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.1808&lon=-79.4008&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 3 uninjured
- Status: Completed, report August 2, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 8010
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL89LA121
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8010/pdf
- Page: https://openairdocs.org/ntsb/ATL89LA121

## Probable cause

THE PILOT'S IMPROPER USE OF THE MIXTURE CONTROLS WHICH RESULTED IN ENGINE ROUGHNESS AND THE FAILURE TO PROPERLY EXECUTE THE EMERGENCY PROCEDURE FOR A ROUGH ENGINE BY PLACING THE FUEL BOOST PUMP SWITCH IN THE LOW POSITION.

## Sequence of events

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

- Loss of engine power(partial) - nonmechanical, cruise - normal
  - mixture - improper use of, pilot in command (cause)
  - emergency procedure - improper, pilot in command (cause)
  - fuel boost pump selector position - improper use of, pilot in command (cause)
- Forced landing, descent - emergency
- In flight collision with object, approach - vfr pattern - final approach
  - object - tree(s)
- Hard landing, landing - flare/touchdown

## Analysis

THE PLT REPORTED THAT DURING CRUISE FLIGHT AN ENG BEGAN RUNNING ROUGH. HE PUT THE FUEL BOOST PUMP SWITCH IN THE HIGH BOOST POSITION AND ADVANCED THE THROTTLE, MIXTURE, AND PROP LEVERS TO MAX. THIS RESULTED IN A LOSS OF PWR ON BOTH ENGS. THE ACFT TOUCHED DOWN HARD SHORT OF THE RUNWAY DURING THE FORCED LANDING AND COLLIDED WITH TREES. THE ACFT FLT MANUAL STATED THAT THE MIXTURE MUST BE ADJUSTED AT REDUCED POWER SETTINGS TO AVOID A RICH MIXTURE. THE EMERG PROCEDURES IN THE FLT MANUAL CAUTIONS THAT A ROUGH RUNNING ENG MAY BE DUE TO TOO RICH OF A MIXTURE.

## Aircraft

- Registration: [N685RB](https://openairdocs.org/deregistered/N685RB-2013-09-20), registration cancelled 2013-09-20, S/N 12059, built 1974 (OpenAirDocs)
- Reported make and model: AERO COMMANDER 685
- Registry model: [Aero Commander 685](https://openairdocs.org/model/aero-commander-685) (registry code 0141612) (OpenAirDocs)
- Registry engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 12059
- Airframe hours: 1791
- Engines: CONTINENTAL GTSIO-520-K1B 435 horsepower reciprocating
- Damage: Substantial damage
- Fire: On-Ground
- Flight: Business, Part 91
- Registered owner: Tcr Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, February 19, 1989, 21 hours before
- Departed: RDU, RALEIGH, NC
- Destination: DNL, AUGUSTA, GA
- Flight plan: IFR
- Airport: SOP, Moore County, runway 23, 5,503 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 5,000 total, 69 in this make and model, 5,000 as pilot in command, 133 in the last 90 days, 42 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 5 knots
- Visibility: 7 statute miles
- Lowest ceiling: 4,500 ft broken
- Altimeter: 29.00 inHg
- Observed at: POB, 18 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 19890405006199A](https://openairdocs.org/incident/19890405006199A), Apr 5, 1989: Gulstm 685, Southern Pines, NC, Substantial damage. Rough engines and powerloss en route. Flew thru trees on landing but made airport. Pilot used improper fuel setting

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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