# NTSB CHI92LA236: Rockwell 112TC, N30MT, Winner, SD, August 7, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 7, 1992, 13:50 local (18:50 UTC)
- Place: Winner, SD
- Coordinates: 43.370384, -99.850891 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.3704&lon=-99.8509&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 3 minor
- Status: Completed, report May 8, 1993
- Report: Approved by Office Director
- Safety recommendations: Yes
- NTSB case key (mKey): 15512
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI92LA236
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15512/pdf
- Page: https://openairdocs.org/ntsb/CHI92LA236

## Probable cause

FAILURE OF THE CARBURETOR MIXTURE CONTROL, RESULTING IN LOSS OF ENGINE POWER.  A FACTOR RELATED TO THE ACCIDENT WAS: LACK OF COMPLIANCE WITH MARVEL-SCHEBLER SERVICE BULLETIN (SB) #A1-78.

## Sequence of events

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

- Loss of engine power, go-around (vfr)
  - maintenance,service bulletin/letter - not followed (contributing factor)
  - fuel system,carburetor - failure,total (cause)
  - mixture control - loose (cause)
- On ground/water collision with object, landing
  - object - fence
- On ground/water encounter with terrain/water, landing
  - terrain condition - rough/uneven

## Analysis

DRG A LNDG GO-AROUND, THE ENG BGN RUNNING ROUGH, THEN LOST PWR.  AN ATTEMPT WAS MADE TO MAKE AN EMERG LNDG ON A ROAD ADJACENT TO THE ARPT, BUT THE ACFT HIT A FENCE & AN EMBANKMENT BEFORE REACHING IT.  AN INV REVEALED THE LOSS OF POWER WAS DUE TO A MALFUNCTION OF THE ENG'S MARVEL-SCHEBLER MODEL HA-6 CARBURETOR (CARB).  EXCESSIVE WEAR OF THE SHAFT RETAINING SCREW ALLOWED MISPOSITIONING OF THE CARB'S ROTARY MIXTURE CONTROL (PN 242-541) AND BLOCKAGE OF FUEL FLOW.  IN SEP 78, MARVEL-SCHEBLER/TILLOTSON (ORIGINAL MANUFACTURER OF THE CARB) ISSUED SVC BULLETIN (SB) #A1-78, BUT IT HAD NOT BEEN ACCOMPLISHED.  THE SB PROVIDES FOR INSTLN OF A SPRING RETAINER (PN 55-A239) TO COUNTERACT END-PLAY WEAR ON THE MIXTURE CONTROL ASSEMBLY & RETAINING SCREW DUE TO VIBRATION.  THE SPRING RETAINER ALSO SERVES AS AN ADNL MEANS OF RETAINING THE ROTARY MIXTURE CONTROL, EVEN IF THE EXISTING SHAFT RETAINING SCREW IS WORN OR BKN.  THE ENG HAD A TOTAL FLT TIME OF 1065 HRS & 27 HRS SINCE THE LAST INSPN.

## Aircraft

- Registration: [N30MT](https://openairdocs.org/deregistered/N30MT-1993-04-28), registration cancelled 1993-04-28, S/N 13021 (OpenAirDocs)
- Reported make and model: Rockwell 112TC
- Registry model: [Rockwell International 112TC](https://openairdocs.org/model/rockwell-international-112tc) (registry code 7630306) (OpenAirDocs)
- Category: Airplane
- Serial number: 13021
- Airframe hours: 1065
- Engines: LYCOMING IO-360 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Duane T. Brooks
- Registered owner: Duane T. Brooks
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 1, 1992, 27 hours before
- Departed: BIE, BEATRICE, NE
- Destination: SD39, WINNER, SD
- Flight plan: IFR
- Airport: SD39, Bob Wiley Field, runway 13, 3,900 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 53; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 3,181 total, 715 in this make and model, 3,053 as pilot in command, 42 in the last 90 days, 34 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 4 knots
- Visibility: 20 statute miles
- Lowest ceiling: 2,000 ft broken
- Temperature: 75 °F, dew point 70 °F
- Altimeter: 29.00 inHg
- Observed at: PIR, 63 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 19920807029879A](https://openairdocs.org/incident/19920807029879A), Aug 7, 1992: Gulstm 112TC, Winner, SD, Substantial damage. Engine sputtered on go around over airport. Crash landed off airport. Mixture control shaft retaining screw failed.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.