# NTSB SEA91LA106: Beech A36, N6724T, Rawlins, WY, May 16, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: May 16, 1991, 05:12 local (11:12 UTC)
- Place: Rawlins, WY
- Coordinates: 41.780281, -107.220634 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.7803&lon=-107.2206&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41430
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91LA106
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41430/pdf
- Page: https://openairdocs.org/ntsb/SEA91LA106

## Probable cause

THE PILOT'S LACK OF FAMILIARITY WITH THE AIRCRAFT, HIS LACK OF UNDERSTANDING OF THE ELECTRICAL SYSTEM, AND A PREMATURE PRECAUTIONARY LANDING.  CONTRIBUTING TO THE ACCIDENT WERE AN ALTERNATOR FAILURE AND THE RESULTANT FALSE READINGS OF THE POWERPLANT INSTRUMENTS.

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - electrical system,alternator - failure,total (contributing factor)
  - engine instruments,tachometer - false indication (contributing factor)
  - engine instruments,fuel flow gage - false indication (contributing factor)
  - engine instruments,oil pressure gage - false indication (contributing factor)
  - engine instruments,oil temperature gage - false indication (contributing factor)
  - electrical system - not understood, pilot in command (cause)
  - lack of familiarity with aircraft, pilot in command (cause)
- Forced landing, descent - emergency
- Undershoot, landing
  - planned approach - poor, pilot in command (cause)

## Analysis

THE PILOT OF THE BEECH A36 WAS FLYING ON TOP OF AN OVERCAST WHEN HE NOTED THAT THE READINGS ON HIS ENGINE GAUGES WERE DROPPING.  HE DETERMINED THAT THE ALTERNATOR HAD FAILED AND WAS UNSUCCESSFUL IN HIS ATTEMPT TO USE THE STANDBY GENERATOR.  HE THEN DEAD-RECKONED TO A LET-DOWN THROUGH THE CLOUDS AT RAWLINS, WY, AND LANDED SHORT OF THE RUNWAY WHEN HE BELIEVED THAT THE ENGINE WAS NOT PRODUCING ADEQUATE POWER.

## Aircraft

- Registration: [N6724T](https://openairdocs.org/aircraft/N6724T), registered now, S/N E-2163, built 1984 (OpenAirDocs)
- Reported make and model: BEECH A36
- Registry model: [Beech A36](https://openairdocs.org/model/beech-a36) (registry code 1151604) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Airplane
- Serial number: E-2163
- Engines: CONTINENTAL IO-550-B 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Positioning, Part 91
- Operator: John L. Ronacher
- Departed: CPR, CASPER, WY
- Destination: OGD, OGDEN, UT
- Flight plan: IFR
- Airport: RWL, Rawlins Muni, runway 22, 7,000 × 100 ft

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 24; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 623 total, 35 in this make and model, 506 as pilot in command, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 340° at 15 knots
- Visibility: 5 statute miles
- Lowest ceiling: 1,800 ft broken
- Temperature: 39 °F, dew point 37 °F
- Altimeter: 30.00 inHg

## 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 19910516016259A](https://openairdocs.org/incident/19910516016259A), May 16, 1991: Beech A36, Rawlings, WY, Substantial damage. Believed lost oil pressure and partial power. Not so. Landed. Had lost alternator. Gauges were electrically operated

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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