# NTSB SEA91LA053: Beech 95, N2772Y, Roundup, MT, February 18, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 18, 1991, 12:40 local (19:40 UTC)
- Place: Roundup, MT
- Coordinates: 46.439365, -108.510848 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.4394&lon=-108.5108&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41391
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91LA053
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41391/pdf
- Page: https://openairdocs.org/ntsb/SEA91LA053

## Probable cause

PARTIAL LOSS OF POWER FOR UNDETERMINED REASONS.

## 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
  - all engines
  - reason for occurrence undetermined (cause)
  - weather condition - clouds
- Forced landing, descent - emergency
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - ditch

## Analysis

WHILE AT CRUISE FLIGHT AND IN IMC, THE RIGHT ENGINE LOST PARTIAL POWER. THE PILOT STATED THAT WHILE HE WAS ASSESSING THE PROBLEM WITH THE RIGHT ENGINE, THE LEFT ENGINE ALSO LOST PARTIAL POWER.  THE PILOT DID NOT FOLLOW THE MANUFACTURER'S SINGLE ENGINE PROCEDURES, OR ENGINE ICE PROTECTION PROCEDURES.  THE AIRPLANE WAS UNABLE TO MAINTAIN ALTITUDE AND A FORCED LANDING WAS INITIATED.  DURING THE LANDING ROLL IN AN OPEN FIELD, THE AIRPLANE COLLIDED WITH A DITCH.  WEATHER FORECASTS CAUTIONED OF MODERATE RIME ICING IN THE PRECIPITATION.  BOTH ENGINES WERE TEST RUN AND FOUND TO OPERATE WITHIN NORMAL PARAMETERS.

## Aircraft

- Registration: [N2772Y](https://openairdocs.org/deregistered/N2772Y-1993-03-18), registration cancelled 1993-03-18, S/N TD149 (OpenAirDocs)
- Reported make and model: BEECH 95
- Registry model: [Beech 95](https://openairdocs.org/model/beech-95) (registry code 1153402) (OpenAirDocs)
- Category: Airplane
- Serial number: TD-149
- Engines: LYCOMING IO-360-A1A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Ross E. Rogers
- Registered owner: Ross E. Rogers
- Departed: LWT, LEWISTOWN, MT
- Destination: BFF, SCOTTSBLUFF, NE
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 1,461 total, 104 in this make and model, 1,375 as pilot in command, 83 in the last 90 days, 23 in the last 30 days

## Weather

- Conditions: Visual (VMC), Dawn
- Wind: 320° at 8 knots
- Visibility: 5 statute miles
- Lowest ceiling: 500 ft overcast
- Temperature: 30 °F, dew point -0 °F

## 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 19910218005429A](https://openairdocs.org/incident/19910218005429A), Feb 18, 1991: Beech 95, Roundup, MT, Substantial damage. Both engines quit in clouds en route,brokeout 500 feet. Landing struck ditch. Possible carb or induction system icing

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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