# NTSB SEA93FA033: Beech 35-33, N755AA, Riverton, UT, December 9, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: December 9, 1992, 15:45 local (22:45 UTC)
- Place: Riverton, UT
- Coordinates: 40.500667, -111.940399 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.5007&lon=-111.9404&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report September 28, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 42930
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA93FA033
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42930/pdf
- Page: https://openairdocs.org/ntsb/SEA93FA033

## Probable cause

TERRAIN CLEARANCE WAS NOT MAINTAINED. FACTORS TO THE ACCIDENT WERE: SNOW AND FLIGHT INTO KNOWN ADVERSE WEATHER.

## Analysis

IT WAS REPORTED BY THE PILOT'S SON THAT PRIOR TO DEPARTING FOR THE FLIGHT, THE PILOT WAS AWARE OF THE POOR WEATHER CONDITIONS ALONG THE ROUTE OF FLIGHT. THE SON AND ANOTHER PILOT WERE FLYING IN A TWIN ENGINE AIRPLANE, AND THE FATHER WAS IN THE SINGLE ENGINE AIRPLANE. THE SON STATED THAT HIS FATHER TOOK OFF ABOUT EIGHT MINUTES BEFORE THEIR FLIGHT AND TURNED TOWARD THE NORTHWEST, WHILE THE SON TOOK OFF AND TURNED TO THE NORTHEAST TO FOLLOW THE VALLEY SOUTH. THE SON REPORTED THAT THE WEATHER FRONT WAS RUNNING ACROSS THE VALLEY AND THAT LIGHT SNOW WAS FALLING AND VISIBILITY WAS POOR AT THE TIME. THE WRECKAGE WAS FOUND ALONG THE WEST SIDE OF THE VALLEY NEAR ROLLING HILLS APPROXIMATELY SEVEN MILES SOUTH OF THE AIRPORT. A WITNESS REPORTED THAT HE HEARD THE CRASH BUT COULD NOT SEE IT DUE TO THE FALLING SNOW. POST CRASH INVESTIGATION DID NOT REVEAL EVIDENCE OF A MECHANICAL FAILURE OR MALFUNCTION.

## Sequence of events

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

- In flight encounter with weather, maneuvering
  - weather condition - snow (contributing factor)
- In flight collision with terrain/water, maneuvering
  - flight into known adverse weather - attempted, pilot in command (contributing factor)
  - clearance - not maintained, pilot in command (cause)

## Aircraft

- Registration: [N755AA](https://openairdocs.org/deregistered/N755AA-1993-05-24), registration cancelled 1993-05-24, S/N CD100 (OpenAirDocs)
- Reported make and model: BEECH 35-33
- Registry model: [Beech 35-33](https://openairdocs.org/model/beech-35-33) (registry code 1151402) (OpenAirDocs)
- Category: Airplane
- Serial number: CD-100
- Airframe hours: 6472
- Engines: CONTINENTAL IO-470-J 225 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Porter, Howard K.
- Registered owner: Porter, Howard K.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 1, 1992, 34 hours before
- Departed: U42, SALT LAKE CITY, UT
- Destination: PVU, PROVO, UT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 59; private; airplane ratings: single-engine land, multi-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 990 total, 263 as pilot in command

## Weather

- Conditions: Day
- Wind: 350° at 11 knots
- Visibility: 2 statute miles
- Lowest ceiling: 2,400 ft overcast
- Temperature: 34 °F
- Altimeter: 30.00 inHg
- Observed at: SLC, 17 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 19921209049529A](https://openairdocs.org/incident/19921209049529A), Dec 9, 1992: Beech 3533, Riverton, UT, Destroyed, 1 fatal. Took off into known poor weather. Snow and poor visibility. Struck rolling hills edge of valley.

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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