# NTSB DEN91FA049: Beech F33A, N4179S, Sterling, CO, March 10, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: March 10, 1991, 11:00 local (18:00 UTC)
- Place: Sterling, CO
- Coordinates: 40.620899, -103.190071 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.6209&lon=-103.1901&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18016
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN91FA049
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18016/pdf
- Page: https://openairdocs.org/ntsb/DEN91FA049

## Probable cause

POOR JUDGEMENT OF THE PILOT AND HIS MISJUDGEMENT OF ALTITUDE WHILE BUZZING OVER GLASSY WATER.  HIS LACK OF VISUAL QUES TO JUDGE ALTITUDE OVER GLASSY WATER WAS A RELATED FACTOR.

## Sequence of events

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

- In flight collision with terrain/water, maneuvering
  - judgment - poor, pilot in command (cause)
  - buzzing - intentional, pilot in command (cause)
  - terrain condition - water,glassy (contributing factor)
  - altitude - misjudged, pilot in command (cause)
  - visual/aural perception, pilot in command (contributing factor)

## Analysis

A YOUNG PILOT AND HIS PASSENGER FRIEND WERE OBSERVED `BUZZING' THE STERLING, COLORADO, WATER RESERVOIR. THE WITNESSES STATED THAT THE AIRCRAFT WAS SKIMMING THE GLASSY SURFACE OF THE WATER WHEN IT STRUCK THE WATER, PITCHED UP ABRUPTLY, THEN NOSED DOWN UNTIL IT IMPACTED THE WATER AND SANK.

## Aircraft

- Registration: [N4179S](https://openairdocs.org/deregistered/N4179S-1991-06-21), registration cancelled 1991-06-21, S/N CE572 (OpenAirDocs)
- Reported make and model: BEECH F33A
- Registry model: [Beech F33A](https://openairdocs.org/model/beech-f33a) (registry code 1151425) (OpenAirDocs)
- Category: Airplane
- Serial number: CE-572
- Engines: CONTINENTAL IO-520-BA 285 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Alfred Ward & Son
- Registered owner: Alfred Ward & Son
- Departed: AKO, AKRON, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 20; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; toxicology performed; flight hours: 297 total, 5 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: -0 °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 19910310004779A](https://openairdocs.org/incident/19910310004779A), Mar 10, 1991: Beech F33A, Sterling, CO, Destroyed, 2 fatal. Struck lake water flying close to surface. Pitched up nosed over impacted water and sand. Demolished on impact.

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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