# NTSB DEN89FA200: Cessna 172, N4129F, Tremonton, UT, August 27, 1989

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Field investigation · Final report
- Date: August 27, 1989, 16:15 local (22:15 UTC)
- Place: Tremonton, UT
- Coordinates: 41.690471, -112.269241 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.6905&lon=-112.2692&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report July 9, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 17604
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89FA200
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17604/pdf
- Page: https://openairdocs.org/ntsb/DEN89FA200

## Probable cause

THE PILOT FAILED TO MAINTAIN OBSTRUCTION CLEARANCE WHILE MAKING A LOW PASS OVER A NEWLY CONSTRUCTED HIGHWAY.  THE POWERLINE WAS CONSIDERED A CONTRIBUTING FACTOR.

## Sequence of events

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

- In flight collision with object, maneuvering
  - low pass - performed, pilot in command (cause)
  - object - wire,transmission
  - clearance - not maintained, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT WAS MAKING A LOW PASS OVER A NEWLY CONSTRUCTED INTERSTATE HIGHWAY, WHEN THE AIRPLANE STRUCK AN UNMARKED POWER LINE. AFTER HITTING THE POWER LINE, A LARGE PORTION OF THE VERTICAL STABILIZER AND RUDDER SEPARATED FROM THE AIRPLANE. THE AIRPLANE THEN CRASHED IN AN OPEN FIELD APPROXIMATELY 1500 FEET BEYOND THE POWER LINE.

## Aircraft

- Registration: [N4129F](https://openairdocs.org/deregistered/N4129F-2012-06-07), registration cancelled 2012-06-07, S/N 46029, built 1958 (OpenAirDocs)
- Reported make and model: CESSNA 172
- Registry model: [Cessna 172](https://openairdocs.org/model/cessna-172) (registry code 2072402) (OpenAirDocs)
- Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 46029
- Airframe hours: 4488
- Engines: LYCOMING O-300-A 145 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Pleasure Air, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 9, 1989, 125 hours before
- Departed: U27, TREMONTON, UT
- Destination: U27

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 170 total, 40 in this make and model, 121 as pilot in command, 23 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 170° at 5 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 81 °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 19890827031769A](https://openairdocs.org/incident/19890827031769A), Aug 27, 1989: Cessna STC172, Tremonton, UT, Substantial damage. Vertical stabilizer struck powerline over a freeway. Impact severed fin and rudder. Crashed observing construction.

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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