# NTSB DEN92LA033: Cessna 172N, N737BY, Parshall, CO, February 10, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 10, 1992, 16:15 local (23:15 UTC)
- Place: Parshall, CO
- Coordinates: 40.049468, -106.179122 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.0495&lon=-106.1791&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report June 30, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18197
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN92LA033
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18197/pdf
- Page: https://openairdocs.org/ntsb/DEN92LA033

## Probable cause

IMPROPER USE OF POWERPLANT CONTROLS BY THE DUEL STUDENT AND INADEQUATE SUPERVISION BY THE CFI. FACTORS WERE: CARBURETOR HEAT NOT USED, DEEP SNOW COVERED TERRAIN, AND CARBURETOR ICE CONDITIONS.

## Analysis

THE STUDENT PILOT DESCENDED 1000 FEET AND MADE A PRACTICE FLARE FOR LANDING OVER SNOW COVERED TERRAIN.  WHEN THE THROTTLE WAS OPENED, THE ENGINE SPUTTERED.  THE INSTRUCTOR SAID THEY DID NOT USE CARBURETOR HEAT BUT THE MIXTURE HAD BEEN LEANED.  ADDITIONALLY, NEITHER STUDENT NOR INSTRUCTOR 'CLEARED THE ENGINE' DURING THE DESCENT.  THE INSTRUCTOR SURMISED THE ENGINE HAD 'LOADED UP.'  THE NOSE GEAR COLLAPSED IN THE DEEP SNOW.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, landing - flare/touchdown
  - weather condition - carburetor icing conditions (contributing factor)
  - powerplant controls - improper use of, dual student (cause)
  - carburetor heat - not used, dual student (contributing factor)
  - supervision - inadequate, pilot in command(cfi) (contributing factor)
- Nose gear collapsed, landing - roll
  - terrain condition - snow covered (contributing factor)

## Aircraft

- Registration: [N737BY](https://openairdocs.org/deregistered/N737BY-2012-10-09), registration cancelled 2012-10-09, S/N 17269302 (OpenAirDocs)
- Reported make and model: CESSNA 172N
- Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs)
- Category: Airplane
- Serial number: 17269302
- Airframe hours: 3932
- Engines: LYCOMING O-320-YHH2AD 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Jsc Aircraft Service
- Registered owner: John D. Burrington
- Airworthiness certificate: Standard, Normal; Standard, Utility
- Last inspection: 100 hour, December 9, 1991, 50 hours before
- Departed: 20V, KREMMLING, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 406 total, 315 in this make and model, 272 as pilot in command, 61 in the last 90 days, 29 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 100° at 5 knots
- Visibility: 25 statute miles
- Lowest ceiling: 6,000 ft broken
- Temperature: 32 °F, dew point 23 °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 19920210014209A](https://openairdocs.org/incident/19920210014209A), Feb 10, 1992: Cessna 172N, Parshall, CO, Substantial damage. Practicing descent to flare over frozen snow covered reservoir. Engine failed respond. Landed in deep snow.

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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