# NTSB DEN90LA075: Cessna 172, N61918, Elkhorn, MT, March 18, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 18, 1990, 12:47 local (19:47 UTC)
- Place: Elkhorn, MT
- Coordinates: 46.170669, -111.990455 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.1707&lon=-111.9905&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report September 15, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 17904
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN90LA075
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17904/pdf
- Page: https://openairdocs.org/ntsb/DEN90LA075

## Probable cause

THE PILOT'S DECISION TO ATTEMPT FLIGHT IN TERRAIN AND CONDITIONS WHICH EXCEEDED THE PERFORMANCE CAPABILITIES OF THE AIRPLANE.

## Sequence of events

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

- Loss of control - in flight, cruise
  - weather condition - downdraft
  - in-flight planning/decision - improper, pilot in command (cause)
  - overconfidence in aircraft's ability, pilot in command
  - terrain condition - blind/box canyon
  - aircraft performance,climb capability - exceeded (cause)
- Forced landing, descent - uncontrolled
- In flight collision with object, descent - uncontrolled
  - object - tree(s)

## Analysis

THE FLIGHT FLEW LOW AND SLOW UP A STEEP CANYON. THE PILOT SAID THE FLIGHT ENCOUNTERED A STRONG DOWNDRIFT AND COULD NOT MAINTAIN ALTITUDE WITH FULL POWER APPLIED. THE PILOT SAID THE CANYON WALLS CLIMBED STEEPLY AND NARROWED RAPIDLY, PREVENTING HIM FROM TURNING BACK OUT OF THE CANYON. THE PLANE NOSED DOWN INTO THE TREES, WEDGED AGAINST A TREE TRUNK, AND CAME TO REST 8 FEET OFF THE GROUND IN A NOSE DOWN ATTITUDE. THE PILOT SAID THE RIGHT WING, FUSELAGE AND THE PROPELLER WERE BENT. THE PILOT SAID HE SHOULD HAVE SELECTED A HIGHER ALTITUDE AND NOT FLOWN UP THE CANYON.

## Aircraft

- Registration: [N61918](https://openairdocs.org/deregistered/N61918-2013-02-11), registration cancelled 2013-02-11, S/N 17264884, built 1975 (OpenAirDocs)
- Reported make and model: CESSNA 172
- Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17264884
- Engines: LYCOMING O-320-E2D 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Helena Aircraft Inc.
- Registered owner: Unknown
- Departed: HLN, HELENA, MT
- Destination: HLN
- Airport: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; flight hours: 550 total, 472 in this make and model, 420 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 5 knots
- Visibility: 20 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 19900318004689A](https://openairdocs.org/incident/19900318004689A), Mar 18, 1990: Cessna 172M, Elkhorn, MT, Substantial damage. Flew into box canyon too low and slow. Encountered downdraft,unable to clear rising terrain or turn, struck trees.

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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