# NTSB DEN90LA082: Piper PA-18-150, N7134K, Whitewater, MT, March 28, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 28, 1990, 07:20 local (14:20 UTC)
- Place: Whitewater, MT
- Coordinates: 48.780475, -107.510543 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.7805&lon=-107.5105&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report September 15, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 17910
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN90LA082
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17910/pdf
- Page: https://openairdocs.org/ntsb/DEN90LA082

## Probable cause

PILOT'S DELAYED USE OF CARBURETOR HEAT AND THE SUBSEQUENT INDUCTION ICING RELATED PARTIAL POWER LOSS. CONTRIBUTING FACTORS WERE THE CARBURETOR ICING CONDITIONS AND THE UNSUITABLE TERRAIN IN WHICH THE FORCED LANDING WAS PERFORMED.

## Sequence of events

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

- Loss of engine power, cruise
  - 1 engine
  - induction air control/system - ice (cause)
  - carburetor heat - delayed, pilot in command (cause)
  - induction air control/system - blocked(partial)
  - weather condition - carburetor icing conditions (contributing factor)
  - flight into known adverse weather - continued, pilot in command (contributing factor)
- Forced landing, descent - emergency
  - terrain condition - none suitable (contributing factor)
- On ground/water encounter with terrain/water, landing - flare/touchdown
- Nose over, landing - roll

## Analysis

THE PRIVATE PILOT ENCOUNTERED FREEZING FOG AND HAZE, REDUUCING THE VISIBILITY TO THREE MILES. HE TURNED BACK TO LAND BUT THE ENGINE BEGAN TO RUN ROUGH. HE ADDED CARBURETOR HEAT BUT THE ENGINE BECAME ROUGHER AND REDUCED TO PARTIAL POWER. THE PILOT SELECTED A RIDGE IN ROUGH TERRAIN AND MADE A FORCED LANDING. AT TOUCHDOWN, THE TAIL LIFTED AND THE PLANE NOSED OVER. THE VERTICAL STABILIZER, ELEVATOR, WINGS, COWLING AND FIREWALL WERE BENT. DURING A POSTACCIDENT ENGINE RUN THE ENGINE OPERATED NORMALLY AND RAN FOR FIVE MINUTES.

## Aircraft

- Registration: [N7134K](https://openairdocs.org/aircraft/N7134K), registered now, S/N 18-352, built 1950 (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- Registry model: [Piper PA-18 105](https://openairdocs.org/model/piper-pa-18-105) (registry code 7101809) (OpenAirDocs)
- Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-352
- Engines: LYCOMING O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Clinton Cox
- Departed: NONE
- Destination: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; flight hours: 480 total, 480 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 3 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 19900328011339A](https://openairdocs.org/incident/19900328011339A), Mar 28, 1990: Piper PA18105, Whitewater, MT, Substantial damage. Weather worsened flying to a ranch, turned back, engine quit. Nosed over landing. No defects, possible carb icing.

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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