# NTSB SEA92LA110: Piper PA-28-140, N6434R, Monarch, MT, May 29, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: May 29, 1992, 12:35 local (18:35 UTC)
- Place: Monarch, MT
- Coordinates: 46.979331, -110.85012 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.9793&lon=-110.8501&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report September 28, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41684
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA92LA110
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41684/pdf
- Page: https://openairdocs.org/ntsb/SEA92LA110

## Probable cause

THE PILOT IN COMMAND'S DISREGARD OF THE WEATHER FORECAST AND FAILURE TO MAINTAIN CLEARANCE WITH TREES/TERRAIN. FACTORS CONTRIBUTING TO THE ACCIDENT WERE:  HILLY/MOUNTAINOUS TERRAIN, WEATHER CONDITIONS: RAIN, LOW CEILINGS AND DOWNDRAFTS, TREES AND THE PILOT IN COMMAND'S CONTINUED FLIGHT INTO KNOWN ADVERSE WEATHER.

## Sequence of events

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

- In flight encounter with weather, cruise
  - weather forecast - disregarded, pilot in command (cause)
- In flight collision with object, cruise
  - terrain condition - mountainous/hilly (contributing factor)
  - weather condition - rain (contributing factor)
  - weather condition - low ceiling (contributing factor)
  - weather condition - downdraft (contributing factor)
  - object - tree(s) (contributing factor)
  - flight into known adverse weather - continued, pilot in command (contributing factor)
  - clearance - not maintained, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

AFTER RECEIVING A WEATHER BRIEFING DURING WHICH VFR FLIGHT WAS NOT RECOMMENDED, THE NON-INSTRUMENT RATED PILOT DEPARTED PRIEST RIVER, EN ROUTE TO LEWISTOWN. APPROXIMATELY 50 NAUTICAL MILES SHORT OF HIS DESTINATION, OVER HILLY/MOUNTAINOUS TERRAIN, THE AIRCRAFT COLLIDED WITH TREES NEAR THE TOP OF A 7650 FOOT RIDGELINE AND CRASHED. THE PILOT REPORTED LOW CEILINGS AND 1.5 MILES VISIBILITY RESTRICTED BY MODERATE RAIN AND CLOUDS AT THE TIME OF THE ACCIDENT. HE ALSO REPORTED A LOSS OF ALTITUDE AT FULL POWER APPROACHING THE RIDGELINE THAT WAS NOT ATTRIBUTED TO ANY AIRCRAFT MALFUNCTION.

## Aircraft

- Registration: [N6434R](https://openairdocs.org/deregistered/N6434R-2003-05-02), registration cancelled 2003-05-02, S/N 28-21615, built 1966 (OpenAirDocs)
- Reported make and model: PIPER PA-28-140
- Registry model: [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140) (registry code 7102802) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 28-21615
- Airframe hours: 2662
- Engines: LYCOMING O-320-E2A 150 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Chamberlain, Dwight N.
- Registered owner: Chamberlain, Dwight N.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 1, 1991, 53 hours before
- Departed: 1S6, PRIEST RIVER, ID
- Destination: LWT, LEWISTOWN, MT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 263 total, 198 in this make and model, 256 as pilot in command, 36 in the last 90 days, 12 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 240° at 6 knots
- Visibility: 45 statute miles
- Lowest ceiling: 4,500 ft broken
- Temperature: 54 °F, dew point 50 °F
- Altimeter: 29.00 inHg
- Observed at: GTF, 38 nm away

## 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 19920529017259A](https://openairdocs.org/incident/19920529017259A), May 29, 1992: Piper PA28140, Monarch, MT, Destroyed. Flying in a pass between overcast and rising terrain encouctered downdraft. Crashed into trees. VFR not recommended

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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