# NTSB SEA92LA072: Piper PA-23-160, N3494P, Missoula, MT, April 10, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 10, 1992, 15:59 local (21:59 UTC)
- Place: Missoula, MT
- Coordinates: 46.850719, -113.989509 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.8507&lon=-113.9895&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report June 30, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41653
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA92LA072
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41653/pdf
- Page: https://openairdocs.org/ntsb/SEA92LA072

## Probable cause

PARTIAL BLOCKAGE OF THE LEFT ENGINE INDUCTION AIR FILTER, INABILITY TO MAINTAIN THE PROPER RATE OF DESCENT, AND DELAYED EXTENSION OF THE LANDING GEAR.  FACTORS CONTRIBUTING TO THE ACCIDENT WERE ICING CONDITIONS, WING ICE, AND ROUGH/UNEVEN TERRAIN.

## Sequence of events

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

- Loss of engine power(partial) - nonmechanical, cruise
  - 1 engine
  - induction air control,air filter/screen - blocked(partial) (cause)
  - weather condition - icing conditions (contributing factor)
- Forced landing, descent - emergency
  - wing - ice (contributing factor)
  - proper descent rate - not possible (cause)
- Nose gear collapsed, landing - roll
  - terrain condition - rough/uneven (contributing factor)
  - gear extension - delayed, pilot in command (cause)

## Analysis

THE PILOT AND PILOT RATED PASSENGER (RIGHT SEAT) DEPARTED IN THE PA-23 AND CLIMBED TO 11000 FEET ON A LOCAL ROUND ROBIN FLIGHT. THE AIRCRAFT WAS NOT EQUIPPED WITH WING OR PROPELLER DEICE/ANTI ICE SYSTEMS. MISSOULA REPORTED SEVERAL SCATTERED, BROKEN AND OVERCAST CLOUD LAYERS BELOW 11000 FEET DURING THE AFTERNOON AND THE SURFACE TEMP PEAKED AT 44 DEGREES F. AT 11000 FEET THE PILOTS ENCOUNTERED A VIBRATION AND LOSS OF LEFT ENGINE POWER AND INITIATED A RETURN TO MISSOULA FOR LANDING. UNABLE TO MAINTAIN ALTITUDE WITH PARTIAL POWER A FORCED LANDING WAS EXECUTED SHORT OF RUNWAY 25 AT THE MISSOULA AIRPORT. ALTHOUGH AN ATTEMPT WAS MADE TO LOWER THE LANDING GEAR PRIOR TO THE FORCED LANDING THE NOSE LANDING GEAR COLLAPSED DURING ROLLOUT WHEN IT STRUCK A GOPHER HOLE. AIRPORT ARFF PERSONNEL OBSERVED ICE DETACHING FROM THE AIRCRAFT WING(S) FOLLOWING THE ACCIDENT AND FAA PERSONNEL INSPECTING THE AIRCRAFT SUBSEQUENT TO THE ACCIDENT REPORTED THAT THE LEFT INDUCTION AIR FILTER WAS HEAVILY SOAKED WITH WATER.

## Aircraft

- Registration: [N3494P](https://openairdocs.org/deregistered/N3494P-2013-09-27), registration cancelled 2013-09-27, S/N 23-1470, built 1958 (OpenAirDocs)
- Reported make and model: PIPER PA-23-160
- Registry model: [Piper PA-23-160](https://openairdocs.org/model/piper-pa-23-160) (registry code 7102304) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 23-1470
- Airframe hours: 5312
- Engines: LYCOMING O-320-B3B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Pearson, Erik & Crow, Charles
- Registered owner: Pearson, Erik & Crow, Charles
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 15, 1991, 227 hours before
- Departed: 32S, STEVENSVILLE, MT
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 23; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 752 total, 250 in this make and model, 620 as pilot in command, 249 in the last 90 days, 124 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 15 statute miles
- Lowest ceiling: 3,200 ft overcast
- Temperature: 45 °F, dew point 39 °F
- Altimeter: 29.00 inHg
- Observed at: MSO, 1 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 19920410012129A](https://openairdocs.org/incident/19920410012129A), Apr 10, 1992: Piper PA23160, Missoula, MT, Substantial damage. Lost partial power left engine. Landed short in field, hit gopher mound. Nose gear collasped.

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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