# NTSB CHI85LA260: Stinson 108-1, N9070K, Roseau, MN, June 20, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 19, 1985, 20:15 local (Jun 20, 1985, 01:15 UTC)
- Place: Roseau, MN
- Coordinates: 48.839733, -95.760765 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.8397&lon=-95.7608&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 13115
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI85LA260
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13115/pdf
- Page: https://openairdocs.org/ntsb/CHI85LA260

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, descent - normal
  - weather condition - carburetor icing conditions (contributing factor)
  - in-flight planning/decision - improper, pilot in command (cause)
  - fuel system,carburetor - ice
- Forced landing, descent - emergency
- Complete gear collapsed, landing - roll
  - ground loop/swerve - intentional, pilot in command

## Analysis

THE PLT INTENTIONALLY GROUND LOOPED THE ACFT DURING A FORCED LANDING TO AVOID OBSTACLES FOLLOWING A LOSS OF POWER EN ROUTE. APRX 1 1/2 HRS INTO THE FLT THE PLT NOTICED AN ENGINE ROUGHNESS FOLLOWED BY AN INCREASE IN OIL TEMP WHICH RETURNED TO NORMAL SHORTLY THEREAFTER. ABOUT 1 HR LATER, A 25 RPM DECREASE AND ENGINE ROUGHNESS WAS EXPERIENCED. A CONTINUED DECREASE IN RPM WAS EXPERIENCED THROUGHOUT THE NEXT 1/2 HR AND THE PLT LEANED THE MIXTURE AND TURNED THE CARB HEAT ON AND OFF IN AN ATTEMPT TO REGAIN POWER. A TOTAL LOSS OF POWER WAS THEN EXPERIENCED AND THE FORCED LANDING WAS INITIATED. AN ICING PROBABILITY CHART INDICATES THE EXISTING TEMP (70 DEGS F) AND THE DEW POINT (55 DEGS F) WHERE CONDUCIVE TO CARB ICE. NO MECHANICAL FAILURE/MALFUNCTION WAS FOUND.

## Aircraft

- Registration: [N9070K](https://openairdocs.org/aircraft/N9070K), registered now, S/N 108-2070, built 1947 (OpenAirDocs)
- Reported make and model: STINSON 108-1
- Registry model: [Stinson 108](https://openairdocs.org/model/stinson-108) (registry code 9230402) (OpenAirDocs)
- Registry engine: [Franklin 6A4150 series](https://openairdocs.org/engine/franklin-6a4150-series) (registry code 27024, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 2070
- Airframe hours: 2704
- Engines: FRANKLIN 150 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Ronald C. Mosman
- Airworthiness certificate: Standard, Normal
- Departed: ANE, BLAINE, MN
- Destination: ROX, ROSEAU, MN

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,574 total, 1,458 in this make and model, 1,525 as pilot in command, 25 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 70 °F, dew point 55 °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 19850619031419A](https://openairdocs.org/incident/19850619031419A), Jun 19, 1985: Univar 108, Roseau, MN, Substantial damage. Power loss in flight due to probable carburetor icing. Ground looped aircraft to avoid obstacle in field.

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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