# NTSB ANC86IA066: Cessna 207, N1737U, Manokotak, AK, June 6, 1986

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: June 6, 1986, 13:15 local (21:15 UTC)
- Place: Manokotak, AK
- Coordinates: 58.880493, -158.930007 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=58.8805&lon=-158.9300&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 6 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4613
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC86IA066
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4613/pdf
- Page: https://openairdocs.org/ntsb/ANC86IA066

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise
  - engine assembly,crankshaft - failure,total (cause)
- Forced landing, descent - emergency

## Analysis

DURING CRUISE FLIGHT THE ENGINE BEGAN TO RUN ROUGH. THE PILOT ATTEMPTED SWITCHING FUEL TANKS BUT THE ENGINE CONTINUED TO RUN ROUGH. THE ENGINE CEASED OPERATION AND DID NOT WINDMILL DURING THE EMERGENCY DESCENT. AN EXAMINATION OF THE ENGINE LATER REVEALED THAT THE CRANKSHAFT HAD FRACTURED IN THE VICINITY OF THE NUMBER 2 AND 3 CRANKSHAFT JOURNAL. THE MODE OF FRACTURE WAS NOT DETERMINED. AN OFF ARPT FORCED LNDG WAS ACCOMPLISHED WITHOUT FURTHER INCIDENT.

## Aircraft

- Registration: N1737U (not matched to a registry record)
- Reported make and model: CESSNA 207
- Category: Airplane
- Serial number: 20700307
- Airframe hours: 3800
- Engines: CONTINENTAL 10-520-F 300 horsepower reciprocating
- Damage: Minor damage
- Flight: Part 135
- Registered owner: Phillip L. Bingman
- Last inspection: 100 hour, June 3, 1986, 20 hours before
- Departed: 175Z, MANOKOTAK, AK
- Destination: DLG, DILLINGHAM, AK
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 5,810 total, 300 in this make and model, 6,300 as pilot in command, 75 in the last 90 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 10 knots, gusting 21
- Visibility: 25 statute miles
- Lowest ceiling: 12,000 ft broken
- Temperature: 50 °F, dew point 34 °F
- Altimeter: 29.00 inHg

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19860606054349I](https://openairdocs.org/incident/19860606054349I), Jun 6, 1986: Cessna T207, Manokotak, AK, Minor damage. Engine became rough en route and froze up. Landed in the tundra. Massive internal engine failure. Broken crankshaft

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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