Cessna U206F N35831

Summary

On 19 August 1991 at about 04:30 local time, a Cessna U206F registered N35831, operated by Evergreen Helicopters, was involved in an accident near Nimrod, Oregon, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 August 1991 at 04:30

Classification

Accident

Location

Nimrod, Oregon, United States

Coordinates

44.1295, -122.4196

Aircraft

Cessna U206F

Registration

N35831

Category

Airplane

Engines

1

Operator

Evergreen Helicopters

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Crescent Lake → McMinnville

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

SEA91LA212

Nobody was injured.

THE FRACTURED CRANKSHAFT RESULTING IN ENGINE SEIZURE FOLLOWED BY A FORCED LANDING ON ROUGH AND UNEVEN TERRAIN RESULTING IN SEPARATION OF THE NOSE GEAR.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

WHILE IN CRUISE FLIGHT THE ENGINE BEGAN RUNNING ROUGH AND ULTIMATELY SEIZED. THE PILOT EXECUTED A FORCED LANDING DURING DARK NIGHT CONDITIONS ONTO ROUGH AND UNEVEN TERRAIN WITHIN A LOGGING CLEARCUT AREA. DURING THE ROLLOUT THE NOSE GEAR WAS SHEARED OFF AND THE AIRCRAFT NOSED OVER TO AN INVERTED POSITION RESULTING IN SUBSTANTIAL DAMAGE. SUBSEQUENT DISASSEMBLY OF THE ENGINE REVEALED A FATIGUE CRACK WHICH GENERATED INTO A FRACTURE OF THE CRANKSHAFT. THE CRACK WAS OBSERVED TO EMANATE FROM THE OIL TUBE PASSAGE HOLE IN THE NUMBER FOUR SHORT CHEEK OF THE CRANKSHAFT.

Quoted verbatim from the NTSB record.