Pilot Debrief

BELLANCA 17 30A near Blaine, MN — 2016-12-18

Final reportCEN17LA058
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Date
2016-12-18
Location
Blaine, MN, USA
Aircraft
BELLANCA 17 30A
Registration
N4204B
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

A total loss of engine power due to a lack of crankshaft lubrication to the No. 4 connecting rod journal.

NTSB narrative

After dropping off two passengers on an extremely cold morning, the commercial pilot departed for the return flight home. During cruise flight at 2,500 ft mean sea level, the engine experienced a total loss of power. The pilot restarted the engine; shortly thereafter, the engine lost power a second time. The pilot executed a forced landing onto a road, during which the left wing was damaged. An engine teardown revealed significant heat distress to the crankshaft No. 4 connecting rod journal, as well as the Nos. 3 and 4 connecting rod bearings. The heat distress resulted in fracture of the Nos. 3 and 4 connecting rod caps and subsequent seizure of the engine. The Nos. 1, 2, 5, and 6 connecting rod bearings exhibited overlay fatigue, dirt embedment and corrosion, consistent with inadequate oil lubrication. A review of the engine maintenance logbooks revealed a history of oil changes at inconsistent intervals, which included much longer intervals than those recommended by the manufacturer; however, the effect of the inconsistent maintenance could not be determined based on the available information.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have checked oil levels and engine condition before departure from HIB.

NTSB coding

Evidence available

  • 4 docket documents
View NTSB final reportView NTSB docket

Docket documents4

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