Pilot Debrief

CESSNA P210N near Bryan, TX — 2016-02-16

Final reportCEN16LA107
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Date
2016-02-16
Location
Bryan, TX, USA
Aircraft
CESSNA P210N
Registration
N732FU
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Climb

Probable cause

A failure of the crankshaft due to improper torque of the crankcase through bolts.

NTSB narrative

The private pilot reported that, 10 miles from the destination airport, the passengers heard a loud "clank" and smoke entered the cockpit. Shortly thereafter, the engine experienced a total loss of power and the propeller stopped turning. The pilot selected a field as a forced landing site, but the airplane impacted trees and terrain at the edge of the field. The pilot and passengers were able to extricate themselves through the right side passenger window. A postaccident engine examination revealed a catastrophic failure of the engine crankshaft between the No. 2 main bearing journal and the No. 2 connecting rod journal. The damage displayed on the No. 2 bearing was consistent with the bearing having shifted and spun. Several of the bearing supports displayed fretting near the through-bolt holes. An accurate measurement of the preaccident through-bolt torques could not be determined due to the loads subjected upon the crankcase when the crankshaft failed. Review of maintenance records indicated that the through bolts were properly torqued during the remanufacturing process nearly 1,000 flight hours before the accident and that there was no record of major work performed on the engine since that time; however, the wear signatures displayed on the bearing supports indicated that the crankcase halves were shifting in a manner consistent with improper torque of the through bolts.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have performed an emergency landing sooner after engine power loss.

NTSB coding

Evidence available

  • 9 docket documents
View NTSB final reportView NTSB docket

Docket documents9

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