Pilot Debrief

CIRRUS DESIGN CORP SR22 near Lexington, NC — 2014-10-22

Final reportERA15IA024
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Date
2014-10-22
Location
Lexington, NC, USA
Aircraft
CIRRUS DESIGN CORP SR22
Registration
N242MB
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

Maintenance personnel's improper tightening of the crankcase through bolt nuts during reassembly of the engine at the last overhaul, which resulted in the failure of the crankshaft and the subsequent total loss of engine power.

NTSB narrative

The commercial pilot was conducting a personal cross-country flight. The pilot reported that, while en route to his destination at a cruise altitude of about 5,000 ft mean sea level, the engine "failed." He flew the airplane toward an open field and deployed the ballistic recovery parachute. He subsequently conducted a successful landing in the field. An examination of the engine revealed that the crankshaft had fractured between the No. 2 main journal and the No. 2 connecting rod journal. An examination of the crankshaft revealed that the fracture was due to fatigue that had initiated from multiple origins at the fillet radius between the No. 2 main journal and the cheek at the aft end of the journal. The fatigue initiated from surface damage that occurred due to the No. 2 main bearing shifting. The bearing likely shifted due to the improper tightening of the crankcase through bolt nuts and subsequent insufficient clamping force of the crankcase saddle surfaces. A review of the airplane's maintenance records revealed that the engine was last overhauled 775 total flight hours before the accident, and no records were found indicating that the through bolts had been removed since that time. It is likely that maintenance personnel improperly tightened the crankcase through bolts during the overhaul.

Analysis

Primary failure mode
Engine power loss

NTSB coding

  • Loss of engine power (total) · Enroute-cruise
  • Engine Failure Enroute
  • Maintenance

Evidence available

  • Photos
  • 9 docket documents
View NTSB final reportView NTSB docket

Docket documents9

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