Pilot Debrief

CIRRUS DESIGN CORP SR22 near Northport, FL — 2009-04-03

Final reportERA09FA228
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Date
2009-04-03
Location
Northport, FL, USA
Aircraft
CIRRUS DESIGN CORP SR22
Registration
N509SR
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

Inadequate torque on one of the No. 6 connecting rod bolt retaining nuts, which resulted in the connecting rod’s separation from the crankshaft and a subsequent total loss of engine power.

NTSB narrative

About 10 minutes after takeoff, when the airplane was in level cruise flight, the engine lost power. The pilot performed a forced landing to a road, which resulted in minor damage to the airplane when the right wing impacted a road sign. An initial examination of the engine revealed a hole in the upper deck in the vicinity of the Nos. 5 and 6 pistons. Further examination revealed that both of the No. 6 connecting rod bolts were fractured. One bolt was missing the self-locking nut, and fretting adjacent to the bolt hole on the split-line face of the connecting rod indicates that the bolt was probably not tightened with sufficient torque and backed off the bolt. The bolt then likely backed out of its hole on the connecting rod, enabling the cap to hinge open, and the loading of the other bolt in tension and bending to the point of overstress. The connecting rod then separated from the crankshaft and punched a hole in the crankcase.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have returned to the airport after noticing oil pressure drop.

NTSB coding

Evidence available

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

Docket documents12

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