Pilot Debrief

CIRRUS DESIGN CORP SR22 near Dixon, CA — 2017-06-30

Final reportWPR17LA137
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Date
2017-06-30
Location
Dixon, CA, USA
Aircraft
CIRRUS DESIGN CORP SR22
Registration
N744TC
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Descent

Probable cause

A total loss of engine power for reasons that could not be determined due to extensive damage.

NTSB narrative

The pilot reported that, after he leveled off for the personal cross-country flight, he leaned the engine for cruise flight. The pilot noticed that the manifold pressure was lower than usual although the engine instruments indicated “in the green.” About 30 minutes later, the oil pressure reading rapidly dropped; the engine subsequently lost all power and made a loud bang, then oil sprayed on the wind screen, which impeded the pilot’s visibility. The pilot deployed the Cirrus Airframe Parachute System and the airplane descended into a vineyard. A main landing gear went through and substantially damaged the wing. Visual examination of the engine revealed a hole in the top of the engine case. A piece of connecting rod and connecting rod bolt was found on top of the left side baffling. Disassembly of the engine revealed that the numbers 3 and 4 connecting rods were fractured and separated from their connecting rod journals. Thermal discoloration to the connecting rod journals was consistent with oil starvation. The crankcase had fractured. Postaccident examination of the turbochargers revealed that the left turbocharger was functional. The right turbine was damaged, and its wheel head had separated from the turbine shaft and was not located. The right turbine shaft fractured circumferentially at a piston ring groove, but the type of fracture could not be determined due to the extensive damage. Postaccident examination did not show any evidence of preimpact mechanical malfunction or abnormalities that would have precluded normal operation. However, the extent of internal damage to the engine components during impact/the accident sequence and the missing right turbine wheel head precluded a detailed examination of the engine.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Proper inspection of the turbocharger assembly could have prevented engine failure.

NTSB coding

Evidence available

  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

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