Aviation safety investigations & reports

Piper Aircraft Corp PA-31-350, VH-JCH

Investigation number:
200105866
Status: Completed
Investigation completed

Summary

The PA31-350 aircraft was in cruise flight, at 8,000 ft, when the flight crew noticed that the propellers went out of synchronisation. Adjustments were made to correct the problem but were unsuccessful. Following right engine RPM fluctuations, the crew shut the engine down, feathered the propeller and conducted a single engine landing.

During the subsequent disassembly of the engine, the crankshaft was noted to have fractured at the number-6 connecting rod journal.

The engine components were sent to the ATSB for further technical analysis. Analysis of the fracture indicated that fatigue cracking had initiated below the surface of the journal, associated with a discontinuity in the nitrided surface zone, at the transition from the journal to the forward fillet radius. The number-6 connecting rod bearing inserts had been destroyed during operation; the remnants included flattened fragments of steel backing material. In addition, fatigue crack growth had commenced at the centre of the connecting rod cap, most probably after the bearing inserts had failed.

Because of the small amount of bearing debris available for testing, the reason the number-6 bearing inserts failed could not be determined.

This engine failure is one of a number of events being used in a detailed safety study of failures to high powered piston engines. On completion, the results will be available on the ATSB website www.atsb.gov.au or from the Bureau on request.

General details
Date: 14 December 2001   Investigation status: Completed  
Time: 1650 hours ESuT    
Location   (show map): 83 km NE Warrnambool, Aero.    
State: Victoria    
Release date: 18 July 2002    
Report status: Final   Occurrence category: Incident  
  Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Piper Aircraft Corp  
Aircraft model PA-31  
Aircraft registration VH-JCH  
Serial number 31-8152106  
Type of operation Air Transport Low Capacity  
Damage to aircraft Nil  
Departure point Avalon, VIC  
Departure time 1624 hours ESuT  
Destination Portland, VIC  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command ATPL 2800 3845
Co-Pilot/1st Officer Commercial 173.6 444
Last update 13 May 2014