Engines

AVCO LYCOMING, IO-540-AE1A5
Service Difficulty Report (SDR) # 20110317003
 
Connecting Rod Failure

SDR submitted:

The pilot reported a loud bang and subsequent engine failure. The pilot auto-rotated to an open field with no damage to the airframe during the landing. The aeroplane was removed from the field and transported to a repair facility for further investigation. Aeroplane panels were removed and a large hole in the crankcase was observed near the #3 cylinder intake lifter bore. Large pieces of crankcase debris were found on top of the engine case above the #2 cylinder area. Lycoming was advised and a field service rep came to investigate the failure on location.

Initial indications were the #4 connecting rod failed just below the piston pin area and this caused the breach in the crankcase between the #3 & #4 cylinders.

Transport Canada Comments:
The cause of this connecting rod failure was the result of a missing wrist Pin Plug. Maintainers are reminded that all manufacturers’ instructions must be followed. 

A crankcase damaged from a failed connecting rod

AVCO LYCOMING, IO-360-B1B
SDR # 20110322008
 
Incorrect Fuel Pump Fitting

SDR submitted:

The engine was received fresh from the overhaul facility with the engine driven fuel pump and associated fittings assembled. Post install ground runs were unable to achieve take off power. After 2300 revolutions per minute (rpm) further power lever advancement resulted in loss of revolutions per minute (rpm) and increase in manifold pressure, indicating fuel starvation. Upon inspection it was found that the inlet fitting to the fuel pump was restricted (just a pin hole) either the part was not manufactured properly (not fully drilled through) or it is an incorrect part (a restrictor fitting). In either case it does not belong on the engine. The fitting was replaced with the correct part and engine runs completed.

Transport Canada Comments:
Inventory control is of utmost importance. When receiving parts from stock or from a supplier, it is important to inspect for defects and that the part ordered is the part received.

An incorrect fuel pump fitting | A correct fuel pump fitting

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Incorrect fitting
Correct fitting

AVCO LYCOMING, O-320-D2J
SDR # 20110329006
 
Sudden Engine Stoppage

SDR submitted:

The engine experienced a sudden stoppage in flight. Aircraft was landed and the engine was removed and shipped for inspection. Upon disassembly, it was found that the #4 cylinder failed due to a crack that progressed from near the top of the barrel almost all the way around the circumference. This failure seized the engine. This cylinder appears to be a field overhauled unit and has been sent to Transport Safety Board (TSB) for inspection. The last engine logbook entry has 488.9 hours since overhaul. The engine was last overhauled June 19, 2009 and was installed October 23, 2009.

Transport Canada Comments:
It is likely that this crack was almost undetectable using visual inspection technique before the catastrophic failure. Field overhauls must be completed in accordance with the manufacturer’s instruction and include any required Non-Destructive inspections carried out by an appropriately rated facility.

A cracked #4 cylinder

PRATT & WHITNEY, PT6 A-67R
SDR # 20110525010
 
Power Turbine Failure

SDR submitted:

The engine was removed subsequent to a catastrophic failure during takeoff role. The pilot reported, “engine failed on takeoff roll, audible noise, metal exiting exhaust duct, engine went to minimum flow and takeoff aborted”.

During a dismantle investigation, the power section was found excessively damaged and it appeared that the failure occurred in the power turbine area. The 1st stage power turbine blades were found broken close to the platform areas. The fracture surface exhibited rough appearance with textures of brittle overloading fracture. The 2nd stage power turbine blades were found broken; the breakage varying from below shrouded the blade tip to above the blade platform.

Service Bulletin (SB) 14369 was released to address a premature failure issue and Service Bulletin (SB) 14003 provides relevant life limit recommendations for pre-service bulletin 14369 2nd stage power turbine blades.

A broken 1st stage Power Turbin blade

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Overload area
Fatigue area

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