A BEECH DUCHESS 76 INCURRED PROP DAMAGE ON ENG START WHEN A NON STANDARD TOOL WAS USED TO FASTEN THE COWLING SLIPPED OUT INTO THE PROP.

Narrative

A BUCKING BAR WAS INADVERTENTLY LEFT IN THE ENG COMPARTMENT; FOLLOWING ROUTINE MAINT TO REPLACE A STARTER. UPON SHUTDOWN OF THE L ENG THE BUCKING BAR FELL OUT OF THE ENG COMPARTMENT; STRIKING THE PROP. NO OTHER DAMAGE WAS FOUND. THE BAR; 5/16 INCHES X 2 INCHES X 1.5 FT WAS USED TO HOLD DOWN THE BAFFLING; WHILE INSTALLING THE COWLING. NORMALLY A RED RAG IS PLACED UNDER THE BAR AND DRAPED OUT THE FRONT OF THE ENG; BUT NO RED RAGS WERE AVAILABLE. WITHOUT THE RAG IT WAS DIFFICULT TO DETECT (SEE) THE BAR; AND WAS THEREFORE NOT REMOVED PRIOR TO STARTING THE ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THE BAR; A NON STANDARD TOOL WITH A RED RAG ATTACHED; IS USED TO HOLD DOWN THE AIR BAFFLES WHEN INSTALLING THE COWLING AND IS PULLED OUT WHEN THE COWLING IS FASTENED BUT THE RED RAG WAS OMITTED AND THE RPTR MISSED REMOVING THE BAR. THE RPTR STATED WHEN THE ENG WAS STARTED THE BAR SLIPPED OUT INTO THE PROP ARC AND BANGED AROUND IN THE PROP FOR A FEW MOMENTS. THE RPTR SAID WHEN THE PROP BLADES WERE CHKED 2 OF THE 3 BLADES HAD TO BE REPLACED AND THE DAMAGED BLADES HAD EVIDENCE OF STRIKING THE BAR AT LEAST 20 TIMES. THE RPTR STATED A SPECIAL TOOL HAS BEEN FABRICATED WITH A LARGE RED FLAG TO BE USED IN COWLING REPLACEMENT.