A VANS RV-4 ON CLBOUT AT 7000 FT SHUTDOWN THE ENG DUE TO A LOUD BANG AND SEVERE VIBRATION CAUSED BY A FAILED PROPELLER BLADE.

Narrative

ON TUE/JAN/03 AT ABOUT XA:35 LOCAL I HAD DEPARTED ZZZ ARPT AND WAS JUST ABOUT TO LEVEL OFF FOR CRUISE. I HEARD A BANG ALMOST LIKE A SHOT GUN NOISE AND THEN ACFT VIBRATION. I SHUT DOWN THE ENG AND TURNED BACK TO ZZZ ARPT. I LANDED THE ACFT NO PROB. THE PROPELLER I WAS FLYING WAS A MODEL F-200 AUTOMATIC VARIABLE PITCH PROPELLER. THIS WAS MY SECOND FLT WITH THE PROPELLER. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PROPELLER WAS A VARIABLE PITCH PROPELLER AND HAD COMPLETED ONE FLT AND WAS ON THE SECOND FLT WHEN IT FAILED. THE RPTR SAID THE PROPELLER IS MADE OF WOOD ENCAPSULATED WITH A PLASTIC FINISH AND NO NON DESTRUCTIVE INTERNAL INSPECTION PRODUCERS ARE IN THE MANUAL. THE RPTR STATED THE CAUSE OF THE FAILURE WAS WOOD DRY ROT. THE RPTR STATED THIS OLDER PROPELLER WAS INSTALLED TO INCREASE THE ACFT SPEED AND WOULD BE CONSIDERED A RARE INSTALLATION. THE RPTR SAID THE DAMAGE INCURRED WAS LIMITED TO THE TOP ENG MOUNTS; ENG CRANKSHAFT AND LOWER COWLING. THE RPTR STATED NO EMER WAS DECLARED.