What was found
SECOND BEFORE ROTATION, A LOUD BANG AND LOSS OF POWER ON NR 1 ENGINE OCCURRED. PROPELLER WENT INTO FEATHER. INSPECTION OF NR 1 ENGINE, NO DEFECTS FOUND, BUT ENG WOULD NOT TURN MORE THAN 600 RPM. PROPELLER WOULD NOT COME OUT OF FEATHER. REPLACED PROPELLER. NR 1 ENG CHECKED OUT NORMAL. TEAR DOWN OF PROP REVEALED THE PTICH CHANGE ROD WAS SEVERED JUST AFT OF PISTON, PN B-3237, RETAINING FLANGE CROSSING PROP TO ABRUPTLY GO INTO FEATHER. PITCH CHANGE ROD BEING FORWARDED TO HARTZELL FOR FURTHER INVESTIGATION. PROP TSO, 274.00 HRS.