What was found
WHILE IN CRUISE FLIGHT ABOVE 10,000 FEET, THERE WAS INSUFFICIENT PITCH TO REDUCE RPM TO CRUISE CONDITION. PROPELLER HUB DISASSEMBLED, AND FOUND A BROKEN PROPELLER RETURN SPRING WAS INTERFERING WITH THE HIGH PITCH STOP, SUCH THAT ONLY 27 DEGREES OF PITCH WERE ALLOWED INSTEAD OF 32 DEGREES.