RV4 PLT CLBS INTO MEM CLASS B AIRSPACE WHILE ATTEMPTING TO CTL A PROP OVERSPD.

Narrative

THIS ACFT; RV4-200; WITH LYCOMING I0-360A1B6; WAS BEING TEST FLOWN AFTER ENG REBUILD AND NEW PROP AND PROP GOVERNOR INSTALLATION. THIS ENG IS EXPERIMENTAL IN NATURE AS IT UTILIZES HIGHER COMPRESSION PISTONS; COLD AIR INDUCTION; AND 4 INTO 1 EXHAUST; TO NAME A FEW. ALSO INSTALLED WAS A NEW WHIRLWIND 150 SERIES PROP WITH MATCHING JIHOSTROJ PROP GOVERNOR. ALL GND RUNS WERE SATISFACTORY; AND INITIALLY THE TEST FLT WAS UNEVENTFUL. AFTER THE 3RD OR 4TH RACETRACK PATTERN WAS FLOWN AROUND MY HOME ARPT (M01); I DECIDED TO CONTINUE THE FLT NE OF THE FIELD. HOWEVER; JUST AFTER MAKING THE RADIO CALL ON CTAF THAT I WAS DEPARTING THE PATTERN; THE PROP GOVERNOR APPARENTLY FAILED; AND A SUBSEQUENT PROP OVERSPD IMMEDIATELY FOLLOWED. I HAD BEEN FLYING AT 1500 FT AGL TO HAVE ALT TO MAKE IT BACK TO THE ARPT AND TO STAY BELOW MEM CLASS B AIRSPACE; AND WAS FLYING WITH WIDE OPEN THROTTLE; AND THE PROP LEVER FULL FORWARD (MAX RPM). WITH NO WARNING; THE RPM ROSE RAPIDLY; AND THROTTLE MOVEMENTS HAD LITTLE OR NO EFFECT. THE ONLY OPTION WAS TO LOAD THE AIRPLANE UP (WHILE SLOWING DOWN) BY PULLING INTO A CLBING TURN. AS I CAME THROUGH 1800 FT AGL (INTO MEM CLASS B); I WAS ABLE TO CTL THE OVERSPD AT 3200 RPM AND SLOWLY DSNDED BACK TO THE ARPT UNEVENTFULLY. I NEVER SPOKE WITH ZME ON THE RADIO; OR WHEN ON THE GND. MY THOUGHTS WERE ONLY OF RETURNING THE ACFT BACK TO THE GND SAFELY. AND ONCE ON THE GND; IT WAS DISCOVERED THAT ONE OF THE PROP BLADES HAD LOOSENED ITSELF FROM THE HUB AS A RESULT OF THE OVERSPD.