Narrative:

While in cruise at 11000' en route from mem to gtr I noticed a small vibration in the left propeller. A vibration is not unusual so I adjusted the propeller RPM. I told my first officer that I was going to feather the propeller and then take it out of feather. While I had the propeller in feather I had my first officer look out the window in cabin 1A to see if everything looked normal. He came back up to the cockpit when I took the propeller out of feather. At this time the propeller went into what appeared to be an overspd condition. Within a few seconds the right propeller went into the same condition. At this point, the plane became hard to control. I shut the left engine down but with the right engine propeller overspding the plane was still hard to control. I shut the right engine down at this time and put the plane in a stabilized glide. We attempted a restart on the left engine. The start was normal, but when I took the propeller out of feather the propeller went to an overspd condition again. I tried to go to torque motor lockout to correct the situation. I had no choice but to shut down the left engine again. We tried another restart on the left engine, at this point I went to torque motor lockout before the start and the start and unfeather were normal. We climbed to a higher altitude on left engine and decided to go back to mem. We landed safely at mem on runway 36R and taxied to the company hangar. There were no passengers on board. The crew consisted of myself, my first officer and the F/a. Nobody was hurt and the plane was not damaged. I can say that we as a crew were not trained for this kind of situation.

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Original NASA ASRS Text

Title: OVERSPEED PROPS ON BOTH ENGINES REQUIRED ENGINE SHUT DOWN. FLC MANAGED TO RESTART ONE ENGINE. RETURN TO MEM.

Narrative: WHILE IN CRUISE AT 11000' ENRTE FROM MEM TO GTR I NOTICED A SMALL VIBRATION IN THE L PROP. A VIBRATION IS NOT UNUSUAL SO I ADJUSTED THE PROP RPM. I TOLD MY F/O THAT I WAS GOING TO FEATHER THE PROP AND THEN TAKE IT OUT OF FEATHER. WHILE I HAD THE PROP IN FEATHER I HAD MY F/O LOOK OUT THE WINDOW IN CABIN 1A TO SEE IF EVERYTHING LOOKED NORMAL. HE CAME BACK UP TO THE COCKPIT WHEN I TOOK THE PROP OUT OF FEATHER. AT THIS TIME THE PROP WENT INTO WHAT APPEARED TO BE AN OVERSPD CONDITION. WITHIN A FEW SECS THE R PROP WENT INTO THE SAME CONDITION. AT THIS POINT, THE PLANE BECAME HARD TO CTL. I SHUT THE L ENG DOWN BUT WITH THE R ENG PROP OVERSPDING THE PLANE WAS STILL HARD TO CTL. I SHUT THE R ENG DOWN AT THIS TIME AND PUT THE PLANE IN A STABILIZED GLIDE. WE ATTEMPTED A RESTART ON THE L ENG. THE START WAS NORMAL, BUT WHEN I TOOK THE PROP OUT OF FEATHER THE PROP WENT TO AN OVERSPD CONDITION AGAIN. I TRIED TO GO TO TORQUE MOTOR LOCKOUT TO CORRECT THE SITUATION. I HAD NO CHOICE BUT TO SHUT DOWN THE L ENG AGAIN. WE TRIED ANOTHER RESTART ON THE L ENG, AT THIS POINT I WENT TO TORQUE MOTOR LOCKOUT BEFORE THE START AND THE START AND UNFEATHER WERE NORMAL. WE CLBED TO A HIGHER ALT ON L ENG AND DECIDED TO GO BACK TO MEM. WE LANDED SAFELY AT MEM ON RWY 36R AND TAXIED TO THE COMPANY HANGAR. THERE WERE NO PAXS ON BOARD. THE CREW CONSISTED OF MYSELF, MY F/O AND THE F/A. NOBODY WAS HURT AND THE PLANE WAS NOT DAMAGED. I CAN SAY THAT WE AS A CREW WERE NOT TRAINED FOR THIS KIND OF SITUATION.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.