Narrative:

Right-hand engine experienced roughness while in cruise flight. Eventually; r-hand engine became so rough and began shaking so badly that the engine had to be shut down. I elected to fly on to ZZZ (about 15 mins away) because the WX was VFR at that airport. Although I was closer to ZZZ1; the WX reported for that airport was MVFR. I declared an emergency with ATC and went on to land at ZZZ without incident. Perhaps I should have explored landing at other closer airports; however; I had about 5000 ft of altitude to lose and felt that a safe landing could be made at ZZZ. Additionally; perhaps I should have detected the engine problem earlier and/or made changes to the flight accordingly.

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Original NASA ASRS Text

Title: A BE55'S R ENG WAS SHUT DOWN AFTER RUNNING ROUGH. THE NEARBY MARGINAL ARPT WAS NOT USED BECAUSE OF THE ACFT ALT AND A SLIGHTLY FURTHER ARPT WAS VFR.

Narrative: R-HAND ENG EXPERIENCED ROUGHNESS WHILE IN CRUISE FLT. EVENTUALLY; R-HAND ENG BECAME SO ROUGH AND BEGAN SHAKING SO BADLY THAT THE ENG HAD TO BE SHUT DOWN. I ELECTED TO FLY ON TO ZZZ (ABOUT 15 MINS AWAY) BECAUSE THE WX WAS VFR AT THAT ARPT. ALTHOUGH I WAS CLOSER TO ZZZ1; THE WX RPTED FOR THAT ARPT WAS MVFR. I DECLARED AN EMER WITH ATC AND WENT ON TO LAND AT ZZZ WITHOUT INCIDENT. PERHAPS I SHOULD HAVE EXPLORED LNDG AT OTHER CLOSER ARPTS; HOWEVER; I HAD ABOUT 5000 FT OF ALT TO LOSE AND FELT THAT A SAFE LNDG COULD BE MADE AT ZZZ. ADDITIONALLY; PERHAPS I SHOULD HAVE DETECTED THE ENG PROB EARLIER AND/OR MADE CHANGES TO THE FLT ACCORDINGLY.

Data retrieved from NASA's ASRS site as of May 2009 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.