On 30 November 2014, an ATR 72-500 suddenly experienced severe propeller vibrations whilst descending through approximately 7,000 feet with the power levers at flight idle. The vibrations subsided after the crew feathered the right engine propeller and then shut the right engine down. The flight was completed without further event. Severe damage to the right propeller mechanism was found with significant consequential damage to the engine. Several other similar events were found to have occurred to other ATR72 aircraft and, since the Investigation could not determine the cause, the EASA was recommended to impose temporary operating limitations pending OEM resolution.