Complex sentence: The Bulgarian navy will modernise three of its Wielingen-class frigates by 2014, the frigates will be equipped with landing pads, allowing helicopters to land and take off from the ships' decks.
Split into simpler sentences: The Bulgarian Navy will modernise three of its "Wielingen"-class frigates by 2014. The frigates will be equipped with landing pads, allowing helicopters to land and take off from the ships' decks.