Tweet   The Navy plans to carry out a large-scale drill from Friday on all three sides of the peninsula until Sunday this week, which marks first anniversary of the sinking of the corvette Cheonan by North Korea.   A government official on Thursday said Naval fleets are scheduled for a three-day drill from Friday. Each fleet will mobilize patrol planes and frigates for training based on anti-surface, an More..ti-submarine and anti-air warfare scenarios. The Army and Air Force also plan a joint artillery drill using K-9 self-propelled artillery, 130 mm multiple launch rocket system, and K-15K fighter jets in Pocheon, Gyeonggi Province on Thursday.