(FROKA), the Third Army (TROKA), and the Second Operational Command, each with its own headquarters, corps, and divisions. The Third Army was responsible for the defense of the capital as well as the western section of the DMZ. The First Army was responsible for the defense of the eastern section of the DMZ whereas the Second Operational Command formed the rearguard. Under a restructuring plan aimed at reducing redundancy, the Second ROK Army was converted into the Second Operations Command in 2007, and the First and Third ROK Armies were merged as the Ground Operations Command in 2019. Equipment The army consists of 365,000 troops, approximately 2,200 tanks, 3,100 armored fighting vehicles, 5,600 artillery pieces, 60 guided missile systems, and 620 helicopters as of 2022. Main battle tank types include: 400 M48 Patton series and its upgrades such as the M48A3K, M48A5, and M48A5K, 33 Soviet T-80U and 2 T-80UK (given by Russia to pay off debt), as well as 1,511 K1A1 and K1 tanks, which bear a 120mm smoothbore gun and are of local manufacture. The future replacement for the K1 and K1A1 MBTs has been named the K2 Black Panther (흑표;黑豹 Heukpyo), which will be fitted with a 1500hp MTU-based engine, 55-caliber 120mm main gun with autoloader. The new tank will also feature radar equipment as well as all-bearing laser detection and defense systems, anti-missile active protection, and heavy reactive armor and sensor package comparable to the American M1A2 Abrams and the German Leopard 2A6. The ROK Army is planning to field approximately 443 Black Panthers. In addition, the Republic of Korea manufactures the K-9 howitzer which has been exported to Turkey as the T-155 howitzer as well as the ZMA series TIFV's which saw action in UN peacekeeping operations (PKO) as part of the Malaysian peacekeeping forces. A variation of the K200, the KAFVs can be retrofitted to bear a 90mm cannon, 40mm grenade turret, M230-1 Chaingun Turret, or MK-30 Chaingun Turret. A replacement for the K200 series IFVs are currently being tested, designated as the K21 KNIFV (Korea Next Generation Infantry Fighting Vehicle), which will have various capabilities for both land and naval warfare. The initial production is set for 2008, with the ROK Army planning to field approximately 600 units. The K21 KNIFV's chassis will be constructed entirely out of fiberglass, reducing the vehicle's load and enabling it to travel at higher speeds without bulky