The U.S. State Department has approved three potential Foreign Military Sales for fighter aircraft, cargo helicopters and UAV support worth up to $4.7 billion. The largest is a request by Slovakia to purchase up to 14 new Lockheed Martin F-16 Block 70/72 Viper aircraft, a deal worth as much as $2.9 billion for the most advanced version of the fourth-generation fighter. To outfit those aircraft, the Slovak Republic has asked for F110 General Electric or F100 Pratt & Whi tney engines, ...