Two firms, Raytheon Corp and Northrop Grumman Corp, are bidding for the AESA program and Seoul is expected to make its decision this month or next month.The US Air Force, which is also scheduled to upgrade 350 of its F-16s, could save money by having other countries, such as Taiwan or South Korea, pay for the NRE costs.In February, the Executive Yuan informed the air force that it would only allow