August 12, 2008:  Pakistan is paying a Turkish firm to upgrade elderly Pakistani F-16s from Block 15 configuration to Block 40 (about halfway to the highest upgrade level for an F-16). Now that the U.S. has lifted its arms embargo on Pakistan, there are many firms competing for all the work needed to update older American weapons still used by Pakistan. The Turks have long had good trade relations with Pakistan, and have also developed, with the help of the U.S. and Israel, a growing aircraft maintenance and upgrade industry. Most of the F-16 work will be done in Pakistan, using Turkish engineers and technicians supervising some local workers, and using largely imported (from Turkey and elsewhere) components. Turkey has long maintained one the largest F-16 fleets outside of the United States.