A 2018 study by the U.S. Government Accountability Office (GAO) found that the average age of the U.S. military's F-16 fighter jets was 27 years in 2016, and the "Air Force plans to keep the F-16 fleet flying until 2046 through a service life extension." Per the Air Force, "the F-16 has been a major component of the combat forces committed to the war on terrorism flying thousands of sorties in support of" anti-terror operations. The GAO also found that 10 of the 12 military aircraft they studied "are experiencing sustainment challenges related to aging; all 12 are experiencing challenges related to maintenance; and all 12 are also experiencing challenges related to supply support."