Operational testing and evaluation of the F-35A has begun, with the delivery of four aircraft to Nellis AFB. They were accepted by the U.S. Air Force Warfare Center in a ceremony on March 19. Eight more F-35As will join them by 2019. The Air Force has now received 24 F-35A conventional takeoff and landing aircraft. Another 34 F-35s have been delivered to the U.S. Marine Corps and U.S. Navy.