The F-35 Joint Strike Fighter has exceeded Mach 1 for the first time–a timely achievement after a recent Rand study suggested that the design lacked maneuverability for air-to-air combat. Lockheed Martin said that the Lightning II accelerated to Mach 1.05 with a full internal load of inert weapons–5,400 pounds–on November 13. The design top speed is Mach 1.6. The Rand study on Air Combat discussed the potential performance of U.S. airpower in a conflict with China over Taiwan. In passing, the study noted that the thrust loading of the F-35 “is significantly inferior to that of the F-15, F-16 and F-22, (resulting in) slower acceleration, slower climb and more energy bleed in tight turns.” The Rand authors also claimed that if the F-35A were ever obliged to engage modern Russian/Chinese fighters within visual range, it “can’t turn, can’t climb (and) can’t run.” Last September, F-35 program officials defended the aircraft against previous negative reports from a war-gaming exercise. “The F-35 enjoys a significant combat loss exchange ratio advantage over the current and future air-to-air threats, to include Sukhois,” said U.S. Air Force Maj. Gen. Charles R. Davis, the F-35 program executive officer.