TYNDALL AIR FORCE BASE, Fla. — An Air Force F-22 Raptor fighter jet crashed near a Florida Panhandle highway Thursday, but the pilot was able to eject safely and there were no injuries on the ground, the military said. The single-seat stealth fighter, part of a program that has been plagued with problems, went down Thursday afternoon near Tyndall Air Force Base, just south of Panama City on The Gulf of Mexico. The pilot received medical treatment and a section of Highway 98 that runs through the base was closed as rescuers responded. The crash was on Tyndall land and no one on the ground was hurt, said Air Force Sgt. Rachelle Elsea, a spokeswoman for the base where F-22 pilots train. The Air Force said the plane went down in a wooded area near the highway. The cause of the crash isn't clear, but the Air Force has been trying to address problems with the $190 million aircraft for several years. In 2008, pilots began reporting a sharp increase in hypoxia-like problems, forcing the Air Force to finally acknowledge concerns about the F-22's oxygen supply system. Two years later, the oxygen system contributed to a fatal crash. Though pilot error ultimately was deemed to be the cause, the fleet was grounded for four months in 2011. New restrictions were imposed in May, after two F-22 pilots went on the CBS program "60 Minutes" to express their continued misgivings. The Air Force has said the F-22 is safe to fly — a dozen of the jets began a six-month deployment to Japan in July — but flight restrictions that remain in place will keep it out of the high-altitude situations where pilots' breathing is under the most stress. Internal documents and emails obtained by The Associated Press earlier this year show Air Force experts actually proposed a range of solutions by 2005, including adjustments to the flow of oxygen into pilot's masks. But that key recommendation was rejected by military officials reluctant to add costs to a program that was already well over budget.