In the late 1960s, the Soviets introduced their MiG-25 Foxbat and claimed it was the best fighter for years to come. The United States was understandably spooked learning that their biggest rival had developed an allegedly perfect fighter bomber capable of reaching Mach 3.2 and comfortably sitting at extreme altitude. So the States got to work and created the F-X program which eventually lead to the creation of the F-15 Eagle. However, the Pentagon still holds the blueprints to the unknown XF-15a Beagle closely since it's mere existence was an embarassment. The Beagle was the first design in the F-X program. It can operate on carrriers, is capable of super sonic flight if you push it hard enough and carries a handful of missiles. It also carries two miniguns. Some people would consider the Beagle a formidable fighter, but the Beagle was agreeably worse than the fighters before it, like the F-4 and F-14. Therefore the Pentagon determined that producing a fighter worse then the fighters before it woudn't be very smart. Group 1 = canopy, group 2 = arresting wire