The GBU-27 is a 2,200 pound laser-guided bomb designed specifically for use by the F-117 Stealth Fighter. It is a highly accurate, hard-structure munition compatible with the F-117's advanced target acquisition/designator system. The GBU-27 uses a BLU-109 improved performance 2,000 pound bomb developed in 1985 under the project name HAVE VOID. The BLU-109 was designed for use against hardened structures and features a high-strength forged steel case and a new delayed-action tail fuze. It carries 550 pounds of high explosives and can penetrate more than six feet of reinforced concrete before exploding.
The GRU-27 uses a modified Paveway II guidance control unit which provides "terminal trajectory shaping" for optimum impact angle against various target structures. For example, it will hit an aircraft shelter with a vertical impact, but make a horizontal approach to a bridge support. A Paveway II tail assembly with folding wings completes the bomb.
The F-117 can carry two GBU-27s in two weapons bays and is reportedly capable of hitting a one square meter target from an altitude of 25,000 feet. The GBU-27 was used extensively during Desert Storm, with a claimed hit probability of over 95 percent. The weapon on display was received from the F-117 System Program Office at Wright-Patterson AFB, Ohio, in September 1991.
