Aviation Week 2 July 1990
Tests Begin Soon for New Weapon To Blend Into Stealth Aircraft Skin
Flight tests are set to begin this month on the composite-skinned Have Slick missile, a U. S. Air Force stand-off weapon expressly designed to blend into the shape of stealth aircraft. The missile may prove to be the forerunner of a new class of air-to-ground weapons conceived to supplement the relatively small, internal weapon loads of such aircraft as the F-117, A-12, B-2 and advanced tactical fighter (as the ATF evolves an attack mission).
Have Slick is designed to avoid the detrimental effects of externally hung conventional weapons on the flying characteristics and radar signature of stealth aircraft. After launch, these fast, stand-off weapons would cruise a battlefield searching for targets and dropping submunitions with great precision. However, the Pentagon likely will give little overt attention or funding to such weapon programs until after the next generation of stealth aircraft (ATF, A-12) are in service, an official said. The Defense Dept. does not want its congressional critics to know the missile necessary to make stealth aircraft truly formidable weapon platforms has yet to be built and paid for.
By the end of July, the Air Force will start launching Have Slick missiles—a 14 x 2-ft., 2,000-lb.-class weapon—from an F-111E, service officials said. The air drops will closely follow a series of captive carry tests.
Primary goal of the $13.2-million project is to create a low—drag weapon. Existing bombs and missiles and their pylons slow an aircraft, shorten range and hinder the ability to evade enemy fighters and antiaircraft weapons. While a contemporary 2,000-lb. weapon mounted on an F-15 will increase the fighter’s drag by about 25%, the Have Slick should increase drag only 2.5% by eliminating blunt, extruding shapes, an Air Force official said.
Details of Have Slick’s “complex” shape are classified, but it is known to have four control surfaces on the tail and a flat underside that functions as a lifting surface or wing. The flat belly also serves to mount the missile flush with the aircraft’s skin for conformal carriage, Aaron Brinson, chief of the flight vehicles branch of Munitions Systems Div. at Eglin AFB, Fla., said. For Have Slick tests, the F-111's bomb bay doors were removed and the aircraft was fitted with a conformal ejection rack. Two high powered pistons will kick the missile away from the aircraft.
Using the fuselage as an airfoil requires an aircraft-type autopilot that can bank Have Slick through turns rather than skidding it like most missiles, Brinson said. The resulting ability to conduct high-g maneuvers will give the missile great agility. A Have Slick-type missile should be able to fly 20 mi., perhaps many more, to its target areas at supersonic speed and then slow for better accuracy, an Air
Force official said. After dropping its submunitions in one or more target areas, the missile would crash into the ground and be destroyed.
Except for some problems with the electrical interface between missile and aircraft, the captive carry tests went as expected, Brinson said. The subsequent series of 6-10 free flight tests should be completed in September. The F-111E will drop Have Slick missiles at speeds ranging from Mach 0.6 to 1.05 and altitudes from 10,000 to 4,500ft., he said. Originally, program officials had planned to test the missile at a top speed of Mach 1.6 but usable space on the Eglin ranges forced a reduction in the test envelope, an official said.
At the end of flight testing, administrators of the program will turn to analysis of the data and validation of their simulations, Brinson said. If the advanced materials and shaping, technology and conformal carriage of the missile prove themselves, they may be incorporated into the next generation of airborne stand-off weapons, scheduled to begin development in Fiscal 1993-94.
In addition to agility and speed, Have Slick missiles are made of light, extremely tough glass fiber-epoxy and graphite-epoxy composites in a shape that is less visible to radar than traditional weapons, Brinson said. With strength concentrated in the skin, designers can eliminate internal bulkheads and other supports that drive up missile weight. Only the missile’s spine, or strongback, is made of metal to ensure it withstands the shock of ejection pistons, but in a production model it too may be made of composites, officials said.
Have Slick was described as a “shotgun shell” that can be tightly packed with a large range of submunitions. The composite-skinned missile will carry more than half its weight in ordnance, about 1,200 lb. or 50% more than existing cluster bombs and other aerial munition dispensers, an Air Force official said.
The missile’s design would allow carriage of two Have Slicks on an F-16-size aircraft and four on a larger F-15E—size design, an Air Force official said. While Have Slick missiles could be fitted to these older aircraft, the size and weight of the launchers would dictate its primary use on newer aircraft such as the F—117.
