Paveway

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A Paveway III seeker head, at the RAF Museum in Hendon, London.

Paveway III at ILA airshow 2006

Paveway™ is a trademark of Raytheon Company which identifies its variants of Laser Guided Bombs (LGB). Lockheed Martin became a second source supplier of LGBs in 2001. PAVE is an acronym standing for Precision Avionics Vectoring Equipment, and was also used for the names of various laser designator pods used with these weapons, including Pave Penny, Pave Spike, Pave Tack and Pave Knife. The orginal use of the Paveway™ name applied to both the guided weapon, and a designator, but this was soon dropped and applied to only the weapon.

It has also been used for military aircraft variants equipped with specialized avionics, such as the AC-130U Pave Spectre and MH-60 Pave Hawk.

The Paveway™ series of laser-guided bombs was developed by Texas Instruments starting in 1964. The program was conducted on a shoestring budget, but the resultant emphasis on simplicity and economical engineering proved to be a benefit, and a major advantage over other more complex guided weapons. The first test weapon, using a Mk 117 bomb as the warhead, took place in April 1965. Prototype weapons were sent to Vietnam for combat testing starting in 1968.

Paveway™ kits attach to a variety of warheads, and consist of a semi-active laser (SAL) seeker, a computer control group (CCG) containing guidance and control electronics, thermal battery, and pneumatic control augmentation system (CAS). There are front control canards and rear wings for stability. The weapon guides on reflected laser energy: the seeker detects the reflected light ("sparkle") of the designating laser, and actuates the canards to guide the bomb toward the designated point.

The original Paveway™ series, retroactively named Paveway™ I, gave way in the early 1970s to the improved Paveway™ II, which had a simplified, more reliable seeker and pop-out rear wings to improve the weapon's glide performance. Both Paveway™ I and Paveway™ II use a simple 'bang-bang' control system, where the CAS commands large canard deflections to make course corrections, resulting in a noticeable wobble. This had relatively little effect on accuracy, but expends energy quickly, limiting effective range. As a consequence, most users release Paveway™ I and II weapons in a ballistic trajectory, activating the laser designator only late in the weapon's flight to refine the impact point.

Image:Paveway™ III laser guided bomb.jpg

A Paveway™ III laser guided bomb.

In 1976 the USAF issued a requirement for a new generation, dubbed Paveway™ III, that finally entered service in 1986. The Paveway™ III system used a much more sophisticated seeker with a wider field of view and proportional guidance, minimizing the energy loss of course corrections. Paveway™ III has a considerably longer glide range and greater accuracy than Paveway™ II, but it is substantially more expensive, limiting its use to high-value targets. Although Paveway™ III kits were developed for the smaller Mk 82 weapons, aerodynamic instability and limited effectiveness caused the USAF to adopt the kit only for the larger 2,000 lb-class weapons (the Mk 84 and BLU-109. Paveway™ III guidance kits were also used on the GBU-28/B penetration bomb fielded at the close of the 1991 Gulf War. The Paveway™ III was also used during the Indian offensive in the Kargil War in 1999. Raytheon, the sole provider of Paveway™ III variants, is currently delivering both standard and enhanced versions to the US Government and foreign customers.

Existing LGBs in US service can be upgraded to Dual Mode Laser Guided Bombs(DMLGB) by adding GPS receivers which enable all weather employment. Lockheed Martin won the initial contract to provide DMLGBs to the US Navy (USN) in 2005. Raytheon's version, the "Enhanced Paveway™ II, has been contracted both domestically and abroad.

An advanced Paveway IV series is being developed for export, including Britain's RAF, but it appears that the USAF remains committed instead to the small-diameter bomb program.

The Paveway series of bombs includes: