Lessons learned during the 1999 Kosovo conflict identified the need for the RAF to be able to strike static, mobile and armoured targets accurately in all weathers and 24 hours a day.
The Enhanced Paveway (EPW) family of weapons was procured to meet this requirement and the EPWII entered RAF service in 2001 and the larger EPWIII entered service in late 2002. Both weapons are carried by Tornado GR4.
Both EPWII and EPWIII are based on the laser-guided bombs Paveway II and Paveway III respectively, already in RAF service, and use the same warheads and fin sections.
However, the EPW weapons have a modified guidance section and wiring to accommodate a Global Positioning System Aided Inertial Navigation System (GAINS).
Once released from the launch aircraft, EPW is fully autonomous in cases where there is cloud cover over the target which may obstruct the laser and prevent weapon guidance. In these instances, it is steered to the target using Global Positioning System (GPS) information as well as guidance from its on-board inertial navigation unit.
In good weather, or where rules of engagement are more demanding, aircrews can guide the weapon to the assigned target using the laser guidance contained within both weapons. Laser designation may be provided from the air using a Laser Designator, or from forces on the ground using a laser target designator.
The EPWII includes a 450kg general- purpose warhead; the EPWIII includes the 900kg class penetrator warhead. Both of the EPW variants have demonstrated the same degree of accuracy in their laser mode (without the use of GAINS) as their predecessors, and highly accurate results have been achieved on trials using the GPS autonomous mode. Both LGBs have been well-received by the RAF. These weapons were used during operations in Iraq in 2003.