October 28, 2015: The British Army WH450 Watchkeeper UAV acquired weapons (Hellfire and smaller missiles) in 2015. Britain finally got Watchkeeper, its own locally made large UAV operational in late 2013 and since 2014 some have been seen in Afghanistan. This has been a long time coming because it was back in 2006 that the British began developing the Watchkeeper UAV and by 2010 got one airborne for the first time. The Watchkeeper 180 and the Watchkeeper 450 are both based on Israeli designs (the Hermes 180 and 450). The two Watchkeepers were supposed to be ready for service in 2010, but various problems delayed that until the end of 2013. The smaller 180 model was dropped and work continued on the Predator sized 450.

The Watchkeeper 450 is a 450 kg (992 pound) aircraft with a payload of 150 kg. It was always capable of carrying Hellfire missiles, as the Israeli Hermes 450 it is based upon is able to carry two Hellfire type missiles. Until 2015 Watchkeeper did not have a weapons capability but that changed as it became clear that armed UAVs were very useful battlefield weapons. The Watchkeeper is also designed to carry two extra fuel tanks under its wings as well as a radar in addition to the usual day/night vidcams. Each of these radar pods or fuel tanks weighs more than the 50 kg (110 pound) Hellfire missile.

The Watchkeeper 450 is 6.5 meters (20 feet) long and has an 11.3 meter (35 foot) wingspan. It can stay in the air for up to 20 hours per sortie and fly as high as 6,500 meters (20,000 feet). The Hermes 450 is the primary UAV for the Israeli armed forces, and twenty or more were in action each day during the 2006 war in Lebanon and even more during the 2008 and 2014 operations in Gaza. Thirty Watchkeeper 450s have already been delivered to the British Army, with a 24 more on order.