Thales Watchkeeper WK450
|Flight trials at Parc Aberporth in 2013|
|Role||Unmanned aerial vehicle|
|National origin||United Kingdom|
|First flight||14 April 2010|
|Status||In limited service|
|Primary user||British Army|
|Developed from||Elbit Hermes 450|
The Thales Watchkeeper WK450 is a Remotely Piloted Air System (RPAS) for all weather, Intelligence, surveillance, target acquisition, and reconnaissance (ISTAR) use by the British Army, provided under an £800 million contract awarded in July 2005 to U-TacS partnership between Elbit and Thales UK. The air-vehicle is based on Elbit's Hermes 450.
The Watchkeeper WK450 is based on the Elbit Hermes 450 UAV. The engine is a rotary Wankel engine. It has a mass of 450 kg and a payload capacity of 150 kg, with a typical endurance of 17 hours. It was originally intended to enter service in June 2010.
The Watchkeeper is built in the UK by a joint venture company, UAV Tactical Systems (U-TacS), set up by the Israeli company Elbit Systems (51% ownership) and the Thales group. UAV Engines Ltd, who build the rotary engine in the UK, is a wholly owned subsidiary of Elbit Systems. The majority Israeli ownership has caused some unexpected problems obtaining U.S. export authorisation for anti-icing components. A prime difference between the Hermes 450 and Watchkeeper is that the 450 is fitted only with an electro-optical/infrared sensor, while the WK450 has a dual-mode synthetic aperture radar and ground moving target indication that allow it to see through weather conditions such as dust storms that the Hermes aircraft can not. The drone can maintain its radio control signal 150 km (93 mi) from its ground station.
On 15 July 2007, the UK MoD revealed that 54 Watchkeepers will be delivered to the British Army. The average cost to the taxpayer is therefore £800m divided by 54 aircraft, approximately £15m per platform. However, this figure includes construction of new basing facilities at Boscombe Down airfield, ground training facilities and simulators at the School of Artillery, Viking armoured vehicles and other equipment for tactical parties, ground control stations, development and testing of extensive aircraft modifications including automatic take-off and landing and the integration and provision of new sensors including radars.
In October 2010, the contract was extended by a further 18 months, and the delivery date slipped. Deployment by the Royal Artillery was said to be imminent in 2013, though certification by the Military Aviation Authority was still awaited. As of 2013, the programme was running about three years late; in September, release to service approval was expected to be granted before the end of the year. British Army officials said the Watchkeeper could enter service in spring 2014. As of January 2014, 26 air vehicles have been produced with another 28 on order, and 14 ground control stations have been produced with one more on order. Watchkeeper aircraft had performed over 600 flights totaling 950 flight hours. The Watchkeeper system will be in service with the British Army until 2040.
The Royal Artillery has a future aspiration to weaponise Watchkeeper.
In March 2014, the Watchkeeper was cleared for military flight training with the Royal Artillery. Operating out of Boscombe Down in Wiltshire, 1st Artillery Brigade is training with the Watchkeeper in restricted airspace over Salisbury Plain between 8,000 and 16,000 feet.
Thales announced on 1 September 2015 that it was teaming with Polish company WB Electronics to offer the Watchkeeper for the Polish armed forces. The requirement calls for an armed UAS capability, so Thales is offering its FreeFall Lightweight Multi-role Missile (FFLMM) for strike missions.
As of December 2015, the British Army had 36 Watchkeeper aircraft but only six pilots, two of them civilians. Needing to train pilots more rapidly but with the aircraft encountering problems flying in the rain, snow, wind, and icy conditions of winter in western Britain, by January 2016 aircraft and pilots will be sent to the tropical oversees territory of Ascension Island, located off Africa's west coast just below the equator, lasting until August. Although the Watchkeeper briefly deployed to Afghanistan for two months in late 2014, pilot shortages will prevent another operational deployment until late 2016. A Parliamentary reply further revealed that 37 Watchkeepers were delivered by 15 December 2015 and that FOC would be achieved by second quarter 2017.
On 29 September 2014, the MoD revealed that an undisclosed number of Watchkeepers had become fully operational and sent to Afghanistan. The aircraft were stationed at Camp Bastion to provide force protection for British troops as they drew down from Afghanistan towards the end of the year. There had been no prior indication that the Watchkeeper would be sent to Afghanistan before the NATO-led International Security Assistance Force completed its mission. The aircraft worked alongside Hermes 450s that it is derived from, although the Watchkeeper carries a twin payload of an electro-optical/infrared sensor and a synthetic aperture radar.
One system of four Watchkeepers was sent to Afghanistan in August 2014, performed its first in-theatre flight on 2 September, and conducted the first operational flight on 16 September. One mission had a Watchkeeper providing wide-area surveillance for U.S. Marines using its Thales I-Master radar, which then cued a Hermes 450 to continue tracking, which then passed the information on to a Royal Air Force MQ-9 Reaper to conduct an airstrike against a target. Some 140 flights were conducted for 8 hours a day until operations ceased in mid-October. One reason the WK450 was deployed so late in the conflict was to use its dual-mode synthetic aperture radar and ground moving target indication, which the Hermes 450 lacks, to identify Taliban fighters attempting to hide under the cover of dust storms; when the ground-based radar coverage at Bastion was switched off, the British Army stopped using the interim leased Hermes 450. Once operations in-theatre ceased, the Watchkeepers were brought back to the UK. Full operational capability is to be achieved in 2017 with enhancements including de-icing features, rough strip capabilities, and others. A message from the commander of 47th Regiment Royal Artillery stated that his regiment will be the sole operator of the Watchkeeper and that 43 Battery is looking now at deploying to the Ascension Island Base in the southern Atlantic for a prolonged period of WATCHKEEPER flying. 
- Lewis Page (2 March 2011). "Blighty's expensive Watchkeeper spy-drone in further delays". The Register. Retrieved 5 March 2011.
- Major Subsidiaries. Elbit Systems. Retrieved 2009-01-03.
- Darren Lake (August 30, 2006). "US DoD denies export of key system for UK Watchkeeper Programme". Shephard UVOnline. Archived from the original on 2007-09-28. Retrieved 2007-09-28.
- British Army praises performance of Watchkeeper during debut deployment - Flightglobal.com, 17 November 2014
- Army moves Watchkeeper drone training to tropics for winter after flying problems in UK weather - Thebureauinvestigates.com, 11 December 2015
- Lewis Page (15 June 2007). "UK MoD reveals Watchkeeper spy-drone numbers". The Register. Retrieved 2009-01-03.
- WATCHKEEPER makes first UK flight. Thales. Retrieved 2010-04-15.
- "The UK’s Watchkeeper ISTAR UAV". Retrieved 2010-10-30.
- Michael A. Taverna (28 February 2011). "Watchkeeper Gets New Delivery Date". Aviation Week. Retrieved 5 March 2011.
- Service Inquiry investigating the accident involving Unmanned Air System (UAS) Hermes 450, ZK515 on 02 Oct 11 (Report). Ministry of Defence. 30 March 2012. p. Part 1.6 - 2. Retrieved 3 August 2013.
- Chris Pocock (21 June 2013). "French Must Choose: Patroller or Watchkeeper?". AINonline. Retrieved 3 August 2013.
- Craig Hoyle (16 April 2013). "Where are all the Watchkeepers?". Flightglobal. Retrieved 3 August 2013.
- Hoyle, Craig (September 10, 2013). "Watchkeeper nears delayed service introduction". FlightGlobal. Retrieved 2013-09-30.
- British Army Watchkeeper UAV May Debut In Spring - Aviationweek.com, 15 January 2014
- British Army confident on Watchkeeper service entry - Flightglobal.com, 16 January 2014
- France negotiates acquisition of Watchkeeper drones against purchase of VBCI armoured by UK - Armyrecognition.com, 20 February 2014
- "Newest eye in the sky Watchkeeper cleared to fly". Retrieved 2014-03-05.
- WB Electronics and Thales unveil their Unmanned Aircraft System for Polish Gryf programme - Thalesgroup.com, 1 September 2015
- Watchkeeper fully operational in Afghanistan, UK reveals - Flightglobal.com, 29 September 2014
|Wikimedia Commons has media related to Thales Watchkeeper WK450.|
- Official website
- Announcement of contract in the House of Commons, Hansard column 86WS, 20 Jul 2005
- UK Gives $1.23B Green Light to Watchkeeper UAV, Defense Industry Daily, 25 July 2005
- Watchkeeper bidders, Spyflight