United Kingdom Thales Group
Watchkeeper WK450
British Army tactical ISTAR UAV co-developed with Elbit Systems from the Hermes 450, carrying a dual EO/IR and SAR/GMTI radar payload for all-weather surveillance.
In service since 2018 · 1 operator countries
Compiled from public sources ·primary reference ↗ ·last verified 2026-07-04
150
km range
4,877
m ceiling
Pricing: No standalone unit price is published. UK programme costs had reached GBP 1.08 billion by March 2018 against an order of 54 airframes, and the estimated cost of reaching full operational capability was put at about GBP 1.2 billion.
Procurement snapshot
Availability & export
UK export-licensed
Subject to UK SPIRE licensing (ECJU); generally available to allied states.
Channel: Government-to-government or direct
Fielded & proven
Limited · 1 operator
In service since 2018. Status: active · ~54 built.
Lifecycle cost (est.)
No public unit price to model from. Why so few systems publish one →
Interoperability
No standardised NATO calibre / datalink detected in public specs.
Derived guidance from public data, export regime by country of origin, lifecycle from the GAO ~30% acquisition rule. Verify eligibility, pricing and offsets with the manufacturer and your acquisition authority.
Full specifications
Performance
Speed, range, altitude and engagement capability.
| Cruise speed Sustained economical speed. Determines transit time to station. | 143 km/h |
|---|---|
| Range Maximum distance: ferry range for aircraft, operational range for vehicles, maximum engagement distance for missiles. Higher means more standoff or persistence. | 150 km |
| Service ceiling Maximum operating altitude. Higher gives energy advantage and sensor horizon. | 4,877 m |
| Endurance Time on station. Critical for UAVs and patrol platforms, higher means longer persistent coverage. On a ground robot, published continuous run time on a full charge or fuel tank. | 14 h |
Physical
Dimensions, weight and crew.
| Length Overall length including gun/probe where applicable. | 6.5 m |
|---|---|
| Wingspan Wingtip-to-wingtip span. | 10.9 m |
| Combat weight Fully loaded weight. Lighter eases transport and bridging limits; heavier often means more armor. | 485 kg |
| Crew Personnel required to operate. Fewer reduces exposure; autoloaders trade a loader for mechanical complexity. | 0 |
Propulsion
Engine, power and fuel.
| Engine Powerplant model and type. | UAV Engines Ltd rotary Wankel engine |
|---|---|
| Engines Number of engines. Twin-engine gives redundancy at higher cost. | 1 |
| Propulsion type Turbofan, turboshaft, diesel, gas turbine, solid-fuel rocket, ramjet… | Rotary (Wankel) piston |
Sensors & avionics
Radar, sensor suite and datalinks.
| Radar Primary radar. AESA (active electronically scanned array) is the current state of the art. | Thales I-Master dual-mode SAR/GMTI radar |
|---|---|
| Sensors IRST, EO/IR turrets, laser designators, sniper pods, thermal sights. | Electro-optical/infrared payload, Dual-mode synthetic aperture radar with ground moving target indication |
Program
Cost, production scale and operators.
| Units built Total production run. Higher means proven manufacturing, mature logistics and spares availability. | 54 |
|---|---|
| Operator countries Number of countries operating the system. More operators means broader support ecosystem. | 1 |
Specifications compiled from public Thales Group and reference sources ↗. Published defense figures are approximations, treat comparisons as directional. Last verified 2026-07-04.
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What is the range of the Thales Group Watchkeeper WK450? +
The Thales Group Watchkeeper WK450 has a maximum range of 150 km.
How much does the Thales Group Watchkeeper WK450 weigh? +
The Thales Group Watchkeeper WK450 has a combat weight of 485 kg.
How many crew does the Thales Group Watchkeeper WK450 require? +
The Thales Group Watchkeeper WK450 requires a crew of 0.
What engine does the Thales Group Watchkeeper WK450 use? +
The Thales Group Watchkeeper WK450 is powered by the UAV Engines Ltd rotary Wankel engine.
How many countries operate the Thales Group Watchkeeper WK450? +
The Thales Group Watchkeeper WK450 is operated by 1 countries.
How much does the Thales Group Watchkeeper WK450 cost? +
Thales Group Watchkeeper WK450: No standalone unit price is published. UK programme costs had reached GBP 1.08 billion by March 2018 against an order of 54 airframes, and the estimated cost of reaching full operational capability was put at about GBP 1.2 billion.. Defense program costs are rarely fully public and vary by contract and configuration.
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