The importance of the Royal Air Force surveillance fleet

If modern warfare is a battle of information, then the RAF’s ISTAR fleet is on the front line.

These aircraft, packed with sensors, form a vital but often overlooked part of the UK’s capabilities. From tracking Russian submarines in the North Atlantic to intercepting enemy signals over Eastern Europe, they provide Britain – and NATO – with the intelligence edge needed to deter threats and, when necessary, act decisively.

ISTAR – short for Intelligence, Surveillance, Target Acquisition and Reconnaissance – isn’t as headline-grabbing as fast jets or aircraft carriers. But make no mistake: it is critical.

So, what does the UK’s fleet actually do – and why does it matter?

The RAF has a long tradition of airborne intelligence-gathering, going back to Cold War missions by Canberras and the legendary Nimrod. More recently, the Sentry AEW1 and Sentinel R1 aircraft played central roles in operations over Iraq, Afghanistan, and Libya.

But those aircraft have now retired. In their place is a new, modernised fleet of ISTAR platforms based primarily at RAF Waddington and RAF Lossiemouth. These aircraft – smarter, faster, and more connected than ever – are reshaping how Britain understands and responds to threats.

At the heart of the RAF’s airborne signals intelligence capability is the RC-135W Rivet Joint, known in UK service as Airseeker. Three of these specialist aircraft are in service with No. 51 Squadron, flying regular missions to intercept and analyse radar emissions, communications, and other electronic signals. Whether flying over the Baltics or the Eastern Mediterranean, Rivet Joint provides real-time intelligence to commanders across NATO. It can detect enemy radars, listen in on military communications, and share that data instantly with allied forces.

It’s not glamorous work – but it is utterly indispensable. When tensions spike, it’s often a Rivet Joint that’s first in the air, quietly collecting the information that informs every other move.

Set to replace the RAF’s retired fleet of Sentry early warning aircraft, the E-7 Wedgetail represents a generational leap forward in airborne command and control. Built on a Boeing 737 airframe, its powerful radar can scan hundreds of miles in every direction, tracking enemy aircraft and coordinating friendly ones.

Only three aircraft are on order – down from an original five – but even a small Wedgetail fleet will provide the RAF with a modern, NATO-integrated battle management platform.

Based at Lossiemouth, alongside the Poseidon maritime patrol fleet, Wedgetail will help knit together Britain’s air and naval defences and contribute to NATO’s shared early warning system.

As tensions with Russia have grown, so too has the importance of maritime patrol. Enter the P-8A Poseidon, the RAF’s long-range submarine hunter.

Based on the Boeing 737 and packed with sophisticated sonar buoys, radar, and torpedoes, Poseidon provides round-the-clock surveillance over the North Atlantic – a key transit route for Russian submarines seeking access to the open ocean. It also plays a crucial role in protecting the UK’s nuclear deterrent.

The Royal Navy’s Trident-armed submarines are among Britain’s most important assets – and Poseidon helps ensure they remain undetected and unchallenged.

At the other end of the scale is the Shadow R1, a smaller aircraft designed for tactical surveillance and intelligence-gathering. Flying low over hostile terrain, Shadow can spot hidden threats, support special forces, and feed live imagery back to commanders on the ground.

Originally deployed in Afghanistan, Shadow has since proven its worth in theatres across the Middle East and Africa. With its fleet expanding and new upgrades underway, this workhorse remains a vital link between airpower and operations on the ground.

Britain’s future in unmanned surveillance rests with the Protector RG Mk1, the successor to the well-known Reaper drone. Capable of flying for over 40 hours, Protector will be able to carry out surveillance and precision strikes while complying with UK and European airspace regulations – something its predecessor couldn’t do.

Due to enter service this year, Protector will allow the RAF to maintain a persistent watch over areas of interest across the globe, relaying high-quality intelligence in real time while keeping aircrew out of harm’s way.

Why it all matters

ISTAR doesn’t make headlines. It doesn’t dogfight or drop bombs. But it enables everything that does. By providing early warning, accurate intelligence, and persistent surveillance, the RAF’s ISTAR fleet gives the UK and its allies the ability to deter threats, respond rapidly to crises, and – when necessary – act with precision.

In a NATO context, these capabilities multiply the effectiveness of allied forces. The UK’s platforms are designed to plug into alliance networks, allowing seamless intelligence-sharing and coordination with partners from the US to Norway. This is burden-sharing in action – and a key part of Britain’s contribution to collective defence.

As debates continue to swirl around ship numbers and fighter jet fleets, it’s worth remembering that none of those platforms operate in a vacuum. They rely on the invisible work done by ISTAR assets – monitoring the air, sea and electromagnetic spectrum, 24 hours a day.