British surveillance aircraft were operating in the Baltic region this week.

Royal Air Force RC-135 and Sentinel surveillance aircraft were observed operating over the Baltic nations near the Russian border.

The Open Source Intelligence Twitter account Intel Air & Sea followed the event earlier, if you don’t follow them then I’d suggest you go do that now.

What does the RC-135W do?

According to the Royal Air Force website, the RC-135W Rivet Joint is a dedicated electronic surveillance aircraft that can be employed in all theatres on strategic and tactical missions. Its sensors ‘soak up’ electronic emissions from communications, radar and other systems.

“RC-135W Rivet Joint employs multidiscipline Weapons System Officer (WSO) and Weapons System Operator (WSOp) specialists whose mission is to survey elements of the electromagnetic spectrum in order to derive intelligence for commanders.”

The Royal Air Force say that Rivet Joint has been deployed extensively for Operation Shader and on other operational taskings. It had been formally named Airseeker, but is almost universally known in service as the RC-135W Rivet Joint.

The UK operates three of these aircraft.

What does Sentinel do?

The Sentinel is an airborne battlefield and ground surveillance aircraft based on the Bombardier Global Express ultra long range business jet and serves a role similar to JSTARS with the RAF, the jet was adapted by Raytheon to meet the RAF’s requirements.

Sentinel operates in three modes: spotlight SAR, with 5-meter resolution for small-area surveillance of fixed targets; swath SAR, which provides large-area surveillance of fixed targets; and large-area surveillance of moving targets (including helicopters) travelling at a minimum of 10 kmph.

The system’s operating altitude is between 12,802 metres and 15,200 metres. From this height, its radar sensors are able to detect targets at a range of up to 300 kilometres (186.4 miles). Aside from battlefield scenarios, Sentinel can be used to monitor natural disasters, pollution, and smuggling activities.

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Captain P Wash

This answers the question raised a few days back about Russia sending Bears to snoop around the UK. Yes we do the same.

Mark F

They started it.👍

Captain P Wash

Ha Ha.

Daniele Mandelli

This is ongoing since the start of the Cold War.

Even if Russian flights have increased in the 2000’s with Putin, NATO and the US especially never stopped their own activities.

The USAF were flying aircraft over Siberia in the 50’s and Urals in the 60’s.
The RAF flew to Kapustin Yar and other places.
Not aware of Russian aircraft ever overflying western territory except Open Skies flights.

I’m quite happy with the thought that the west do this more than Russia do. Geography plays a part in that.

It is all a game.

Daniele Mandelli

And just to add, not trying to lecture.

I know you know all that Mark.

Mark Franks

It was a joke. Look a bit of healthy overt spying helps keep the peace the Russkis know what we are upto as soon as we get airborne as we do about them. Its an overt form of snooping and these sorts of missions publicised in the public domain to prove we still have a bogeyman to to look out for. Its the shenanigans you don’t hear about that should worry you. I have a little bit of authority on this subject as I spent 25 years of my life doing this sort of thing.

Daniele Mandelli

I have a little bit of authority on this subject as I spent 25 years of my life doing this sort of thing.”

Acknowledged. Which is why I added that extra comment. That much is clear by your other comments when you post.



A few years back, I (and a few others from my unit) were tasked to escort a visiting group of Russians as they checked to see if we had hidden any nukes inside our camps. As it was this time of year, they were more interested in Xmas shopping than looking for Nuclear missiles

Mark Franks

Yep thats about right.


Actually this operating is massively more sophisticated than anything the Russians can fly over the North Sea.


I think this is part of an ongoing RAF operation incorporating Sentinal and Airseeker as well as typhoons to test and counter Russian S400 batteries in the Kaliningrad area. They did the same over the Black Sea. While the RC135 is carrying out ELINT the R1 is imaging the S400 batteries on the ground also working in conjunction with the Typhoons using their praetorian DASS to Geo locate the S400 radars.


Wasn’t there an article on here recently that they might be coming out of service soon……


Yep, an incredibly useful capability that many of our allies really value but the fleet is due to be withdraw, i believe by 2025 with no replacement. Sums up the state of British procurement sadly.

Poseidon would be a good ISTAR platform with a different electronics and radar suite but we’d need additional air-frames given how hard worked our paltry 9 are going to be conducting maritime patrol.


Challenger is correct that is going out of service, however the final aircraft will be withdrawn by March 2021 not 2025.

Daniele Mandelli

They were meant to be deleted in 2015 SDSR. Then were reprieved.

Such a niche capability that few possess. This is the sort of capability we should keep IMO, although posters like GHF did explain why they might decide to remove them given their vulnerability.

I still remember their predecessors, the CASTOR ( Corps Airborne Stand Off Radar ) Canberra and Islander trials aircraft, when BAOR was looking at the idea.

So I was thrilled when Sentinel arrived and gutted it is leaving service.

Supportive Bloke

Whilst they are vulnerable in a hot situation they a really there to Hoover data prior.

Given the sensitivity of the kit on board they don’t exactly need to be on top of the location anyway.

Glass Half Full

Hi Daniele, just to clarify. My previous comment was just wrt Sentinel not wrt Rivet Joint. I am not aware of an early OSD plan for RC-135. But, you’re correct that the main point is that Sentinel can only be a pragmatic battlefield surveillance aircraft in a permissive environment such as counter insurgency or total destruction of an adversaries IADS. It would be unlikely to survive over or near a battlefield against anyone with high altitude air defence weapons. So then we have to justify its retention and upgrade costs for peacetime or insurgency roles only, especially as we also… Read more »

Daniele Mandelli

Morning GHF.

I know.

Good you posted again, gives greater, more detailed context.

( I still want Sentinel retained! 😉 )

Daniele Mandelli

Yes, I read some time back F35A’s of the USAF also flew in conjunction with RAF Rivets in the area.

Kari Reinikainen

Did one of the aircraft land at Helsinki, Finland? My native country- whose Independence Day is today- is member of Joint Expeditonary Force, if I recall the name of the UK led grouping right, so a visit to Helsinki would not be surprising.