A salute to the Sentinel

[canberraman]

On 26 February 2021, a Royal Air Force Sentinel R.1 aircraft – serial ZJ694 - carried out the last operational flight of the type from RAF Waddington after 14 years of service. The five Sentinel aircraft and V (Army Cooperation) based at RAF Waddington will be retired and stood down respectively on 31 March. 

The Sentinel R.1 aircraft have flown circa 32,300 hours conducting approximately 4,870 sorties – mostly on operations, during its service life. The withdrawal from service was first announced as part of the 2015 Strategic Defence and Security Review. The UK continues to invest heavily in NATO ISTAR capabilities, not least Maritime Surveillance (Poseidon), Airborne Early Warning and Control (E-7 Wedgetail), Armed ISTAR (Protector), Rivet Joint and Shadow – all of which have either entered service or will do in the near-term.

The genesis of the Sentinel programme goes back to the early 1980s, when the UK government identified a need for a battlefield reconnaissance system to provide awareness over a broad area.  Expressed in the Corps Airborne Stand-Off Radar (CASTOR) requirement, the programme elicited responses from Thorn-EMI and Ferranti.  The former’s radar was tested in an English Electric Canberra from 1982, while a Britten-Norman Islander modified to take the latter, first flew in 1984.

By 1988 the programme had become ASTOR and, with a Thorn-EMI radar installed, the Islander flew low-altitude trials examining its compatibility with the USAF’s prototype E-8 J-STARS (Joint-Surveillance Target Acquisition Radar System).  This work was part of a definition phase which, it was hoped, would enable a contract award in 1994.

Finally, in 1999, Raytheon was contracted to develop a five-aircraft ASTOR system, using Bombardier’s Global Express business jet as the airborne platform, and basing the mission system on its ASARS-2 radar, developed for the USAF’s U-2.  Raytheon took a first Global Express for modification in 2002 and re-flew it with the ASTOR system installed in May 2004.  Initial aircraft deliveries were made in 2006.  Service trials began in 2007 and V(AC) Sqn flew the first operational Sentinel R.1 mission in November 2008.
The aircraft immediately proved its worth on Operation Herrick over Afghanistan and again during Operation Ellamy in Libya in 2011, becoming a vital link in the chain of target identification and prosecution, especially where fleeting or ‘pop-up’ targets were concerned.  The 2010 Strategic Defence and Security Review nominated Sentinel for withdrawal as soon as the Operation Herrick commitment ended, but such was the system’s value to British and allied commanders that it was given a reprieve.  It continued to prove its worth in Operation Shader (Campaign against ISIS), and closer to home, the squadron also provided support to the civil authorities in 2014 during the UK's flood emergency in southern England (Operation Pitchpole). However, following the 2015 Strategic Defence and Security Review, the out of service date was finally set for end of March 2021.

The five aircraft delivered to V (AC) Sqn were given serials ZJ690-694.  In recent times just three aircraft have been operational with ZJ690 stored at Waddington, and ZJ693 at Raytheon Systems Ltd at Hawarden.  In 2020 expressions of interest were being sought by the MoD from “companies wishing to purchase the five Sentinel aircraft and spares for teardown to harvest all reusable parts for potential resale, recycling or disposal and final cutdown and removal of the remaining platforms”, but that “these aircraft are not for re-use”.
Sadly we won’t see a Sentinel in the RAF Museum; it’s earned its place. It is highly like though that as one of the RAF most senior squadron, V (AC) will return though perhaps as a Protector operator.

Here is a selection of images from throughout the type’s relatively short but illustrious RAF career. 

 

First public appearance of the Bombardier Sentinel R.1 was at the Waddington International Air Show in June 2006 where these two photos were taken. This photo shows newly delivered ZJ692 looking pristine, but lacking the squadron fin markings that were initially applied to all the fleet.

 

 

 

The Waddington home team.. This three ship of Nimrod R.1 , Sentry AEW.1 and Sentinel R.1 opened the flying display at the Waddington IAS in 2007 and demonstrated the station's growing ISTAR hub capacity.

 

 

Also from 2007, two views of ZJ690 at Waddington in July that year, in full sqn markings including a closeup of the V (AC) fin marking.

 

 

 

ZJ694 about to depart on a mission from Waddington in June 2011.

 

 

From the 2011 Waddington IAS, ZJ694 in the static display.

 

 

2013 marked V (AC)’s centenary. To mark the occasion this commemorative t shirt was produced for the squadron showing the Avro Type E – their first mount in 2013, through to the Sentinel of 2013. 

 

 

 

Sentinel ZJ692 also received special fin markings to celebrate the squadron centenary as seen at Waddington IAS in June that year.

 

 

The maple leaf in the squadron badge - approved by HM King George VI in June 1937, commemorates the Squadron's close links with the Canadian Corps during WWI.

 

 

Sentinel ZJ692 was joined by the Red Arrows to celebrate V (AC)’s first 100 years and to open the flying display at Waddington IAS 2013.

 

 

From around 2013 the squadron markings began to disappear from the Sentinel fleet presumably due to the aircraft being deployed so often in real world combat ops.  Also, the matt camouflage grey paint scheme finish was replaced by a high gloss finish which is easier to maintain. This photo depicts ZJ692 in the anonymous new livery at Waddington in 2014.

 

 

ZJ692 once again, this time arriving for RIAT 2018 at RAF Fairford.

 

Hope these have been of interest. 

 

Mark

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Dave Swindell]

17 minutes ago, canberraman said:

Hope these have been of interest. 

Definitely - I've got the Anigrand kit in the stash to build sometime. Thanks very much.

[Team Aer Lingus]

Outstanding pics of to my mind a very pretty & capable aircraft. 

 

 

Thanks for sharing as always Mark

 

Eamonn

[Red Dot]

Well done Mark. Very interesting to read

 

Andy

[Des]

A lovely looking aircraft and thanks for sharing.

 

Had the opportunity to get close-up to the Sentinel on a few occasions during photo-ops for various exercises - no photographing through the open crew door or on other occasions no photography at all if the crew door was open - although all I ever saw was grey padding on the fuselage wall and a grey curtain separating the cockpit from the cabin.      There was no restriction imposed the last time I saw one on an Airshow static line-up , just could not be bothered with the jostling involved to get an angle to take the photograph.

 

One of the first times I was given the photograph/no photograph brief on the Sentinel my response to the media escort was 'there's probably only a couple of guys inside up the back playing on a X-Box' for which I got a very strange look.      Not long afterwards one of the UK TV News Channels broadcast from a Sentinel during a mission over/near Libya which did indeed show a very bare cabin with a couple of guys sitting up the back at a computer terminal.

[spruecutter96]

I wonder how much money our politicians flushed down the toilet by cancelling this aircraft? I'm sure it could have served for decades more and been extremely useful with it. What future conflict will its cancellation create a major information "hole" in? 

 

Chris. 

[canberraman]

Thanks everyone for the comments and likes - much appreciated. It is sad that another capable type is leaving the RAF inventory prematurely and Waddington will likely become a much less interesting and active place to visit.

 

Mark

[Evalman]

Sad that they are being retired early. Very nice selection, thanks for posting. 

[Alpha Delta 210]

Thanks very much for the interesting photo-essay, Mark. Another type that I have been guilty of largely ignoring and then wishing I had paid more attention to.....

[Muzz]

A good read Mark, thanks for posting, enjoyed the photos too! I always thought the Sentinals were an UOR, purchased and rushed in for Op Herrick, clearly not the case from reading your text.

 

Murray

[Adam Poultney]

Shame I didn't get to see them more

 

 

[Bangseat]

Thanks @canberraman, great write up. I personally find it hard to grasp exactly what these platforms do - Rivet Joint particularly - but they are obviously strategically vital. I just hope their retirement doesn't leave us with the degree of capability gap we had in 1982 in maritime AEW. 

[canberraman]

2 hours ago, Bangseat said:

Thanks @canberraman, great write up. I personally find it hard to grasp exactly what these platforms do - Rivet Joint particularly - but they are obviously strategically vital. I just hope their retirement doesn't leave us with the degree of capability gap we had in 1982 in maritime AEW. 

Hi Bangseat,

ISTAR is a quite complex subject and each platform involved does have different but sometimes overlapping roles. From the RAF website it says about the Sentinel:

 

The Sentinel R.Mk 1 provides long-range, wide-area battlefield surveillance, delivering critical intelligence and target tracking information to British and coalition forces.  The aircraft has been operationally deployed in support of operations in Afghanistan, Libya and Mali, and is currently deployed in support of British and Coalition operations in Iraq and Syria. Using its powerful multi-mode radar, the Sentinel’s mission crew identifies, tracks and images numerous targets over great ranges, passing the information in near real time to friendly forces.  A team of intelligence imagery analysts from 1 Intelligence, Surveillance, Reconnaissance (ISR) Wing backs up the Sentinel crews, conducting in-depth forensic analysis of collected data, and using it to generate intelligence products for time-critical dissemination to commanders and decision makers, enabling them to execute current operations and plan future strategies.  

 

In a nutshell it is like an AWACS for ground based threats and targets and passes real time information to commanders in the field or to allied HQs. 

 

Rivet Joint on the other hand is a Signal Intelligence (SIGINT) gathering platform. It 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 to derive intelligence for commanders.

 

Obviously much of ISTAR is classified but clearly it is an important capability that much has been invested in and will continue to develop with new platforms arriving in service or planned.