The Ministry of Defence say it remains confident that Merlin Mk2 helicopters fitted with the CROWSNEST early warning system will be available to support the first operational deployment of HMS Queen Elizabeth in 2021.

Stephen Morgan, the Shadow Minister for Local Government, asked via a written Parliamentary question:

“To ask the Secretary of State for Defence, whether the Crowsnest radar system will be operational when the Queen Elizabeth Aircraft Carrier deploys.”

James Heappey, the Parliamentary Under-Secretary of State for Defence Procurement, responded:

“The Ministry of Defence remains confident that the Merlin Mk2 helicopter, fitted with the Crowsnest system, will be available to support the first operational deployment of HMS Queen Elizabeth in 2021.”

In 2017, Lockheed Martin was awarded a £269m contract to deliver the Royal Navy’s CROWSNEST Airborne Surveillance and Control (ASaC) programme. As the prime contractor, Lockheed Martin is responsible for the overall design and development of CROWSNEST, which will provide a vital surveillance capability to support the Royal Navy’s new Queen Elizabeth Class carriers.

CROWSNEST uses a high power radar to provide long-range air, maritime and land tracking capabilities that will ensure early detection of potential threats and vital surveillance for the entire fleet.

This capability will be role fitted onto the Merlin Mk2 helicopters and deployed in support of various Royal Navy vessels including the fleet flagships HMS Queen Elizabeth and HMS Prince of Wales.

Lockheed say that CROWSNEST incorporates an updated version of a Thales Searchwater radar and Cerberus Mission System which are deployed as role fit kits along with the Merlin Mk2 helicopters.

This will allow the Royal Navy to adjust the configuration of the airframe depending on the mission.

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Question: could an AWAC version of the Osprey be developed? QE can’t operate a Hawkeye so I understand the requirement of something else but if the Osprey could be developed for the role then would it not be a better solution than a helicopter?


there was a proposal for one, but then who would fund its development?

Steve Taylor

It would be a waste of money when we can’t even afford more Merlins.

I would prefer money to be spent on upgrading Crowsnest’s radar.

And if we were to look at another aircraft for the system I would look to Chinook.

In a world with better budgets yes it would be sort of obvious choice.


Interesting idea. I hadn’t realised that the service ceiling of Chinook is 5,000 ft higher than Merlin. 5,000 ft lower than Osprey but still a worthwhile improvement in a role where altitude is so important and it is an aircraft we have in service. It also has a big payload capacity. If it could also host the roll-on/roll-off AAR kit that the USMC is developing for Osprey would Chinook have the speed to be able to be a platform for that as well? In fact with (I believe) the Chinooks bigger payload capacity vs Osprey it could even potentially carry… Read more »


As much as I love the Chinook, it would have a few issues and a few benefits: 1. Granted the Chinook could fly higher, the crew will still need to be on individual oxygen sets as the aircraft is not pressurised. 2. The aircraft does not have folding blades, so would take up a lot of deck space. Boeing have investigated designing a rotor head that will allow the blades to fold. However, because of the CH53, there has been no market for it. So we would have to pay for the development costs. 3. The aircraft when empty or… Read more »

Steve Taylor

Space is the one thing QE isn’t short of……

I wasn’t saying move to Chinook I was saying in preference to a hypothetical never to happen ever move to MV22.

A Chinook with folding rotors would be a competitor for CH53. The latter is bigger yes, but the former is more numerable and cheaper.

comment image

I am not really interested in AAR for F35b only Crowsnest.

And I was thinking of something Kamov-esque.

If more we no object then yes MV22. We need more Merlin. Simple as that.

BV Buster

What sort of witchcraft is this? you posted an image!!! how….the ….FU…….?

The Power of Christ Compels You,The Power of Christ Compels You,The Power of Christ Compels You!!!!!



Good photo – how by the way? This was a trial on the QE about a year and half ago, to make sure a Chinook could fit downstairs. What the photo doesn’t clearly show is on the forward head, the blade is still attached and pointing forward. With a Chinook you have a choice of having a blade on the forward pointing forward or a blade on the rear head pointing backwards. The Chinook’s rotor head design is different to that found on its baby brother the CH46 Sea Knight. To fold the blades on a CH46 it uses electric… Read more »

andy reeves

any in flight entertainment?

Mr Andrew J Poulton

Chinooks are not marinised and it’s a significant job (expensive). Thye’re OK for very short term use as I understand it but long term, marine deployments are a no no


I wouldn’t bother with Osprey, better one of its successors, the V-280 Valor or B-247 Vigilant.


Are they not complimentary to the Osprey, both being smaller? But agree in one sense – the V-247 seems an obvious choice for carrier-borne AWACS.


The Osprey is 20 years old, expensive to buy and maintain. The Valor incorporates a lot of lessons learned from designing and operating the Osprey. (Plus it has an autonomous mode too.) Will be interesting to see if the US Army chooses it for it future vertical lift requirement. The RN previously looked at the EV-22 an Osprey variant for airborne early warning but previously rejected it. Presumably the cost of training and supporting a new airframe was the deciding factor. Given a general purpose drone capability would be useful, even when we eventually have a full complement of F35s,… Read more »


That would be the logical course. So probably unlikely.


Well by the laws of chance the MoD has to make the correct decision every once and awhile by pure accident 😉

Levi Goldsteinberg

If Crowsnest is a bolt-on, could it be fitted to fixed wing?


The only fixed wing aircraft that can operate from the QEs are VTOL aircraft. We’ve none except for the F35. A newer tilt rotor aircraft would be a major improvement on using helicopters.


Thought this was meant to be the low risk option and utilised work /kit? by the older Sea Kings. So what is the real problem?


Agreed MadMatt, there’s no real reason why this shouldn’t be ready for carriers’ operational deployment. In fact, it should have been one of the first air systems tested and certified on the ships. The Crowsnest concept was agreed upon from the early stages, and should have been low risk, featuring a similar concept to the previous Sea King ASaCs, an airframe (Merlin) in longstanding use by the RN and the donor radar set being from the existing, in service radar (Searchwater). They knew when the carriers were supposed to be coming into service, so that should have been the target… Read more »


i cant understand why its a role fit option. we need at least 5 helos per carrier to provide 24 hour surveillance, thats 10 helos plus a training flight. in addition the helo needs long range fuel tanks to enable it to remain on station for 4 hours. That really impacts on the ASW role of the Mk 2s. which is its main purpose on the carrier. Also are the same aircrews expected to role change between ASW and ASaCS? i THINK NOT. We need to resurrect 849 squadron and have dedicated Merlins. 15more would be nice.


Same; I didn’t even realise this capability was gapped? I could’ve sworn it was meant to role right in to being operational after SKASACS?


I think the QEs will be flying a tiltrotor based AEW platform as soon as partners emerge to spread the costs around…


Steve Taylor

Who? The Italians already have Merlin AEW. The Japanese and Koreans?

There is nothing wrong with what we have got. Apart from the better radar would have been nice. And single purpose airframes and more of them.


Survivability of course! In AEW altitude and endurance are critical to see as far out as possible and remain there without break. In the USN, the Hawkeyes are the first aircraft to launch and last to recover. That was one the lessons of the Falklands for the RN – the limit of radar coverage with the Sea King based radar. The USN version of the Osprey has a much higher altitude capability and much greater endurance than the Merlin. It can also be used for that critical AAR mission as well Remember, one of the points of the upcoming defense… Read more »

Paul Bestwick

The Sea King based AEW was developed as a result of the Falklands campaign. There was no AEW in the Falklands, hence the use of T-42 and other destroyers as pickets.


You’re absolutely correct Paul, I wrote that badly.



Actually the Italian Merlin ASH (AEW) was a failure. They’ve been hangared for some time now. They tried to do it on the cheap.


Crowsnest should suffice for now but long term we will probably be looking to miniaturisation onto a drone platform rather than Osprey in conjunction with cheap Ultra-low LEO satellites.


The radar on the T46s are supposed to spot targets, multiple targets, at huge distances, aren’t they? Is crowsnest that much better? I suppose it is!


No, Crowsnest is not better than Sampson, far from it. For starters Sampson is a minimum of 20 times more powerful. It has more space on the ship allocated for signal processing and cooling. But more importantly the issue with any ship’s radar is the relative radar horizon, which is fixed dependent upon the height the antenna is mounted above the waterline. Crowsnest by comparison has its radar mounted to the side of a helicopter, which can fly at 10,000ft. Thus its relative radar horizon is leagues further than the T45’s Sampson. The Merlin’s Crowsnest is hampered by the relatively… Read more »

Rob N

The searchwater used in the Crowsnest is not that advanced, it is not an electronically scanned phased array and is not in the same class a Sampson. However all it really needs to do is to provide over the horizon targeting data for Sea Viper and F35 intercept. This is so that Sea Viper can use the full reach of tge ASTER 30 to kill fast sea skimmers early. Rather then a better lift platform for the AEW money should be spent on updating the radar to cope with fast stealthy targets. I suspect the current radar choice was political… Read more »


This is one of the major issues with the Searchwater radar. Granted it has provided good service over the last 20 years and shown it was capable operating in environments such as Afghan, where it was never intended. The original Searchwater fitted to Nimrod operated in the X band and had a maximum range of 200nm, it was originally designed to find submarine periscopes hence the high frequency. Over the years the signal processing was improved so it could do different modes. However, its range never really got much better. This was because it had a smallish antenna, limited by… Read more »


Wouldn’t the idea be to rely on the T45’s radars for long range detection of aircraft and the Merlin’s Searchwater for its look down capability to spot sea skimmers in rough seas.


Its all to do with the radar horizon. The T45’s Sampson is about 50m above sea level, which gives a relative radar horizon of 25.3km or 13.66nm. If we draw an imaginary line from the Sampson to the horizon, then extend it to space, everything below this line is blind to the Sampson. This is why we need a radar that is flying up near 10,000ft to move that horizon further back. We have established that the Searchwater radar on a good day has a maximum range of 200nm, as published by the manufacturer. Designed to spot periscopes, it uses… Read more »

Rob N

Would there be scope for a antenna carrying blimp/sir ship to give persistent OTH coverage? What about Zephyr?


The Zephyr unfortunately cannot carry a radar that has over 200nm range. The Zephyr 8 for instance can only carry a 5kg payload. You would have to significantly scale up the airframe to carry something that weighs over 200kg and still be able to reach 70,000ft. Then because the wings would be so long there would be serious issues manoeuvring it on the ground. I think the high altitude hybrid airship is probably the best answer. It could carry two radars protected within the envelope. It would also have the speed, range and duration to shadow a fleet. The US… Read more »


What do you mean by ultra-low LEO? For anything to be at all orbital it would be whizzing past at Mach 20ish…so in a ship’s AOR for about 4 min tops. And pseudo-sats might have satellite in their name, but are nowhere near LEO.


Several countries are working on developing the tech for Constellations of radar satellites working about 200-400km up, they would be over the target for about 10 minutes every 75-90 minutes and so by building a constellation can provide near continuous wide area coverage, spotting things before-they get close to a carrier group for example, or monitoring ground targets like mobile launchers.

The US for example has revived the defender 2 programme.


Gotcha, although never seen it referred to as ‘ultra-low’ LEO (but it is at the bottom of the maintainable altitude regime). Despite the constellations starting to go up and sensor / data use R&D, I still think we’re at least the lifecycle of an air breathing platform away from having ubiquitous, real-time data to surface asset surveillance networks reliably running.

I personally prefer the idea of pseudo-sats organic to naval assets but again, there’s an R&D wait time.

Jason Holmes

I worked as a Searchwater radar tech on Nimrods in the 2000’s, I had chance to work a little on the MRA4 programme, the Searchwater 2000 is just a fancier 60’s radar with some digital processing, its still capable but it hardly seems to make sense going forward.


I didn’t realise just how old it was. And for the MOD to be passing this off as new kit is ridiculous. In fact buying any radar capability now that isn’t AESA is ridiculous.

Jason Holmes

Its been modernised a large extent, if it hasn’t changed from the developed version for MRA4, its still a single parabolic dish with a non electronically steered beam, using the physical antennae to direct the energy. It was world leading at the time, and has performed all asked for it on the sea king variant. But I seriously doubt its ability to discriminate low profile targets, swarms of UAV’s etc…but it will perform a good basic volume air/sea search function.

Rob N

It looks like jobs for the boys to me. One option was a variant of the F35 Radar but that was rejected!

You would think they would protect their carrier investment by spending a little extra and getting a modern system. You cannot mess around with super/hyper sonic sea skimming missiles. You need an AESA radar!

andy reeves

its seems ages, that we’ve been waiting for it

Phil Chadwick

I’m somewhat surprised by the time it seems to be taking with Crowsnest. I remember how quickly Searchwater was fitted to Sea Kings in 1982… When push comes to shove…


Have the MOD / Navy considered existing STOL transport planes such as Britain- Norman Islander. These have very low stall speeds and takeoff / landing distances – could they land / takeoff on a carrier unassisted by cats / traps if modified or upgraded. I’d imagine these would have longer range and higher ceiling and be more suitable than a Merlin

Daniele Mandelli

Thinking way back, didn’t an AAC Beaver or similar carry the first CASTOR in trials for BAOR? Went on to become Sentinel.


Unfortunately, the Islander doesn’t have the lift capacity to be a competitor for the Merlin. Britten did try to prototype an Islander with a side looking radar, but compared to the Searchwater it was quite short ranged. The other issue with Islander is its max altitude is actually lower than the Merlin’s. So in most respects it isn’t as useful as the Merlin. To operate a STOL aircraft off the QE class it needs sufficient power to supply a decent radar, which is going to be large and heavy. The airframe must be able to accommodate either a single large… Read more »


The new Brit carriers deserve a proper AWACS aircraft that can fly at high altitudes, has a very powerful radar like the E-2D and can get to where it needs fast and stay on station for a long time. A helo can do none of these. Although for most contingencies I would guess the Brit carriers would use either the USN E-2Ds or a land based AWACS aircraft for maximum situational awareness.

Steve Taylor

QE’s should have built around E2 with the bomb truck the secondary consideration. But AEW/ASaC isn’t very exciting is it? They are strike not defence carriers don’t you know!?!? 🙂


Rubbish. The Brit carriers will be the only carriers in the world with an 100% 5th gen fighter air group. Stick that in your pipe and smoke it.

Steve Taylor

I remember you now. The offensive idiot who reads what he wants to read. The chap who can’t add up megawatts if I remember. If a carrier can fly and land an E2 it can fly and land all carrier aircraft available today. Only carriers with a 5th gen fighter group. BECAUSE THICKIE IT IS THE ONLY FIGHTER AIRCRAFT WE CAN FLY. And the few we have only make a group in the lowest terms in that more than 1 of anything is a group. When the Chinese hypersonic missiles comes in through the side it will be a big… Read more »


Wrong again.

The French carrier Charles de Gaulle can operate E-2’s but it can’t operate F-35C’s.

Steve Taylor


You really are one of the most stupidist persons I have ever come across.

Meirion X

The CATs on the CdG don’t have enough power to launch a fully loaded F-35C.

Meirion X

I forgot to say, there have been generation issues with the CATs on CdG in the past.
Does anyone remember what their where?

Meirion X

E2 is very expensive!
The RN would have require a min of 8. Making it as expensive as the P8 program.
I think the RN would have needed to look elsewhere!


Only 9 systems being planned and paid for I believe.

Steve Taylor

Yes. That would be enough for deployment, training, and spares, but there would be little to no spare capacity. Say for example you wanted to cover a second group.


There’s no plan/strategy/aspiration/hope/belief/prayer that the RN will simultaneously operate two carrier groups. If two carriers are ever deployed together, they will be part of the same group.

Steve Taylor

Carriers aren’t the only thing that needs or should be given AEW.


Straws, grasping at.

Steve Taylor

So say an amphibious group won’t need AEW or support group of RFA / STUFT ? Magically they are invulnerable to attack……..


They are if your only AEW is an E-2.


10 not 9

Simon m

I believe aw609 is approx £15 million a pop & once its available why not get SAAB to equip with latest erieye radar equipment. Could likely get 9 for less than £300m. It has higher speed than Merlin, higher/better ops at altitude to other tilt rotors due it being pressurised. Endurance is unclear as the only figures I can find are on doing a flight a to b which is likely to be of higher fuel consumption than a AEW track but minimum is 3 hrs. With significantly faster transit speeds this would be less of a problem. The Italians… Read more »

Lee H

Afternoon All Whilst challenges continue in getting 90’s legacy technology integrated in to modern software (great short term savings at the time but like CAPTOR on the Typhoon will need to be replaced eventually) I would suggest that we are still following a route that is still “a one for one replacement” for a platform without fully working out what we want it to do. The comments above talk about different sizes of airframe to carry different sensor payloads but the real question is “will the CROWSNEST system do all the things the RN want out of it?” We have… Read more »


“I see CROWSNEST as very much an interim step that will deliver something that allows the carrier to get to IOC and maybe limited FOC, but nothing else – its a gap filler”

Please justify your statement by telling us how Crowsnest falls short of the RN’s requirement.

Steve Taylor

You really need banning from this site.

One of the reason why sites like this aren’t taken seriously is idiots like you.

Lee H

Hi Ron Firstly I do not need to justify my statement – its an opinion. Secondly, failing short of the RN’s requirement isn’t actually what I said – stated “it doesn’t reflect what the user is asking for”. However I will try and explain why I think the system will have a limited life. The sensor, the updated Searchwater Radar, has reached the edge of what it can do – its a late 70’s/early 80’s rotating dish that whilst extremely good no longer has a place in the world where AESA type systems are now prevalent. The mission system has… Read more »


Perhaps a better low-cost low-risk solution would have been to integrate the Saab GlobalEye radar system on a Leonardo AW609 – if it would fit. Long endurance, higher ceiling and with a capable, established radar. Could possibly even build them here in the UK. I believe Bell helicopters who co-developed did impose a ban on selling to the AW609 to military customers but I’m sure something could have been agreed.


I can’t understand why you would develop such a costly platform in the age of drones, if you could operate a drone with over the horizon capability you would save a tone of fuel etc and can be operated from the carrier or supporting platforms


Because Crowsnest as well as providing the radar platform, carries the fighter controllers and their consoles. It’s a self contained system with no dependencies on other platforms.

Lee H

No dependencies on other platforms, can you articulate what you mean by that please?

Meirion X

I think Ron means it is a self contained system that can pass on information to either ships or other aircraft.

Meirion X

A drone AEW would most likely be dependent on a ground station or a particular satellite.

Lee H

Morning The drone sensor, or any other sensor for that matter, to be fully utilised, needs to be part of the wider secure network enabled community. This secure fused network works in a meshed nature to deliver information back to a controller, where ever he or she may be. We are moving from a 1980’s model of having airborne short range AEW LOS platforms, like Merlin CROWSNET to a fused network, multiple sensors working together to give, via multiple bearers, information to the user so they can use it to deter or defeat the enemy. We have to move on… Read more »