Avro 721 Shackleton MR.5

[Weaver]

Re the Sea Skua - the idea there was, as you say, for small boat picking, such as drug/weapon runners, Iranian Boghammar boats etc, looking at a Sharjah or Aden-based machine.

The principle intended targets were Soviet Osa and Komar class fast missile boats armed with SSN-2 Styx AShMs and defended by radar-controlled 30mm cannons. Two Egyptian Komars had just sunk the Israeli destroyer Eilat, to the general alarm of navies and delight of small shipyards everywhere. The Royal Navy (pioneers in the use of small helicopters from frigates) suspected that a helo-launched AShM might be the answer, so they bought AS.12s as a stop-gap and some FPBs for training and trials. The Lynx was being designed as the Wasp replacement at the time anyway, so Lynx, Seaspray and Sea Skua all developed together. Sea Skua is just small enough to carry four on a Lynx, just big enough to sink an Osa (it can cripple a bigger vessel but would struggle to sink it), and has just enough range to allow the Lynx to stand off beyond effective AAA/MANPADS range. The SARH guidance makes all this possible by being significantly smaller, lighter and cheaper than Exocet-style active radar.

Sea Skua has been carried operationally by various navies' Lynxes, Gernam Navy Sea Kings and Kuwaiti patrol boats. It's been trialled on many platforms, perhaps the most promising being the BN-2T Defender (military Islander) which is effectively a 'fixed wing Lynx'. Fitting it to larger aircraft is generally seen as pointless, since if you can carry a bigger missile to sink bigger ships from a longer range, without the need to illuminate the target, then why not?

Sea Skua's principle competitor in the market was/is the French AS.15TT, which closely resembles it in size and capability, having come out of much the same thought process. The principle different is that the AS.15TT uses radar-command-to-line-of-sight guidance, where the helo radar tracks the target and the missile and sends steering commands ot the latter via radio. The usual carrier is the Dauphin helicopter equipped with Agrion radar.

[kitnut617]

The Nomads were an option, but what is shown in the 3-View are R-3350's

You are now buying in on a whif.     
The Shackleton association will enlighten you..

Erm! that's where I got the 3-View from Pelle     An association member even built a model of it 

https://www.thegrowler.org.uk/avroshackleton/mark-four.htm

It is an awesome site, isn't it? I spoke to Mr Styles replacement about the radar (see earlier in this thread) and also on the model. As far as I could understand, the R-3350's was one of several alternative suggested power plants, of which only the Nomad option was ever studied more closely. I think that was a pity - had they gone for a turboprop, the chances are pretty high that they never would have needed the Nimrod. The P-3A Orion entered service in 1962, and its basic airframe is still doing the job, and not only for third world customers (if you don't consider Germany having deteriorated badly over the last few years.. ). As the MR.4 was essentially an entirely new aircraft compared to the MR.3, a more longsighted power plant choice maybe would have created a serious Orion contender.

Anyway - the MR.4 of Mr Styles is magnificent and not something I am aiming to replicate. I'm more adhering to the Japanese thinking when they deferred the expense of the Orion, preferring a substantial upgrade/rebuild of the Neptune. I shall return to this within the scope of the backstory. There is a thought behind the madness. 

Mr Weaver, Sir! Re the Martel control system antennae - thank you! This was really good information, and exactly what I needed. 

Re the Sea Skua - the idea there was, as you say, for small boat picking, such as drug/weapon runners, Iranian Boghammar boats etc, looking at a Sharjah or Aden-based machine.
In any case, I think the Martel will fit my timeline and the more North Atlantic paint scheme I chose better, so there we are. 

Yeah, I found it years ago. It was not long after I got six Frog Spawn Shackletons from a Hannants sale and I decided to build as many different versions as I could. Since then I got a Sanger MR.1, two more Frog Spawn and a new tool Airfix MR.2. Not to mention a bucket load of Aeroclub parts and decals to convert the Frog based kits into other versions. Mind you, the Avro Nottingham project bit into the stock of the kits.

[Pellson]

Alright. All Sunday, and I haven't even gotten round to add the decals. As a matter of fact, I have stumbled on the decal bit as I did find some decals I'd thought was lost, and they kind of change the possibilities a bit. Well - I'll start with the backstory, then, making room for most..

The Avro 721 Shackleton MR.5

Already as the Shackleton MR.1 entered service in 1951, it was understood that the main problem with the new aircraft would be its power plants, the thirsty, maintenance intensive Rolls Royce Griffons, who were driving contra-rotating propellers that in addition to some thrust, also produced a very distinctive and unbelievably loud noise. Both the MR.1 and the significantly improved MR.2 entering service only a little more than a year later, suffered from inadequate noise insulation in the cabin, leading to an almost certain high tone deafness developing among its aircrew. In operation, the Griffons would further need complete engine head overhauls every 400 hrs and many missions had to be aborted prematurely due to an engine having to be shut down over some mechanical malfunction. Any normal work week in a squadron would include at least one engine replacement. Also, the aircraft handling, both when airborne but in particular on the ground, left something to be desired.
To mitigate this, Avro tried to update their design, and the following mark, the MR.3, replaced the tail dragger configuration with a more contemporary tricycle landing gear featuring twin wheel bogies all round. The noise insulation was further improved and a proper galley was introduced as was an improved crew rest area with a few bunks. The wings were altered a little, increasing the aileron area significantly to enhance controllability and the cockpit glazing was totally changed to significantly improve the pilots view. While alternative power plants were studied, in particular the turbo compound Napier Nomad, nothing came out of it and the Griffons would have to carry on, thus not really removing the main source of the troubles plaguing the design. Despite this, 21 aircraft (serials WR970 – WR990) were ordered as an interim measure.

In the meantime, Avro had been working on a new version that not only would do away with the maintenance intensive and loud Griffons, but also generally improve on other systems and crew comfort as well. This was the Avro 719 Shackleton Mk.4. This was an almost entirely new aircraft, with very little resemblance to its predecessor but for the common nose configuration. Behind the nose, it featured a new, circular fuselage of larger dimensions all over, longer wings and an entirely new tail empennage featuring a large single fin in place of the WW2 vintage twin fins of the earlier marks. Its larger size meant longer endurance and more space for equipment and systems, but also higher cost. Most crucially, it relied on the ill-fated Nomad engine, and when that finally was cancelled in 1955, the cost of redesigning the already very expensive Mk.4 to accept another, not yet existing power plant was seen as prohibitive.

Initially, RAF now turned to the pan-European talks that eventually would result in the Breguet Atlantic, but not much came out of it, and the Britons soon withdrew, mainly for cost reasons. Instead, RAF Coastal Command, increased the MR.3 order by 13 further airframes (serial nos XF700 – XF712). Later, a third batch of five was added (XF730 – XF734)
But this was a short term measure, RAF being very much aware of the increasing submarine threat from the Eastern bloc. Avro however hadn't given in, and in 1956 proposed a redesign of the existing Shackleton MR.3, more intimately based on its predecessor but still with potential enough not only to solve the most immediate problems with the existing aircraft, but also to build on until an entirely new aircraft could be developed and introduced, this being foreseen for the late 1960s. This was the Avro 721 Shackleton Mark 5, or MR.5 as it became known when RAF bought in on the idea. It shared wings and most of its fuselage with the existing MR.3, but the engines were replaced with a smaller derivative of the Bristol Proteus turboprop engine now in final development. The new engine, named Bristol Prometheus, rated at just below 3000 hp, meant a significant increase in power in comparison to the old Griffon. This was welcome as weight creep had set in on the MR.3, eventually necessitating installation of additional Viper turbojets in the rear of the outer nacelles to be used for take-off. In addition, the new engines weighed significantly less that the Griffons, and together with the deletion of the cannons in the nose, some internal changes and the reintroduction of a magnetic anomaly detection system at the very rear of the aircraft, it altered the centre of gravity significantly. To compensate, the wing was moved four feet to the rear. This was accommodated by simply shifting some components around, as the fuselage itself held a constant cross section throughout the mid-section of the aircraft, save for the bomb doors.
In addition to above, new somewhat larger stabilisators replaced the old units, albeit placed in the same location as before, but the twin tail was gone, replaced by a large single fin derived from the Mk 4 project. Internally, the opportunity was taken to redesign and improve both noise deadening and climate control, now providing both enough heating in cold climates and cooling in hot. The old marks had been legendary for being ice cold up front and sauna warm further back.

As previously mentioned, the nose mounted guns were now gone, but in their place, two hardpoints rated for 1500 lb each were installed under each outer wing, allowing rockets to be carried in addition to bombs, depth charges or torpedoes. All in all, a combined weapons load up to 20.000 lb could now be carried under max load conditions.
Avro took MR.3 XF712 off the production line later the same year, quickly modifying it to MR.5 configuration. This prototype flew already late in 1957, even before the majority of the MR.3's had been delivered. It was generally perceived as a success, but some concerns about the main wing spar integrity had arose due to the higher torque from the new engines.  However, this was soon solved, and as the flight tests had been allowed to carry on in the meantime, results were soon obtained that convinced Coastal Command of reordering the second batch as MR.5's rather than MR.3's. In this process, the third batch was increased by a further ten aircraft (XF735-738, XF740 – XF745) bringing the total number up to 28.
As the structural changes mainly consisted of shuffling things around, delay in delivery was only about a year and the first MR.5 (XF700) was delivered to no 201 Sqn in December 1959. The other followed during 1960-1961.

The Prometheus engine had now matured and its output had increased to 3850 hp (equivalent), adding even more growth capacity. The aircraft could now patrol on two engines, having the outer pair shut down and its propeller feathered to save fuel and increase patrol endurance. Also, as the new power plants were much more silent, the crew fatigue problems were all but gone and the MR.5 was quickly embraced by its crews. The Prometheus also soon built its reputation as a very reliable power pack indeed. As it turned out, in the more than thirty years the MR.5 flew, not one mission had to be aborted due to engine failure, and no engine had to be replaced out of ordinary maintenance schedule. A remarkable feat in its own right, but even more so when remembering the Griffon-related troubles.
In 1962, the Americans put the P-3 Orion in service, and while that bigger aircraft quickly set a new standard, towards which the Nimrod was to be developed, the Shackleton MR.5 was able to keep on top of the game due to repeated equipment upgrades and very proficient crews. Based on results, the RAF Shackletons were much looked up to internationally, even by the Orion crews. Having seen Singapore-based Shackletons first hand in an ASW exercise in 1961, the Japanese Self Defense Forces even chose to modernise their P-2 Neptunes approximately along the MR.5 lines rather than buying new, much more expensive P-3 Orions.

Smaller and bigger systems upgrades continued to improve the efficiency of the MR.5 during the following years. As the old MR.2's became increasingly weary, and it stood clear that the Nimrod still was a decade away, another 37 (serials XS130-XS148, XS190-XS208) were ordered in 1962 for delivery during 1964-1965. Most of the upgrades happened on the inside, but in 1968, a fin top fairing was added carrying ESM and ECM equipment, and in 1972, the Martel missile was integrated, missile communication link antennae being located in the wing tip tanks. As the brand new Nimrod slowly entered service from 1973, Shackletons still remained active in parallel with its younger and bigger sister all the way up to 1990 when the last MR.5's finally bowed out as a result of the end of the Cold War.

What do you think? Works?

[NARSES2]

Works for me sir 

[Old Wombat]

Yep!

[kitbasher]

 

[Rheged]

That, sir, is a backstory I would have been proud to have created!!  I am most impressed.

[McColm]

I would have gone for a flattened nose to improve visibility for take off and landing. I have done this several times and it works. An arrestor hook for short landings works as well.
The MR.1 did have inflight refuelling plumbed in but never used it operationally, so that's another option.
Viper jets were fitted to the two outer engines on the Shackleton but it's your build so you can add whatever you like to It.  An ECM jammer pod would have been fitted at a later stage ,did you add the flare chutes?
Great back story.

[PR19_Kit]

LOVE the backstory, very logical indeed. 

The MR1's flight refuelling system was of the 'Looped Hose' variety, and the reason it wasn't used is there were no tankers that used it at that time.

And with the Prometheus engines the MR5 wouldn't have needed the Vipers as the main engines were already powerful enough according to the backstory.

[Pellson]

That, sir, is a backstory I would have been proud to have created!!  I am most impressed.

That's about the best grade I could have hoped for, from the Master himself. Thanks. 

[Pellson]

Decals are on, and I'm pretty pleased as well. In the end, despite finding decals that would have matched the original Shack scheme properly, I elected to stay with a somewhat later and definitely much more hot war influenced scheme, and I think it went down well. There are now decals from the Shack kit itself, from my general RAF roundels stash and from an unfortunate old Airfix Red Arrows kit, some forty years old. But it looks good.

However, having added the Future coat to seal the decals in, I realised I was out of my go to Humbrol matt varnish. Digging through the paint drawer though, I found a tin can of Revell varnish that I for some reason had abandoned a long time ago.
Now I realise why I did just that.. 
The stench throughout the house is outrageous, and it didn't even cover properly.

Ah, well..  it's a slow drying paint, but eventually it'll be dry enough to have a second coat of the Humbrol stuff I in despair went out and bought yesterday. Until then, it's sitting in a cordoned-off room with a lot of open windows. There it can smell itself green, if it wants to.. 

[Old Wombat]

A green Shack?

[Pellson]

Final bits and bobs on, missiles hung and touch ups done. Time to move this to the "Completed" section, then.

It's been a fun build, actually, and I'm pretty chuffed about it. The old Frog kit was always somewhat daunting a project to take on, but as things have progressed, I'm pleasantly surprised by how nice it has been building up. Also, this is my first ever group build, and finishing in time (even within the original time limits, no less) has been an entirely new, if somewhat mixed experience. I'm not absolutely sure I'll do it again, as it does take away from the totally lust-driven building I usually prefer. On the upside - I actually completed a pretty major project without leaving it to mature for a year or two on the Shelf of Doom^TM. That's a very substantial diversion from the usual glacial build pace. It actually brings hope that I'll complete more than the odd few percents of my Stash^TM before I kick the bucket. An interesting perspective indeed.

If I had the faintest idea on how to link the Completed thread, I would. As I don't, I'll post a copy of the post here as well in due time. Easier for me to find in a year or two, methinks.. 

[Pellson]

Thanks to Chris's kind support, I'm adding a link to the "Finished Builds" thread here, rather than copying it all.

https://www.whatifmodellers.com/index.php?topic=49280.30

[Rheged]

That, sir, is a backstory I would have been proud to have created!!  I am most impressed.

............and I am equally impressed by the finished model. 

Overall, this is a magnificent piece of work.