The P.1121 Scenario

Yellow Palace

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There's been a lot of discussion lately of the 1957 Defence White Paper and the desirability of the RAF replacing its fighter force with a single type. One of the types mentioned is the P.1121. So, what does that look like?

First, a disclaimer. I'm not advocating that this is a better, or more affordable, course of action than was pursued in OTL, or even a particularly likely one. I'm merely exploring what it might look like.

Let's start with some real dates. The P.1121 brochure was presented to the RAF on 12 June 1956. It is therefore impossible for procurement to begin any earlier than this. In that brochure, Hawker claimed that with an instruction to proceed in August 1956, they could have a prototype flying in April 1958 and the aircraft entering service in December 1958.

Given that the English Electric P.1B prototype first flew in April 1957 - a year earlier than Hawker's estimate for the P.1121 - and the production Lightning wasn't being delivered to squadrons until June 1960, I think it's reasonable to suggest that Hawker's projected timeline was optimistic. I can't find a date when the P.1B prototypes were ordered, but the P.1B development batch and the operational F.1 both took about three years from order to first flight.

So. Let's suppose that Air Ministry is convinced by Hawker's arguments for a single-seat fighter, designed primarily for the air superiority role but adaptable to others, and suitable for use in 'small wars'. Such a type would also be a more capable interceptor than the F.23/49 or F.177D, though falling short of the eventual OR.329 type. It is therefore ordered _in place of_ the Lightning in November 1956. This is probably as late as you can order the P.1121 and get it into service as a fighter, rather than a nuclear strike aircraft. It also means killing the Lightning we know.

Based on realistic development timelines, it's still a long way from flying when the 1957 Defence White Paper is published. It was ordered less than six months previously. But the RAF makes a case that the P.1121, as well as being able to serve as the 'last manned fighter' for air defence, would also be essential for defending what remains of the Empire.

The first flight of the prototype takes place in November 1959, powered by an Olympus 21R. An interceptor/air superiority fighter is seen as a priority, but the lengthy development timeline means it doesn't fly until April 1962, and entry into service begins in September that year. This aircraft is probably about equivalent to the Lightning F.3, but may include the automatic intercept system not fitted to that type and probably has drop tanks. It is followed into service by a T.2 conversion trainer, the FGA.3 fighter-bomber in 1965, and the FR.4 fighter-reconnaissance in 1963 or 1964, based on timelines for development of the Mirage III variants. My guess is that the FGA.3 and FR.4 are different enough from the F.1 to warrant a dedicated T.5 trainer.

Production of these types is post-Spotswood, so we probably get something like:
  • 3 prototypes
  • 20 development batch aircraft, of near-production standard
  • 218 F.1 to equip ten squadrons; this is as per Lightning production.
  • 44 T.2, again as per Lightning production.
  • 155 FGA.3 to equip eight 12 UE fighter ground attack squadrons, two each in the UK, Germany, the Middle East, and the Far East. Pleasingly, the same as the number of P.1154 planned.
  • 40 FR.4 to equip two 12 UE fighter reconnaissance squadrons in Germany.
  • 39 T.5, based on the ratio of Lightning fighters to trainers.
That's a total of 495 production aircraft - which isn't too shabby.

At this point, there are enough AI.23 sets produced (at least 373 for the F.1 and FGA.3) that the rumoured CW illuminator from the 200th unit becomes possible. It's therefore reasonable to imagine an F.6 with avionics improvements, including the incorporation of the improved AI.23 and a SARH missile to complement/replace Red Top. Maybe even the more powerful Olympus 22R as well. Given the timelines, this is probably going to be the 1962 proposal to fit Red Top with an R.530 seeker. These aircraft are probably produced by upgrading selected F.1s rather than newbuild.

Export is going to be challenging. This is a lot more aircraft than a Lightning or Mirage III, and I can't see many of the countries that purchased either being particularly keen. A good sales effort in Australia might bear fruit, but I wouldn't hold my breath. A simplified day-only version - effectively an equivalent to the Mirage 5 - might be a little more appealing to some of the Middle Eastern customers that traditionally looked towards the UK for procurement, but it's still a lot of aircraft. Ironically, it might actually push Saudi Arabia and Kuwait to buy F-104s, F-5s or Mirages instead of their Lightnings.

Now, what does all this mean?

The positive is, the UK also has a domestically-developed Mach 2 aircraft capable of most tactical roles. Which is nice.

On the down side, we've killed the Lightning. So the RAF doesn't get a Mach 2 interceptor at all until two years later than OTL. We probably also have killed the Hunter FGA.9 and FR.10 - in that case, the Venom, Meteor and Swift have all been forced to run on for another five years or so, though we're also skipping the P.1154 and going straight from museum pieces to Mach 2. The P.1127 is also going to be stillborn, and that's one of the great successes of the UK aviation industry after 1945. That's a big change, and definitely not a good one. So that's a lot of negative.

Overall, I like the P.1121. I wish it worked for the UK. But the timelines just don't work out, and the opportunity cost is too great.
 
Brilliant ! My gut feeling is: on export markets P.1121 is trapped between F-104 and Phantom... somewhat like the F-105. What makes it big and expensive is the Olympus engine.

Still: don't you think the P.1121 could rob a few Phantom orders here and there ?

Greece
South Korea
Turkey
Australia
Egypt
Germany
Greece
Iran
Israel
Japan
Spain
United Kingdom
 
Export is going to be challenging. This is a lot more aircraft than a Lightning or Mirage III, and I can't see many of the countries that purchased either being particularly keen. A good sales effort in Australia might bear fruit, but I wouldn't hold my breath. A simplified day-only version - effectively an equivalent to the Mirage 5 - might be a little more appealing to some of the Middle Eastern customers that traditionally looked towards the UK for procurement, but it's still a lot of aircraft. Ironically, it might actually push Saudi Arabia and Kuwait to buy F-104s, F-5s or Mirages instead of their Lightnings.
Couldn't the P.1121 be a good alternative to the second-hand Hunters sold everywhere in the end of 60s & 70s ?
Maybe Chile could buy them instead of Hunters in 1967.
Singapore could buy around forty, in 1971.
 
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Working Olympus 21R for a first flight in November 1959 is hard to achieve.

Olympus 21R was Olympus 21 (301) as used in the Vulcan with a new afterburner. Olympus 21 first ran on a test bed in January 1959 and flew on a Vulcan in May 1961. It saw numerous issues with surge margin.

Olympus 22R first ran on a testbed in March 1961, an interim engine flew in a Vulcan testbed in February 1962 and TSR.2 prototype September 1964. It was based on 21R with some improvements.

I'd suggest the 3 prototypes and 20 pre-series aircraft at least must stick to Gyron, possibly even your F.1 production.
 
Couldn't the P.1121 be a good alternative to the second-hand Hunters sold everywhere in the end of 60s & 70s ?
Maybe Chile could buy them instead of Hunters.
Singapore could buy around forty, in 1971.
A country that's buying second-hand subsonic day fighters is unlikely to have the money for new Mach 2 all-weather fighters!

I did make a list of the countries which might be prepared to listen to the sales brief - it's basically the countries which bought Mirage IIIs, but which had a history of operating UK aircraft:
  • Abu Dhabi (26 FGA, 3 FR, 3 trainers)
  • Australia (49 F, 51 FGA, 16 trainers)
  • Belgium (63 FGA, 27 FR, 16 trainers)
  • Chile (29 FGA, 4 FR, 9 trainers)
  • Kuwait (12 FGA, 2 trainers)
  • Lebanon (10 FGA, 2 trainers)
  • Peru (34 FGA, 6 trainers)
  • Saudi Arabia (34 FGA, 6 trainers)
  • Switzerland (37 F, 18 FR, 5 trainers)
The Phantom list isn't particularly informative, IMO, because very few Phantom operators showed much interest in buying aircraft from the UK. It might be more useful to look at F-104 operators; Denmark and Jordan are the ones that jump out at me.

In all cases, I think that the Hawker sales team are going to have their work cut out for them. It's going to be more expensive than an F-104 or Mirage, and less capable than a Phantom. Not an especially compelling offer.
Working Olympus 21R for a first flight in November 1959 is hard to achieve.
Yep, engines are difficult; the Olympus timeline isn't great, and the Gyron doesn't seem to have been as satisfactory as hoped. I think your book refers to the Ol.15R being looked at in the early stages, that could be an option for development flying.

If the F.1 does get the Gyron, I suspect that replacing it with the Ol.22R in the F.6 becomes very likely.
 
And if France refuses to sell Mirages to Brazil because of a possible hoter "Lobster War", perhaps the P.1121 could be an interesting alternative.

Can the price of a possible P.1121 be considered equivalent to that of a Mirage III or F-104 ?
 
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Can the price of a possible P.1121 be considered equivalent to that of a Mirage III or F-104 ?
Almost certainly more expensive, though how much is anybody's guess. It's a bigger aircraft, likely produced in smaller quantities, both of which will tend to increase cost. Avionics are probably broadly comparable between the three, which narrows the gap.

In the best possible case, it steals about half of Mirage III sales, giving them about the same total production. But I don't think that's very likely, given the cost. The F-104 would barely notice the effect.
 
So the two remaining export customers are Kuwait and Saudi Arabia, who find themselves without Lightnings.
Perhaps this would have benefited Kuwait, whose air force had failed to properly maintain its Lightnings and had quickly replaced them with Mirage F1s, after only nine years of service.
With a single engine, would the P.1121 have been easier to maintain ?
 
The smaller P1116 offered a better fighter/bomber solution, indeed an F16 ten years before the F16.
The P.1116 wasn't appreciably smaller, but was more focussed on the 'bomber' part of fighter-bomber. It was probably nearer the F-105 in concept than the P.1121 was, and doesn't particularly resemble the F-16 beyond having a chin inlet. The P.1121 as originally proposed was a response to the P.1116 being too optimised for low-level nuclear strike, at the expense of being a general-purpose fighter.

Later iterations of the P.1121 became twin-seat low-level strike aircraft aimed at OR.339, but that was very much not the original design intent.
With a single engine, would the P.1121 have been easier to maintain ?
It probably would have been; it's actually comparable in size to the Lightning, so might actually come out cheaper to both buy and to operate. Not that the Lightning lost many export opportunities on price, as far as I'm aware.
 
Hmmm...I thought I'd gone into this scenario a while back.....

Anyway let's begin.
Let's start with some real dates.
And promptly avoids the origin of P.1103 (March 1954) and it's submission to F.155 (March 1956) and the advice given to Camm by Sir Thomas Pike (3 May 1956) to look into a more small wars development of such.
Which began 8 May leading to P.1116 which was subject to quite some criticism (essentially it's not F.155 material) and a second submission was developed launched 28 May designated P.1121.
Which was submitted 12 June.
The projection was order first for
1 August '56
prototype December '58
First delivery June '61

RAF stated 2 October '56 that the future was P.1B possibly Saro F.177 until '64/'65 when a new Fighter to OR.329 was expected. So this is controversial and would hit some resistance.

In a scenario where something like this is ordered we have to ask the obvious question. When?

Ordering to F.155 would be controversial but dates to 27 March '56 as P.1103.
Ordering August means accepting Hawkers schedule and any delays be down to Hawkers.
Prototype might slip into '59.
And delivery might delay to '62.

The missile radar combination is then currently tied to Lightning and doesn't exert obvious delay.
The engine was still Gyron, which might well exert delays.

Ordering by Sandys would be 29 March '57 so a minimum of 7 month delay.
Ordering before 25 September '57 avoids the moment when the Company Board slows the rate of expenditure.
April '58 is when work stops with the machine half completed, so arguably this is the last sensible moment to order this forward.
By which point the schedule has obviously slipped by nearly two years. Implying delivery in '64/'65.

Brochures were prepared in 1959 for export.
 
And promptly avoids the origin of P.1103 (March 1954) and it's submission to F.155 (March 1956) and the advice given to Camm by Sir Thomas Pike (3 May 1956) to look into a more small wars development of such.
We could go the P.1103 route, but even then you'd be starting from the selection date, which was the Tender Design COnference on 27 March 1956. That gives about a six month head start on my timeline, which (I suspect) doesn't materially change anything. Given that P.1121 did start as a general-purpose fighter derivative of P.1103, it's perfectly possible for the FGA and FR versions to come along in the fullness of time.
RAF stated 2 October '56 that the future was P.1B possibly Saro F.177 until '64/'65 when a new Fighter to OR.329 was expected. So this is controversial and would hit some resistance.
This is where we hit the issue. We need the RAF to ditch P.1B and F.177D in March 1957 in favour of the Hawker fighter, because they're only getting one. Whichever date you pick for the formal start of the project, you're racing the clock - and given that F.177D didn't beat it, you really need to start in 1954. Which, of course, P.1B - and not a lot else - did.
 
you really need to start in 1954.
To be fair, I think this is correct.
Outside of Type 545 Crescent Winged Swift, P.1B Lightning, Scimitar, DH110 Sea Vixen, Javelin and N/A.39 Buccaneer everything looks too late.

Arguably F.177 makes a better alternative to Hunter and outperforms Lightning in pure interception.

So in timing only an alternative to Lightning....which would be AW.58 or Fairey Delta II, and an alternative to Buccaneer, which would be Shorts PD.13. Meet the timing criteria.

Getting the off of pure interceptors and opting for Small Wars Aircraft raises it's own questions.
But of the option P.1103 can meet certain criteria.
Such as radar guided missiles for Fighter operation.
And two seats for Ground Attack.
Single engine likely does make this more affordable than Lightning.

And if we believe the schedule, it's achievable before 1965.
 
Arguably F.177 makes a better alternative to Hunter and outperforms Lightning in pure interception.
F.177 is generally more promising, IMO. Timelines are better than P.1121, it's more adaptable to the ground attack role than P.1B, the Germans might have bought it, and the Navy wanted it too.

There is the small issue of the rocket being a better idea in theory than in practice, but that will come out in the wash.
 
We need the RAF to ditch P.1B and F.177D in March 1957 in favour of the Hawker fighter, because they're only getting one. Whichever date you pick for the formal start of the project, you're racing the clock - and given that F.177D didn't beat it, you really need to start in 1954.

This 1957 timeline works for me.

For comparison’s sake, here’s the similar Mirage III timeline… the key might be for Hawker to start some internal development work before a government order in 1957 (which I assume they were doing).

Company funded demonstrator: 1956 - mid-1957
March 1956: Mirage III 01 blueprints completed; prototyping starts
Nov 1956: 1st flight Mirage III 01

Prototypes/Development: Mid-1957 - End 1960
June 1957: Mirage III A ordered (10 prototypes / pre-production aircraft)
May 1958: 1st flight (A-01)
Feb 1959 - Dec 1959: Aircraft A02-A09 delivered

Initial Production: Mid 1958 - 1962
Aug 1958: Mirage III C ordered (100 aircraft)
Oct 1960: 1st flight of production-standard IIIC
1961: 37 Mirage IIIC delivered
1962: 58 Mirage IIIC delivered (total 100 built by 31 Dec 1962) ; production rate reaches 9x/mo
 
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Correct P1121 was more like the F105, which didn’t have that much overseas appeal.
Too focused on low level nuclear attack, very little air-to-air capability beyond the 20mm gun. It really needed to be able to carry a couple of Sparrows and/or Sidewinders in addition to the regular bombload. Basically, it needed to be an F-4 a generation earlier.


With a single engine, would the P.1121 have been easier to maintain ?
Loosely speaking, yes. One engine means roughly half the maintenance hours compared to Lightning's engines, but you'd still have a radar and missile system similar to Lightning (if not the exact same system!) that takes up the same amount of maintenance.

Exact breakdown depends on how much maintenance each "area" requires: Engine, airframe, combat systems. At a rough guess, you'd save about 25% of the total maintenance hours.


F.177 is generally more promising, IMO. Timelines are better than P.1121, it's more adaptable to the ground attack role than P.1B, the Germans might have bought it, and the Navy wanted it too.

There is the small issue of the rocket being a better idea in theory than in practice, but that will come out in the wash.
As soon as people figure out afterburners, I would bet that the rocket engine and oxidizer tanks would come out, probably replaced with more fuel tanks.
 
Not happening. Greece more or less followed an unofficial policy of not buying major British systems between 1955 and the early 2000s. Besides what advantage is P.1121 supposed to offer over F-4E the first fighter actually bought after WW2? F-104 and F-5 do not count they were given for free by the US.
South Korea
Turkey
Neither has bought any non American fighter jet since... well the creation of the jet.
Is politically motivated to want F-4E post Camp David, won't be able to buy prior to Camp David...
Britain won't sell just like with Chieftain.
 
1121 would have been the British Thunderchief. A useful strike aircraft which would have fit between Hunter/1154 and Canberra/TSR2. Not sure whether it would have tempted the RAF away from Lightning then Phantom.

1121 was a beautiful airframe but like all British designs weak on armament and avionics. Changing those requires a great leap.
 
As soon as people figure out afterburners, I would bet that the rocket engine and oxidizer tanks would come out, probably replaced with more fuel tanks.
The rocket was, in theory, very useful for high-level work, to an extent that reheat isn't, because it doesn't depend on getting combustion air in. Which is why the F.155 and F.177 interceptors both used them - they were meant to go after Soviet supersonic bombers at altitudes up to 60,000 feet. Since that threat didn't really materialise, the rockets wouldn't have been much use.

Worth noting that the Mirage III also had provision for a rocket. It was very rarely fitted.
 
Difference was that the Mirage III rocket was a removable pack. Could fly high and at Mach 2 without it. Unlike Saunder Roe design. The real french equivalent was the SO-9000 Trident.


To be honest main problem with those rockets relates to the oxidizer. There are too few options, all of them flawed.
-N2O4 is a corrosive bastard
-LOX is deep cryogen
-H2O2 / HTP is unstable, explosive stuff
-N2O is mild cryogen and can detonate too (Virgin 2007 incident)
 
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I was "playing" with an AI generator when I enter this prompt : "A fighter plane in the style of the 1960s, flying over the sea, with clouds"
Did you specify the nationality at all? Did you have Hawker-related tabs open?

It looks like a mid-stage Pokemon halfway between basic (Hunter) and final (P.1121) forms.
 
Meh, A.I biased toward British designs. Maybe it is because it swallowed all those @uk 75 threads, plus all the wonderful Tony Buttler books ? (half joking obviously !!!)
Don't forget, machine-learning is basically a giant sponge and savant idiot, sucking Internet like a black hole. (to the point that some A.I results looks like porn - how surprising. Remember what Lenny told Homer Simpson about his website ranking first after porn, that is: 2 million. Simpsons being prescient: as usual.)
 
I have tried now and again to do alt history threads about non-British stuff like the German attempts to replace the Fiat G91 but perhaps because Britain is the home of Fred in a Shed its the Brit stuff that starts a pub bore, brawl or good night out depending on your view.
View: https://youtu.be/xWenMqtesyM?si=ZuwakdsXHXjAgJyp
 
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It's true that AI has a marked tendency to produce aircraft in British colors.
Well, at least in the experiments I did.
 
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