Design Exercise: A British F-4 Phantom-like aircraft

[zen]

Components wise, much of what is needed was or nearly was available to achieve a nearly sort of British F4 Phantom II.
But historically this never came about and that of course makes for some entertaining AH scenarios.

But perhaps it might entertain some to theorise what such a design might be and what would or would not be included.

The most obvious component is the near ubiquitous Avon turbojet in one of it's many variants.

In terms of radar the AI.18 is the centerpiece of 1950s efforts, and we know it was tested with limited doppler circuits for look down capability.
Though by the late 50's early 60’s AI.23 could potentially achieve multifunction leveraging off Lightning and Buccaneer variants.

 

[Archibald]

I said it in the other thread: on paper at least, Great Britain had all the elements on hands to get a world-beater

- RB153 / Adour / M45 / RB172 "compact turbofan"
- top notch avionics, from the Lightning F6 and the Buccanneer (there is peculiar bit of advanced electronics I never remember the name, TLIAD ? )
- Blue Dolphin & Red Top AAMs (think Magic & 530 families, AIM-9 / AIM-7)

It is essentially a matter to blend smoothly
- the F-4K (US old design not adapted to the Speys)
- the Jaguar (attack bird, compromised, underpowered)
- the Tornado (top notch for attack, but underpowered with heavy VG for air combat... the ADV did an honorable job but was no F-15 by any mean)

I would love to model such an aircraft in 1/72 with bits of Jaguar, Tornado and Phantom.

For example: a 1/48 scale Jaguar (otherwise it is too small) with 1/72 scale Phantom wings and 1/72 scale Tornado intakes, fin and tail.

 

[Archibald]

I would say - start from the Phantom and try correcting its four main flaws

a) it is a US design
b) from the 50's
c) with "old" turbojets (J79)
d) it lacks manoeuverability

- With a pair of RB153 / RB172 the new aircraft could be notably smaller (perhaps by 20%) while having much better fuel economy.

- it was possible to get a LWF, agile fighter long before the F-16 / F-18 / F-20: it was called... the F-5 Tiger !

You know what ? a scaled-up, British F-5 with a pair of RB153
(hello, P530 Cobra !)

Just to screw the F-5 (and attack the Phantom from "below") unlike the F-5
- put a decent radar, medium-range AAM (Blue Dolphin DAMN IT) and mach 2 top speed.

Such bird would be a Hornet look-alike... a decade before the Hornet.

It would also bury the Mirage III and even the F1 would have difficulty catching up.

Note that a lot of countries bought Mirages III & F1 rather than F-5s because, just like the Phantom: they had a decent radar and a medium-range AAM, the R530.
The Mirage(s) filed a niche between the F-5 and F-4, really. And it is hardly surprising the (unfortunate) Mirage 2000 had not one, but THREE F-5 successors to fight: the F-16 and the F-18 and the F-20.

 

[Archibald]

Whatif we used a 1/48 scale F-5E Tiger to represent that bird in 1/72 scale ?

Wikipedia tells me that a F-5E is 14.7 m long, span 8.13 m and 4.1 m tall.

Quite logically, going from 1/48 to 1/72 (or reverse) is 1/3rd larger or smaller. Or maybe I'm completely wrong: I'm loosy at fractions and percentages.

Whatever... a 33% larger F-5E (we suppose it swallowed steroids like Lance Armstrong and inflated accordingly...)

14.7+(14.7/3) = 19.6 m long
8.13+(8.13/3) = 10.84 span
4.1+(4.1/3) = 5.47 tall

Same length and height as a F-15 but much shorter span. Whatever.

Put RB153 into that bird, plus medium range AAM, AI23 and mach 2 speed, and tadaaam, a British Hornet long before the Hornet.

 

[red admiral]

Twin Avon = Supermarine 556 or Hawker 1125/1129?

Probably envisage 556 as the starting point and then a notional MK2 follow on with better area ruling and revised multi-shock intakes for Mach 2?

Still missing a dogfight IR missile

 

[zen]

So on a theoretical side what options could have been developed?
Wings:-
Straight
Swept
Crescent (HP and Supermarine)
Delta (Avro)
Ogive (Bristol)
Aero-Isoclinic (Shorts favoured this)

Do we mount the wing high, middle or low?
Low makes for short undercarriage and less weight, but not so easy for pylon weapons carriage.
High is better but forces the undercarriage into the fusilage or it gets long, stalky and heavy.

We have options for:-
T-tailplane
Mid-tailplane
Low Tailplane
Canard
Tailless

For volume the Delta wins.
For progressive and benign stall characteristics the Crescent wing.
Shorts made quite some claims for the benefits of their aero-isoclinic wing, high rates of roll and less weight than having a tail.

The Canard gave good lift and helped at altitude, but there were issues....stability I seem to recall.

The low tail was a good solution, but the RAE didn't like it until the results were rammed into their faces after expensive trials.

 

[overscan (PaulMM)]

What the point of making a new thread for this?

https://www.secretprojects.co.uk/threads/getting-a-british-phantom.37094/

 

[zen]

What the point of making a new thread for this?

https://www.secretprojects.co.uk/threads/getting-a-british-phantom.37094/

Well this is theory, not AH as such.
More a ramble through design concepts, rather than politics or actual designs of the era.
What could have been done rather than what was....even on paper.

Too often this gets bogged down in company X or Y, design A or B and how it doesn't mesh over in AH.
So I thought why not explore what ought to have been done?

 

[_Del_]

- the F-4K (US old design not adapted to the Speys)
- the Jaguar (attack bird, compromised, underpowered)
- the Tornado (top notch for attack, but underpowered with heavy VG for air combat... the ADV did an honorable job but was no F-15 by any mean)

This will delve closer to AH, but I've often wondered what might have resulted if the original MOU for a light-strike/trainer and the bigger, more capable AFVG, had stayed closer to it's roots.

No resulting Jaguar, but an earlier joint-Hawk/Alpha Jet. Then something aimed at the sweetspot between the Jaguar and the larger, more ambitious AFVG designs.

 

[overscan (PaulMM)]

AI18 is a dead end. AI23 developments is what you should be looking at. It had monopulse tracking and was a much more adaptable design.

As I was told by a knowledgeable person in the late 80s - Ferranti always delivered. Marconi... didn't.

In terms of a Phantom equalling design, technically Olympus is the right technology level not Avon, which is running out of potential in late 1950s. This really means a single engine fighter to be in the right size bracket. Then delta wings are tempting, which leads to a scaled up Mirage III with more thrust, more efficient engines and better radar. Or perhaps double delta like Draken. More costly than either though.

Missiles are less obvious. Sidewinder was much, much cheaper than Red Top. Red Top was technically superior but more complex with lots to go wrong so needed more babysitting.

Adapting AI23 with a CW transmitter for Sparrow was only an issue due to limited space in the Lightning nosecone. So that makes sense, replaced by Skyflash when possible. Adopt Sidewinder but replace seeker with Red Top derived one - the same methodology as Skyflash.

 

[zen]

Well certainly since AI.23 was funded for Lightning and Buccaneer, the merger of functionality together seems just a matter of increased volume, weight and cockpit controls.
All available by the early 60’s.

The volume question might be answered by the supersonic Buccaneer variant which was offered to Canada. This had a much longer nose, presumably to house the electronics for that.

As for engines, obviously had RB.106 or BE.30 funded would deliver the sort of powerplant for a twin engined fighter.

However the design is not so clear.

Sorely tempted by Shorts Aero-Isoclinic wing or the Crescent wing. Both offer better stall characteristics, which are vital for carrier aircraft.

 

[Pioneer]

I would say - start from the Phantom and try correcting its four main flaws

a) it is a US design
b) from the 50's
c) with "old" turbojets (J79)
d) it lacks manoeuverability

And may I please add:

e/ lack of built in cannon armament

Regards
Pioneer

 

[royabulgaf]

The Supermarine 556 was a side by side version of the Scimitar. I can't imagine that improving performance. Engine upgrades and better weapons systems aren't going to turn it into a Phantom. You really need a clean sheet of paper. Broadly, it was to fulfill the role of the F4U in WWII. A fleet defence interceptor that could also function as a bomb truck. For whatever reason, the Phantom caught lightning in a bottle. Some riff on the Buccaneer, or Scimitar, or Sea Vixen will only catch lightning bugs.

 

[H_K]

Would a single-engine, two-seater Spey 203 powered design work?

Ideally I would want a sleek, modern Mirage F2/F3 style design (indeed the Spey was the backup engine when offered to Israel in 1965)... but for carrier compatibility and keeping in mind the technology available for an earlier introduction in the early/mid-60s I’m kind of intrigued by the thought of an upscaled Etendard style design. (I know, I know...)

Or along the same lines but maybe less controversial, an upscaled Super Tiger style design.

With a fuel efficient Spey, either option would make for a balanced interceptor/strike design, assuming 4-4.5T internal fuel and 8-9T empty weight.

 

[zen]

I have mused on the concept of a larger twin engined Etendard type design in other threads and it does seem plausible.

 

[zen]

Royalbugaf
This is a theory thread on what could or ought to have been designed.
Not a thread on AH as such and not a thread of a specific extent design.
Go over to the AH section and browse. There is plenty.

 

[zen]

More on this.

Radar approximately the right time and the spectrum of options.

Hughes/EMI Pulse-Doppler radar for P.1154 (800lb weight)
Designate this H/EMI-PDR

Ferranti OSIRIS Pulse-Doppler radar for the P.1154
Designate this OSIRIS-PDR

Elliott coherent radar proposal for Lightning
Designate E-CR

GEC incoherent MTI module for AI Mk 18 adaptable to AI Mk 23
Designate GEC-AI.23-MTI

Ferranti / Hughes coherent MTI module for AI Mk 23 (based on CORDS for the AN/APQ-109)
Designate F/H-AI.23-CORDS

 

[Pioneer]

I would say - start from the Phantom and try correcting its four main flaws

a) it is a US design
b) from the 50's
c) with "old" turbojets (J79)
d) it lacks manoeuverability

- With a pair of RB153 / RB172 the new aircraft could be notably smaller (perhaps by 20%) while having much better fuel economy.

- it was possible to get a LWF, agile fighter long before the F-16 / F-18 / F-20: it was called... the F-5 Tiger !

You know what ? a scaled-up, British F-5 with a pair of RB153
(hello, P530 Cobra !)

Just to screw the F-5 (and attack the Phantom from "below") unlike the F-5
- put a decent radar, medium-range AAM (Blue Dolphin DAMN IT) and mach 2 top speed.

Such bird would be a Hornet look-alike... a decade before the Hornet.

It would also bury the Mirage III and even the F1 would have difficulty catching up.

Note that a lot of countries bought Mirages III & F1 rather than F-5s because, just like the Phantom: they had a decent radar and a medium-range AAM, the R530.
The Mirage(s) filed a niche between the F-5 and F-4, really. And it is hardly surprising the (unfortunate) Mirage 2000 had not one, but THREE F-5 successors to fight: the F-16 and the F-18 and the F-20.

I've seen reference to the Mirage F1 'being an austere F-4 Phantom II'.
And that said, I guess it is/was....


Regards
Pioneer

 

[zen]

Hmmm a Mirage F4 is something I hypothesise.
A F2-like or F3-like twin engined multirole aircraft.

Sadly the only things I've seen like that are actually larger French Strike designs.

 

[Archibald]

Hmmm a Mirage F4 is something I hypothesise.
A F2-like or F3-like twin engined multirole aircraft.

Sadly the only things I've seen like that are actually larger French Strike designs.

Yup. The G4, G8 and ACF more or less covered all twin jet large types.

Now, an AFVG without VG but keeping the small and light RB.172 / M45...

 

[uk 75]

The problem for the UK is having to replace a slew of different fighter/bombers at the same time

Hunter in Ground Attack/ Recce by 1968
Javelin in All weather interceptor by 1967
Scimitar in fighter/naval strike by 1965
Sea Vixen in all weather naval interceptor by 1968
Low end of Canberra light bomber/recce by 1968

The naval 1154 in two and single seater versions with twin Speys and a bigger wing
plus Buccaneers seems to me the best design.
A swing wing BAC583 without the vertical lift stuff might also work.

 

[zen]

584 had the lift jets for STOL.
583 had just a VG wing

 

[uk 75]

I was thinking of the smaller BAC583V.

 

[zen]

I was thinking of the smaller BAC583V.

That's a nuts design, VG wings and four poster BS.100 with PCB.

At least choose something sensible, like the fixed wing P.45 or P.141.
Frankly ship out the VTOL kit from P.1152 is better.

 

[uk 75]

The.V with sensible engines and swing wings.is small enough, smaller than 1154, 583 and 141, to operate from RN small carriers as well as be able to use side roads and taxiways at damaged airfields.
The P45 with fixed swept wings is pretty close to Jaguar.

We always get back to single engine designs.. Apart from trainers the RAF will not accept a single engine fast jet after the P1127/1154.

A smaller Phantom is pretty much Jaguar then Tornado to Typhoon.

Could we have designed a better aircraft than Jaguar? Probably but it would never have got built.

 

[zen]

Sensible engines.....

BS.100
Pegasus
RB.153, M.45, RB.172, BS.94

Because to get the Speys is to sacrifice it's supersonic components to keep the weight down.and that impacts the very reason you'd want them.

As for a VG wing as well. Complexity, increased maintenance burden, major design headaches when coupled with the four poster vectoring nozzles and the vexing question of where the main gear goes.
Sounds like enormous cost compared to P1154, and P1154 is expensive compared to P.141.

P.45 is like Jaguar on steroids with nitro injection. Twin RB.172 of 13,000lb reheated each.
Equivalent to four Adours power but the weight of three.

 

[uk 75]

P45 or the P62 fixed wing version posted in the P45 thread seem to be the only sensible design proposed in the 60s. The others all have various major flaws pointed out in threads.
A fixed wing P45 would have had to be developed by 1962 with prototype flying in 64/5 and in service around 1968 with RAF and possibly RN.
It would have replaced Hunters and Sea Vixens. Lightnings replaced the Javelins.
An evolved larger P45 similar to UKVG would have replaced Buccaneers/Vulcans and Lightnings in the 70s
This would have given the RAF two fast jet families by 1977.
The cost of these programmes would have been much less than P1154, TSR2, Phantom, Jaguar and MRCA/Tornado.

 

[zen]

Being far from my books buried in storage. I cannot confirm such a date.
But certainly it would have made sense to have comparison variants of Types 583 and 584 without VG wings.
Vaguely I recall the Folland Fo.147 with twin RB.153s, a variant with a fixed wing returning to it's Gnat mkV roots. Would be quite attractive.

In fact Brough's OR.346 offering included a smaller single Medway powered version applicable for carriers. With reduced range (less than 1,000nm RoA and 4 hour CAP)
Sadly DH didn't do the same with their offering. As had they done so...

But this takes us to another point.
It would ultimately be cheaper to run off variants of a design for different missions. Rather than trying to modularise the avionics into swappable units or cram the lot into a multirole Wonderweapon.
I suspect this is the Achilles Heel of the likes of Type 583 and 584, and P1154. Much as it was for the TSR.2.

What P.45 and the Fo.147 showed was a bare bones set of interceptor equipment could deliver a cheaper to run Lightning successor.
Similarly with Attack equipment. As ultimately the Jaguar proved.

And this I suspect this is behind Brough's P.141 concept.
Similar to the Swedes who built specialist variants of the System 37 Viggen.

Even the mighty F4 if anything suffered from this habit of cramming the lot in. Offset in part by size.And power of the engines.

But if you want small, light, cheap. Then the F4 scale solution isn't the answer.

P.45, or Fo.147, could have been sort of proto-hornets, albeit back before avionics merged Attack and Fighter capabilities.

 

[uk 75]

The main problem with comparing any paper designs with those actually built (TSR2) or nearly built(1154) is that the RAF and RN are awful customers. They want Cordon Bleu steak for the price of a Big Mac.
When the politicians force them they end up with right aircraft but only after trying the wrong ones. So Buccaneer proves to be the Canberra replacement and Jaguar the Hunter replacement.
It does not always work. Tornado should have had the range of AFVG and UKVG. This would have allowed it to be based in UK rather than RAFG and reach targets like Murmansk.
The UK only gets stuck with the Phantom because of the Royal Navy. By insisting on the overblown P1154RN or F4 rather than some of the other alternatives we have mentioned here the RN gets into the position of having carriers (Hermes) and no fighter able to operate from them. Ark's F4s were a too tight fit.
The Lightning was fine for coping with Bears and Badgers. When Fencers and Backfires come into widescale service an AFVG/UKVG or P45 derivative with modern missiles is needed after 1975.

 

[zen]

Anyway back to the topic.

Wings:-

1) Straight
2) Swept
3) Aero-Isoclinic
4-1) Crescent or (4-2) compound leading edge sweep
5) Delta
5-1)Double delta/cranked arrow

Tailless
Tailed
Canard

So of these to achieve F4 like performance but be navalisable for the RN. One would really need to utilise lift improvements for low speeds.
These come down to :-

a) Blow over the wing and tail
b) Lift jets
c)Transforming features:-
c1) variable incidence wing
c2) variable geometry (sweep) wing
c3) flip out extra lift surfaces

 

[Archibald]

The main problem with comparing any paper designs with those actually built (TSR2) or nearly built(1154) is that the RAF and RN are awful customers. They want Cordon Bleu steak for the price of a Big Mac.

Cordon bleu (cuisine) — Wikipédia

fr.wikipedia.org

Those disgusting things are actually as cheap as a Big Mac.

Wait...

You mean cordon bleu chief, as in "la grande cuisine" ? Indeed this kind of cordon bleu is far more expensive that old Ronnie McDo "food"...

 

[zen]

I think it's haute cuisine.

Though we might say Champagne taste but beer pockets

 

[zen]

Low wing
Mid wing
High wing
?

Low results in shorter main gear = lighter weight, but costs in wing volume and complexity in structure.
A finely balanced design like the F4 is highly shaped for a specific engine.
The shorter Spey caused issues just because of this not resting on the main spar carry through.

High wing results in either fusilage main gear and volume issues (but simpler wing) or long stalky main gear and weight increased.

Mid wing has structure issues often resulting in 'o' rings for engines. Again making engine changes difficult.

However podding the main gear Tuplavov style can help at the cost of increased cross sectional area.

 

[uk 75]

France is much less dogmatic than the UK about requirements.
Thus it lives with a modest number of R530s on the Mirage and settles on the F8 Crusader as the sensible fighter for an Essex size carrier like Foch/Clemenceau.
It is only because the French choose it as a Light Strike aircraft that the RAF gets Jaguar at all. Just like the RN Buccaneers once the RAF gets Jaguars (ok modified somewhat) it likes them.
The UK wants a two engined two seater aircraft capable of carrying 4 radar and 4 heat seeking AAMs with a suitable radar to replace Sea Vixens, Javelins and eventually Lightnings.
P45 is the best starting point for this as in real life.
Any single engine F5/F16 type can only serve in a "fantasy" RAF.

 

[red admiral]

P.1154 two seat RN version with twin Speys

• No vectoring nozzles, extended rear fuselage/nozzles
• Single wheel main undercarriage retract into fuselage sides where forward vectoring nozzles would otherwise be
• Larger area wing/tail with blowing. Maybe crescent wing, or a strake as per Blue Envoy
• 4 hardpoints under fuselage for radar AAMs
• 3 hardpoints per wing, inboard fuel tanks, outer IR AAMs

 

[zen]

I think in the 1950s it would not be the future P1154.
And a CTOL version of P1154 is still so compromised, that it would be better to start afresh. Which is exactly what did happen.

Essentially the best case here was a Brough parallel STOL study as back-up to P1154 in event it proved a failure. Just as they did later for P1127 with P.146
And frankly the earlier P.141 NGTA with modular nose and cockpit options for different roles is the right approach.
But that is all 60's stuff.

For a UK parallel to the F4, we are talking the 50's.

However this is again pulling the thread into AH not theory.

Theory is we look at what was possible at the time and effectively imagine another aviation company pulling a F4-like solution out of it's hat. J. Blogs Aviation let's call it.

 

[red admiral]

It feels pretty difficult to get an equivalent aircraft given how much heavier and draggier Red Top and derivatives are compared to Sparrow and Sidewinder.

 

[uk 75]

Assuming a fantasy aircraft for the late 50s you are simply finding an excuse to dredge up weird British missile designs derived from Firesteak, which as red admiral suggests are much heavier and draggier than US equivalents.
I suggest you have a word with the Whatifmodelers crowd or Beyond the Sprues who love this sort of thing.

 

[zen]

Assuming the development of RB.106 engines.
Reheat Chambre diameter is approx 42 inches. Assiming a 1.5 inch structure to exterior skin then exterior diameter of 45 inches. This represents the absolute minimum basis for Cross Sectional Area.
So 11.045 Square feet of area to cover two hemispheres and then 14.063 Square Feet for a Square between the two hemispheres. Just enough area for the engines only is thus 25.107 square feet.

A third hemisphere could encompass cockpit, very tight undercarriage storage and other components. Total would thus be 30.63 Square Feet without including the wing.
This of course also doesn't deal with Area Ruling.

However an F4-like study for comparison using similar sized engines (Speys) gives us a figure of 44.5 Square Feet. Raising the question does a wing increase CSA this much or is this indicative of real requirements to house main gear and engines....?

 

[uk 75]

Leaving aside all the alt history stuff I am still puzzled by this exercise.
While you may be taking bits and pieces to design a late 1950s alternative to the F4 you are starting from the experience of 2021.
By putting together some engines, systems, weapons and an airframe you are simply drawing your favourite type of plane outside of any valid context.