UK-Japan-Italy Global Combat Air Programme (GCAP) News & Technical Analysis

[timmymagic]

Japan will have its Japanese versions, such as Engine Japanese and AESA Japanese, etc. when they will build and fly?

I'm not sure what Italian demonstrator? Maybe use British and Japanese to test their Plane? As I can't see any info about this.

There is only 1 demonstrator. Its the UK one.

Obviously there is the UK avionics testbed, Excalibur, as well. I'm unaware of any Japanese or Italian development aircraft of any kind at present in relation to GCAP. I suspect there might be some other Excalibur style testbeds, but probably not on the same scale. Wouldn't be a surprise if the X-2 was used in a support role, but if it is it would be minor in comparison to the BAE Demonstrator.

 

[Kota]

There is only 1 demonstrator. Its the UK one.

Obviously there is the UK avionics testbed, Excalibur, as well. I'm unaware of any Japanese or Italian development aircraft of any kind at present in relation to GCAP. I suspect there might be some other Excalibur style testbeds, but probably not on the same scale. Wouldn't be a surprise if the X-2 was used in a support role, but if it is it would be minor in comparison to the BAE Demonstrator.

There is the C-2 FTB which is scheduled for testing next year and also Japan did some radar and avionics testing using an F-2 as a base aircraft. A lot of what Japan has been doing though has been chamber testing of various equipment rather than flight testing. I don't know that the X-2 was seen on an RCS test rig last year too likely to do with GCAP.

 

[mokahete]

I'd say Kaan is significantly above the KF-21 in terms of capability intent - internal bays are a game-changer is terms of radar stealth, and those won't arrive on the Boramae till later versions, whilst being standard on the Kaan.

The current demonstrator for kaan that flew, does not have internal weapons bay.
And there were total of 2 flights only of current demonstrator, both were short low altitude, slow flight, without any maneuvers, after those two flights its shelved.
The current demonstrator of kaan is nothing as but flight capable airframe.
It didn't flew to normal altitude where fighter jets fly( 40-50k), forget supersonic it didn't even achieve mid level subsonic speeds.
And its shelved now, means this demonstrator will not fly again, so largely confirms its not capable of flight in the same sense a fighter jet is.
It can't even beyond called a flight demonstrator, at most static/ground model that was made to fly for political reasons.

But, Prototypes of kf-21 did all that, also did supersonic flight, weapons firing, they are full fledged Prototypes.


While's ambitions of kaan project is higher than kf21, but in terms of actual progress kf-21 is a decade ahead.

And if korean go for stealthy bk3 varient, that IMO it will enter service before kaan will or if kaan ever will.

 

[mokahete]

and was able to siphon off much knowledge from the JSF programme into the parallel-running Kaan programme during their participation.

What knowledge specifically?

 

[Ron5]

How much is likely to change from this demonstrator to the final production models? Others have said it'll grow in size significantly.

It's important to remember there are two development streams: one ends with a flying demonstrator, the other leads to GCAP/Tempest.

One will not "grow" out of the other.

 

[H_K]

It's important to remember there are two development streams: one ends with a flying demonstrator, the other leads to GCAP/Tempest.

One will not "grow" out of the other.

100%. This is basically EAP circa 1985, not Eurofighter (which started development in 1988, 1st flight in 1994, 1st production aircraft in 2002/2003, IOC in 2004/2005... food for thought for those who believe a 2035 service entry date is possible!).

This is a concept demonstrator or experimental aircraft - basically a skills building program for BAE and the UK, much like Shinshin was for Mitsubishi and Japan (though this is much more advanced). Some lessons will be learnt and applied to GCAP, but it's not the same aircraft nor the same development teams. So all this speculation about size/shape etc is probably somewhat irrelevant in terms of what GCAP will be.

As a side note, I'm very interested to see if FCAS/NGF adopts the same "EAP" approach with their demonstrator, which is running 2 years behind. I have a hunch (based on the money invested in each phase) that they are actually building a proper "Y" series prototype demonstrator, rather than an "X" series experimental aircraft (think YF-22/YF-23 or Rafale A vs EAP), so they may be taking more time but will have a more finished product. Time will tell...

 

[paralay]

Can the size be estimated based off of these two photos?

Yes, and this was published here earlier, approximately so.
We see the cockpit of the prototype here, and it is comparable in size to the Eurofighter, which is significantly smaller than the future fighter jet.

 

[helmutkohl]

Yes, and this was published here earlier, approximately so.
We see the cockpit of the prototype here, and it is comparable in size to the Eurofighter, which is significantly smaller than the future fighter jet.

the top picture looks like it is using the old Tempest mock up from six years ago.
the fuselage parts in the picture is likely reflecting the plane shown in yesterday's picture.

 

[zen]

This is basically EAP circa 1985, not Eurofighter (which started development in 1988, 1st flight in 1994, 1st production aircraft in 2002/2003, IOC in 2004/2005... food for thought for those who believe a 2035 service entry date is possible!).

And the end of the Cold War, massive cuts in defence had no effect on that schedule at all......

Because we couldn't imagine Typhoon being developed to meet an earlier IOC had the threat remained at Cold War levels.....

 

[Nx4eu]

Yes, and this was published here earlier, approximately so.
We see the cockpit of the prototype here, and it is comparable in size to the Eurofighter, which is significantly smaller than the future fighter jet.

For an aircraft/demonstrator that's 20.4m long. Powering it with 2x EJ200's seems a bit inadequate.

 

[H_K]

And the end of the Cold War, massive cuts in defence had no effect on that schedule at all......

Because we couldn't imagine Typhoon being developed to meet an earlier IOC had the threat remained at Cold War levels.....

Well for sure it should be possible to go faster than Eurofighter, but even back in the midst of the Cold War (1988) the RAF was estimating 10 years from start of development to IOC.

And 10 years might be a little optimistic today given what we know about development challenges in complex programs with multiple partners, not to mention software development is a greater challenge than ever before… see F-35 (which took 15+ years to IOC).

 

[Sintra]

As a side note, I'm very interested to see if FCAS/NGF adopts the same "EAP" approach with their demonstrator, which is running 2 years behind. I have a hunch (based on the money invested in each phase) that they are actually building a proper "Y" series prototype demonstrator, rather than an "X" series experimental aircraft (think YF-22/YF-23 or Rafale A vs EAP), so they may be taking more time but will have a more finished product. Time will tell...

Unless Dassault does a "1986", calls P&W or GE and order a couple of engines for the "Y series demonstrator" (something entirely possible by the way) they are going to build a demonstrator (M88 dimensions and all that).
But, yeah, we are going to see an awful lot of "brand new European death and destruction heavy metal flying bits of kit" in the next few years! Glorious times.

 

[kqcke for you]

For an aircraft/demonstrator that's 20.4m long. Powering it with 2x EJ200's seems a bit inadequate.

I may missed something but my understanding was that the actual plane is around ~3-4m longer than eurofighter so the actual demonstrator which we know is only 2/3 of its weight so it hardly can be 20m long.

 

[red admiral]

so the actual demonstrator which we know is only 2/3 of its weight

I think you misunderstood the quote. 2/3rds of the parts by weight have been released to manufacture and are currently being built/already built. It's just a measure of progress in between Critical Design Review and First Flight. There's no comparison in this with GCAP.

 

[H_K]

Unless Dassault does a "1986", calls P&W or GE and order a couple of engines for the "Y series demonstrator" (something entirely possible by the way) they are going to build a demonstrator (M88 dimensions and all that).

Using off-the-shelf engines for demonstrators shouldn't be a huge limitation, whether it's EJ200 for the UK demo or M88 for FCAS demo. Given no weapons load, partial fuel, and potentially a small thrust boost via FADEC tweaks... even if the demonstrator is quite large (say 90% scale vs. the final design, perhaps 14-16t empty) there will be enough thrust to be useful.

Also look at YF-22 which flew with undersized YF-119s... not a problem.

The big difference between the UK and FCAS demonstrators is that I expect the FCAS demonstrator to be closer to the final aerodynamic configuration (much like Rafale A was to Rafale C and YF-22 to F-22 EMD). In this respect it will be closer to the actual GCAP demonstrator, which I believe is also slated to fly in 2029/30?

Then there's the question of how the final engines will be integrated... e.g. will the GCAP and FCAS demonstrators have built-in provisions for larger engines, either EJ200/M88 experimental derivatives (what EUMET calls a "Frankenstein" engine incorporating some of the new technologies), or will they be able to fit early prototypes of the final engine designs (which will be much larger)?

 

[djpowell1984]

For an aircraft/demonstrator that's 20.4m long. Powering it with 2x EJ200's seems a bit inadequate.

EJ200 is very powerful Engine; they were limited due to Eurofighter Typhoon's airframe limited to mach speed = 2.0 They could go more of it, if it give a not limited (ie it say could go more 2.3-2.5 maybe more, if the Airframe changing skins and frame strength, main is aluminium and carbon fibre which factor to limited speed and stress airframe, thermal on skin during high speed.)

They are the best class in thrust/weight. High is better (don't forget it is does small size too)

let compare them
--------------------------------------

F-15 engine is T/W is 7.92:1 (80Kn>140Kn) (F110) (they can't supercruise 571 mph) they need reheat to reach past the transonic
Length: 191 inches (485 cm)
Diameter: 34.8 inches (88 cm) inlet, 46.5 inches (118 cm) maximum external
Dry weight: 4,100 pounds lb (1,900 kg)

F-15 Engine can push to higher speeds and power F-15 (Around 20m), but the same issues as Typhoon reduce to 2.5 mach (they could go 2.8-2.9 mach, i think as they have been recorded for it) need to get Titanium to reach near Mach 2.8-3.5 (which MIG-25/31 they are has titanium compare to F-15)

-------------------------
F-22 Engine is T/W is Dry: 5.2:1 (intermediate), Reheat: 7.0:1 (afterburning) (110kn>160kn) (Around 20m) able Supercruise
Length: 196 in (497.8 cm)
Diameter: Approx. 40 in (100 cm) inlet, 48 in (120 cm) overall, 50 in (130 cm) maximum
Dry weight: Approx. 5,000 lb (2,270 kg) overall

limited speed to 2.2 due stealth (could up 2.5 then issues is Airframe need titanium, which could affect stealth - as thermal could create RCS high also material need travelled more that 2.5 will need replace LO to normal, useless there have secert stealthly high thermal coat technology/metamaterial)

-------------------------------

EF Engine is T/W Dry: 6.11:1 Reheat: 9.17:1 (60Kn>90Kn) also it more small and light than F110 and F119
Length: 398.78 cm (157.00 in)
Diameter: 73.66 cm (29.00 in)
Dry weight: 988.83 kg (2,180.0 lb)

That reason t/w best in size and light still good kN

I'm not sure what T/W dry and reheat rate if they push to (78kn>120Kn) with V2 EJ200, which put similar to kN class as F-15 Engine (it is equal in kN but yet more powerful t/w still beat F-15 Engine) possible supercruise for demonastor with new technology which F-15 Engine might cant able do,

also it will increase for EF in the term maximium cruise speed also low fuel to less reheat possible 1.5mach or more on EF due dry power more increase 60 to 78kn near 1/4 extra.

But i don't think Tempest Demonastor will not able touch supercruise range.

"What if" it Typhoon touches 2.0 mach supercruise, then they won't use reheat, as it will save lots of fuel, cant go more 2.0.

Yet they will use it (Reheat / wet / afterburner) for high speed boost from 0-2.0 mach, use high fuel, ie runway, or reach fast if needed, high accelerate (which it is more unlikely but who know as they has secert data or wartime EJ200 as i keep hear this term) for me 78kN i dont think it is will able to touch i think possible increase 1.1 to 1.3(mimimum) to (1.6/1.7 is maximium maybe low than it)

---------------------------------------
GCAP Engine

GCAP engine, they plan around dry: 120/140-150kn Reheat: 180-220kn which double EJ200 and near half more F-15 Engine but size and weight i don't idea..if middle both of EJ200 Engine and F-22 i will be shocked ( i think it will be around F-22 Engine yet powerfully than it) t/w not yet but would be good equal as ej200 in term t/w with high kN or more better in t/w

Off Topic (don't sure if it is relevant?

Phantom 2 (F.4) Engine is low T/W Engine 3.1 dry / 4.7 with afterburner

yet it still can reach 2.5 Mach they are around closer to 20m (but can't supercruise 571 mph same as F-15 to require to reach high speed they need reheat to reach past the transonic phase.

T/W Dry: 52.8 kN Reheat: 80Kn
Length: 208.69 in (5.301 m)
Diameter: 39.06 in (0.992 m)
Dry weight: 3,835 lb (1,740 kg)

close to similar class as EJ200, but they are heavy and very big. but low T/W

F-4 and F-15 cant supercruise T/W "my guess reason" is the Transonic phase, as they are is dangerous phase can affect airflow so wing and tail could lose control to hold the speed inside transonic range phase use dry power) that reason lots accident in early jet age and learn the lesson...

these are why cruise speed usually limted see is "below or above transonic" to better stabilty airflow to travelled;

as The engine couldn't power hold the speed to pass Transonic inside the reason which F22 is able due to massive powerfully engine high kN and T/W of Airframe able to 1.5-1.8 Mach Supercruise and Typhoon is able due small and light design compared to F22. as around half weight able pass "Transonic" to hold Supercruise 1.1-1.2

also FADEC is help deal fuel and Power to control air speed etc.

Please correct me if i wrong, as I'm not a specialist in this field and have limited knowledge of engineering. <- has been studied in college up to level 2,


Back to topic

They could no need to test supercruise yet cruise speed in subsonic 571 Mph range, and reheat to over mach 1 barrier same way late 3g/early 4g Pre-4.5+/4.75++Gen.

Possible hit 2 mach

It is fine if use for test purpose and data airflow and air pressure, fuel, weight, RCS, etc, until replace better engine is replaced (maybe with a prototype GCAP Engine or Japanese IHI XH-9 engine) put on a demonstrator before use on the GCAP Prototype / pre-producation. Able fly with ej200

Also new technology A.C.E will extra help save fuel and increase range, t/w

 

[H_K]

Phantom 2 (F.4) Engine is low T/W Engine 3.1 dry / 4.7 with afterburner yet it still can reach 2.5 Mach

I was about to mention the A-5 Vigilante... same J79 engine as the F-4 Phantom, but even bigger aircraft (15 tonnes empty, with a giant ~3,500 liter internal bomb bay/chute). The J79's thrust was similar to the Rafale's M88, i.e. ~10% less than an EJ200.

Yet it could still hit its operating Mach limit (M2.0-2.1) with 6 tonnes of internal fuel & weapons, and achieved Mach 2.5 during speed record attempts. At a 21.5 tonne combat weight its rate of climb was over 30,000 ft/min. Obviously the J79 was a turbojet, which helped a little at high Mach & high altitude, and the inlets were optimized for Mach 2, but an EJ200 or M88 should perform pretty well by comparison up to Mach 1.5-1.8.

So again... engine thrust would be OK for a demonstrator as long as no one is expecting it to set time to climb records or to demonstrate sustained turn performance.

P.S. Here's the A-5C Vigilante scaled against GCAP & F-15 (assuming GCAP at ~19.5m length)... if you removed the A-5's backseater and shortened its fuselage accordingly by 2.5ft/80cm you'd be very close in scale to GCAP... (except for the massive delta wing).

 

[Reuben James]

I was about to mention the A-5 Vigilante... same J79 engine as the F-4 Phantom, but even bigger aircraft (15 tonnes empty, with a giant ~3,500 liter internal bomb bay/chute). The J79's thrust was similar to the Rafale's M88, i.e. ~10% less than an EJ200.

Yet it could still hit its operating Mach limit (M2.0-2.1) with 6 tonnes of internal fuel & weapons, and achieved Mach 2.5 during speed record attempts. At a 21.5 tonne combat weight its rate of climb was over 30,000 ft/min. Obviously the J79 was a turbojet, which helped a little at high Mach & high altitude, and the inlets were optimized for Mach 2, but an EJ200 or M88 should perform pretty well by comparison up to Mach 1.5-1.8.

So again... engine thrust would be OK for a demonstrator as long as no one is expecting it to set time to climb records or to demonstrate sustained turn performance.

P.S. Here's the A-5C Vigilante scaled against GCAP & F-15 (assuming GCAP at ~19.5m length)... if you removed the A-5's backseater and shortened its fuselage accordingly by 2.5ft/80cm you'd be very close in scale to GCAP... (except for the massive delta wing).

View attachment 778146

The render of GCAP used in this comparison, is it representative of the final fighter?

 

[zen]

It does seem the design has a lot of wing....

 

[Scott Kenny]

It does seem the design has a lot of wing....

The concept art and models have a lot of wing.

I suspect it's because the fuselage is full of weapons bays and engine ducts, so the fuel for the range wanted goes in the wings.

 

[wiffy]

Are there any Italian attempts at advanced fighter development in the past?
Japan had the X-2 and XF9 engine, and the UK had the BAe Replica

 

[overscan (PaulMM)]

Please discuss the BAE Systems Combat Air Flying Demonstrator in the appropriate topic.

https://www.secretprojects.co.uk/threads/bae-systems-combat-air-flying-demonstrator.47436

 

[momosir]

I hope the British version Demonstrator is shown to the public with its first flight, to show it is on track. 2027 i'm look forward to this.

I'm think they will test for a few years with equipment test and future improvement, Ie EJ200 V2 76KN + 120 KN Reheat with test Electrical Generator + CAPTOR-E ASEA Mk 2, AR-VR Head up in a later date, like 2028-29, test update/upgrade (it definitely will not include AR-VR at start demonstrator as been mentioned)

Japan will have its Japanese versions, such as Engine Japanese and AESA Japanese, etc. when they will build and fly?

I'm not sure what Italian demonstrator? Maybe use British and Japanese to test their Plane? As I can't see any info about this.

Once both the completion test, etc and share data, then build the Second Demonstrator is the GCAP Demonstrator with a final version prototype as pre-production 2030. Then full production in 2035 is on track, as I don't want to see a delay.

What I like to see UK

UK build Minimum = 144 (would like to see we order Maximum = 216) GCAP Tempest for the UK for Heavyweight Multi-Role (Twin-Engines)
Focus on Long Range Strike and Long Range Fighter, Long Range QRA, Recon, Patrol.

Off the topic
It would be nice to add
Also, get a Minimum = 36 - maximum =72 of the TA-50 / F/A-50 (Block 70) Golden Eagle "Buzzard for UK name" for Lightweight Multi-Roles (single-engine)
Focus on Short Range QRA, Close Support & Training Jet, Patrol (low-cost), ie Coast Protection

Most important roles TA-50 (and) F/A-50 focus on anti-Drone Spawn or Cruise Mission roles (Shot down use CRV-7 PG / ASRAAM) to replace Hawk & Jaguar, Harrier. (Reason I pick this as they can go fast to 1.5-1.8 Mach it is fast trainer Aircraft bonus they have a quiet good range for UK) to Support GCAP also they could use EJ200 so we could re-purpose EJ200 (upgrade them to V2) From Eurofighter Typhoon to T&F/A-50

Also bonus they already include ASRAAM and Brimstone, Spear 3, and Meteor for integration are already included. (maybe worth add British radar CAPTOR-E Mk 2 if enough size for put in to this)

Keep backup Typhoon Tranches 3 to 2040-2045, also half of them toward to the Falkland Islands and other places.

also 96 F-35 "B" + (12 F-35 "A" <-- I think stupid move they potentially use it to cancel the GCAP use excuse reason later date to get more F-35 "A" 144 of them)

Loyal Wingman
1 GCAP per 2 or 4 (144 / 288 - 576 loyal Wingman) - Possible 288
1 F35 "B" per 2 or 4 (96 / 192 - 384 Loyal Wingman) - possible 192
Total Possible (1 per 2) 480 even Potential if 1 per 4 = 1392 Loyal Wingman

Back to Topic
Update JAGUAR (Uk-JP radar) Engines? etc?

Anti-Air Meteor MLU ? will improve Engine and AESA seeker? or will new AAM France-UK (what roles it will focus on? EXLR-AAM ? 300-400 miles for AWCAS and 200 Miles for Fighter? Hypersonic Speed?)

will how big Internal Bay so FC-ASW can fit inside? or will small cruise missile ie MAKO instead FC-ASW?

Japan has already completed the demonstration of a new AESA radar and IR sensor (先進統合センサ・システム). A modified F-2 was used for the test.
https://www.mod.go.jp/atla/research/ats2020/poster/kenkyu_01.pdf
This is the aircraft in question. The blue missiles are dummies attached for aerodynamic reasons, and the white missiles have the IR sensor.

The radar installed on the system is reportedly twice as far as the LM's（F-35）.

 

[Jackonicko]

Tailless is probably the optimal solution for Low Observability.

Whereas tails are the optimal solution for agility, etc.

 

[EmoBirb]

Since there hasn't been any recent news about GCAP, let me ask a question from a layman's perspective:
In the end, do next-generation fighters need tail fins? Or is a tailless design the optimal solution?

Ideally you'd have a tailless design for maximizing signature reduction, the "hopeless diamond", B-21, B-2 and all the tailless flying wing UCAVs emphasize that. China follows the example with their J-36 and "J-50".

Large, standing stabilizers like seen on virtually every GCAP model/render are far from ideal. Ruddervators like on the YF-23, LTS or FCAS renderings lend themselves to reducing the signature of an aircraft while maintaining large control surfaces for desired aerobatic performance (or perhaps having decent low speed behavior that would be necessary for carrier landings).

 

[TorpedoJ]

Ideally you'd have a tailless design for maximizing signature reduction, the "hopeless diamond", B-21, B-2 and all the tailless flying wing UCAVs emphasize that. China follows the example with their J-36 and "J-50".

Large, standing stabilizers like seen on virtually every GCAP model/render are far from ideal. Ruddervators like on the YF-23, LTS or FCAS renderings lend themselves to reducing the signature of an aircraft while maintaining large control surfaces for desired aerobatic performance (or perhaps having decent low speed behavior that would be necessary for carrier landings).

To the untrained eye (mine), there doesn't seem to be much difference between the fins on the GCAP renderings and those for SCAF.
Is it just the angle, or the fact that they are on top of the wing trailing edge? Or a combination of all of those things?

 

[Jackonicko]

Ideally you'd have a tailless design for maximizing signature reduction, the "hopeless diamond", B-21, B-2 and all the tailless flying wing UCAVs emphasize that. China follows the example with their J-36 and "J-50".

Large, standing stabilizers like seen on virtually every GCAP model/render are far from ideal. Ruddervators like on the YF-23, LTS or FCAS renderings lend themselves to reducing the signature of an aircraft while maintaining large control surfaces for desired aerobatic performance (or perhaps having decent low speed behavior that would be necessary for carrier landings).

The recent GCAP concepts have all had canted and 'shaped' vertical fins. Concept Class 5 more than the rest. The new demonstrator does not.

 

[H_K]

The recent GCAP concepts have all had canted and 'shaped' vertical fins. Concept Class 5 more than the rest. The new demonstrator does not.

I wonder if the fairly simplified straight edges on the demonstrator isn’t a deliberate way to hide some of the real shapes that they could end up on using on GCAP (which will almost certainly be more exotic)?

 

[FighterJock]

The actual complete design could change over time depending on what they discover during the course of the flight tests using the demonstrator aircraft.

 

[Scott Kenny]

Whereas tails are the optimal solution for agility, etc.

Probably. That may be changeable with TVC and fluidic controls.

 

[Reuben James]

Ideally you'd have a tailless design for maximizing signature reduction, the "hopeless diamond", B-21, B-2 and all the tailless flying wing UCAVs emphasize that. China follows the example with their J-36 and "J-50".

Large, standing stabilizers like seen on virtually every GCAP model/render are far from ideal. Ruddervators like on the YF-23, LTS or FCAS renderings lend themselves to reducing the signature of an aircraft while maintaining large control surfaces for desired aerobatic performance (or perhaps having decent low speed behavior that would be necessary for carrier landings).

What do you think are the reasons behind retaining the vertical stabilisers? BAE has experience with both tailless, stealthy designs and active flow control technology, so I don't think it would be unfeasable from an engineering perspective.

 

[Scott Kenny]

What do you think are the reasons behind retaining the vertical stabilisers? BAE has experience with both tailless, stealthy designs and active flow control technology, so I don't think it would be unfeasable from an engineering perspective.

My suspicion is that the GCAP design has a different RCS requirement than NGAD/F-47. Larger RCS that can be reached by a plane with vertical stabilizers, so they don't have to do all the engineering for TVC and active flow control.

 

[Nx4eu]

What do you think are the reasons behind retaining the vertical stabilisers? BAE has experience with both tailless, stealthy designs and active flow control technology, so I don't think it would be unfeasable from an engineering perspective.

Cost

 

[EmoBirb]

What do you think are the reasons behind retaining the vertical stabilisers? BAE has experience with both tailless, stealthy designs and active flow control technology, so I don't think it would be unfeasable from an engineering perspective.

I'm in no way qualified to make remotely accurate guesses, but if I were to make some my picks would be high speed stability and perhaps (as others already mentioned) less stringent goals with regards to signature reduction (aka leaning more so into "5.5th Gen" territory to stick with colloquial terms) which also reduces cost subsequently.

But maybe the final thing will be different, who knows (I certainly don't know).

 

[EmoBirb]

To the untrained eye (mine), there doesn't seem to be much difference between the fins on the GCAP renderings and those for SCAF.
Is it just the angle, or the fact that they are on top of the wing trailing edge? Or a combination of all of those things?

I can imagine the joint between the stabilizer and fuselage could lead to some funky reflections from the side. Not really the case with YF-23/LTS/FCAS tail designs.

 

[yeetmahboi]

What do you think are the reasons behind retaining the vertical stabilisers? BAE has experience with both tailless, stealthy designs and active flow control technology, so I don't think it would be unfeasable from an engineering perspective.

Tails may be straight up just more feasible and still fills the reqs, so tails it is.

 

[Maro.Kyo]

In this respect it will be closer to the actual GCAP demonstrator, which I believe is also slated to fly in 2029/30?

You're right that FCAS demonstrators will be closer to GCAP prototypes in nature, but they are absolutely not the same.

It's not a demonstrator but is going to be GCAP EMD prototype, representative of production model. That's pretty evident if you look at the envisioned programme schedule which has been posted on this thread before. Only "demonstrators" for GCAP would be the X-2 and the Team Tempest CAD effort. You could doubt if EMD prototype could fly within 5 years, since I doubt the same, but anyways, that's at least the plan. As I've wrote before, I think that a more realistic IOC is late 2040 plus-minus 3 years.

 

[Tomboy]

You're right that FCAS demonstrators will be closer to GCAP prototypes in nature, but they are absolutely not the same.

It's not a demonstrator but is going to be GCAP EMD prototype, representative of production model. That's pretty evident if you look at the envisioned programme schedule which has been posted on this thread before. Only "demonstrators" for GCAP would be the X-2 and the Team Tempest CAD effort. You could doubt if EMD prototype could fly within 5 years, since I doubt the same, but anyways, that's at least the plan. As I've wrote before, I think that a more realistic IOC is late 2040 plus-minus 3 years.

What good is IOC in the late 2040s especially for a lower spec'd 6th gen. By then leaders(US, China etc) will be flying next generation aircraft prototypes while their current 6th generation aircraft will probably have multiple major/minor upgrades to improve them even further.

 

[Scott Kenny]

What good is IOC in the late 2040s especially for a lower spec'd 6th gen. By then leaders(US, China etc) will be flying next generation aircraft prototypes while their current 6th generation aircraft will probably have multiple major/minor upgrades to improve them even further.

The US will be lucky to get the F-47 to IOC before 2040, IMO.

 

[TorpedoJ]

I can imagine the joint between the stabilizer and fuselage could lead to some funky reflections from the side. Not really the case with YF-23/LTS/FCAS tail designs.

Oh I see, it's that the tail meets the fuselage from above rather than on the side corner like YF23. Thanks, that makes sense.
With your '5.5gen' comment above, I think BAE are leaning into the software and sensor side of 6th gen rather than ultra stealth, and prioritising payload and range at the expense of RCS. They may be relying on Leonardo's EW expertise for survivability, and having enough weapons to take out secondary/defending targets on the ground instead of just flying in, dropping a bomb and leaving undetected.