Debate on F-35 JSF aerodynamics

[Aussie Digger]

No, it wouldn't. BAE would be responsible for such a sale (to Australia) and for support as well. So no strings attached here... BTW what about the NH-90 an and Tigers? Surely if Australia bought EFs they most likely would be provided with a very robust maintenance infrastructure or even become project members. But that's just fictional and very OT
Apart from that I can't imagine the German, Italian or Spanish government holding back spares for Australia. For some reason you guys are very popular here

I have a feeling that is why the Tiger's weapons (apart from the cannon) are US sourced. Afterall we have sufficient levels of support to FLY the helo in Australia, what would it matter WHERE we chose to fly it?

However if the weapons supply were turned off it'd impinge on our ability to operate them in the manner and places we so choose...

 

[Aussie Digger]

Mod edit: "And around and around we go"...

Ladies and Gentleman. The F/A-18E/F, F-22 and F-35 threads are going to be rested for several weeks. They are simply nothing around in circles and achieving nothing. The SAME arguments and opinions are being repeated over and over again.

This is the decision of the mods AND Webmaster. Please respect it and do not open new threads nor continue these discussions "off topic" in other threads.

The situation will be reviewed in several weeks.

Regards

AD.

 

[BKNO]

AGRA All this doesn't mean its better than the F-35, thats just crazed Gaullic ultranationalism,

It is Rafale. Rafael is an Israely Avionic company if i remember well.

Now; Looks like everything remotly informative is pure "crazed Gaullic ultranationalism" these days. isn't it?

We're getting used to this sort of assumption, it changes little to FACTS.

For the rest of the posts it's really not worth a reply, i'm sorry to say but you guys need to travel a little you're welcome in France to have a look at what is going on here other than forum legends and US desinformation...

 

[Ozzy Blizzard]

I agree. A lot of people have speculated that because the F-35's engine exhaust nozzle is "round" that it's somehow not stealthy. That may be the case (except we don't know for SURE of the production models shape) however implict in this argument is the idea that no advancements in LO technology have occurred in the time since the F-117, B-2 and F-22 were designed...

Perhaps it HAS. If it's true that LM IS holding back the final design of the engine nozzle from public view, it would tend to seem more credible to me.

In anycase it's hardly something that's going to be broadcast across the breadth of the Internet, is it?

You would have to assume with the heavy consideration given to low level survivability in the design of the F35 (EOTS, X band stealth) that the IR missile threat would have been at least somewhat adressed, and that would mean engin exhaust cooling as well as countermeasures.

Although AD i have to question your assumption that just becaus LM may have learned about LO technologies, that automaticaly the F35 will be more stealthy than it was designed to be. More comprehensive LO means more bucks, and due to the "low" nature of this platform in the force structure, i doubt they are going to want to put whiz bang stealth on it when it wasn't required in the design.

 

[Todjaeger]

Although AD i have to question your assumption that just becaus LM may have learned about LO technologies, that automaticaly the F35 will be more stealthy than it was designed to be. More comprehensive LO means more bucks, and due to the "low" nature of this platform in the force structure, i doubt they are going to want to put whiz bang stealth on it when it wasn't required in the design.

Given time (and additional work/development) sometimes LO techniques do end up performing better than originally designed. Depending on the hows & whys of the improvement it doesn't necessarily increase the cost. I don't have specific examples to cite but it's not unreasonable to think the JSF might have better LO characteristics than originally planned. Likely not to the extent of the F-22 but better than originally intended.

-Cheers

 

[Scorpion82]

i doubt they are going to want to put whiz bang stealth on it when it wasn't required in the design.

The JSFs design were also not required to use comprehensive onboard sensors, but rely more upon the networkcentric battlefield environment. Look what it is now. And don't forget about the associated cost increasements, though there're numerous other reasons for that as well.

 

[Ozzy Blizzard]

The JSFs design were also not required to use comprehensive onboard sensors, but rely more upon the networkcentric battlefield environment. Look what it is now. And don't forget about the associated cost increasements, though there're numerous other reasons for that as well.

If there are more efficient ways to achieve a lower RCS in specific wavelengths for the same or similar bucks, then yes I agree the F35 will be more stealthy than it originaly was. However you cant assumethat it will have comprehensive stealth, just because LM know how to do it on other platforms, even though its not one of the design peramiters. Just because LM know how to make it better, doesent automaticaly mean it will be. Platforms are designed to meet a specific set of requirements for a specific price, and that equasion may have changed somewhat but dont think it'll be the best thing in the world because it could be. For one thing its primarily a strike platform, and will be the most outstanding CAS/BID platform ever created, but i dont see how that automaticaly translates to outstanding A2A performance as the manufacturors are now saying. All of its systems have most of their design geared toward strike. It wont be great at things it wasn't designed to be great at. Thats my point.

 

[vivtho]

AD had read about the IR suppression tech on the Nighthawk it talked of making the nozzle CS profile rectangular this makes the exhaust plume leave the A/C resembling a rect. "sheet" reducing the detection angle on or about the horizontal plane of the aircraft. The initially round cross-section expands into a two-dimensional (rectangular shape) exhaust nozzle and in a side view has a very shallow S shape. The unusual aspect of the design is the incorporation of a coanda surface in the rectangular section that shields the turbine section of the engine when looking into the nozzle. Because the exhaust duct is internally mounted within the fuselage of the aircraft, its length can be very long and it can be semi-rigidly mounted therein. (info.... US patent 5699662).


One can assume that technology might have matured to a different level by the time F-35 and F-22 programmes were concieved and hence they would incorporate something similar or better than the techniques described above.

Won't a long nozzle like you described above lead to increased loss of thrust. I am not an expert in this field, but I do know that early aircraft (best example de Havilland Vampire) were optimized with as short a nozzle as possible to minimise this loss. Even modern fighters continue to keep the engine at the extreme rear of the aircraft for a similar reason.

Also, will the Marine version of the JSF use the same nozzle. The design described above seems incompatible with the requirement for vectored thrust.

 

[vivtho]

And THEN you'd need the French to continue to support the system in times of crisis where we are engaged in a scenario which doesn't necessarily correspond to their foreign policy, something the RAAF (and Israel and others) have learned the hard way in the past! On the other hand, if we had to take the F-35 or F/A-18F to war tomorrow, you just know the US would have a C-17 full of spares here by the end of the week.

Why do you think we sent Canberras to Vietnam instead of Mirages??? And why did Israel and South Africa develop their own indigenous versions of the Mirage?

I suspect the Typhoon would have similar 'strings' attached to it unless a deal could be done directly and solely with BAE instead of with the multi-national Eurofighter consortium.

Decisions about equipment procurement are far more than just the platform's capability and price - the political side of the deal is a huge consideration.

Cheers

Magoo

That's gonna happen no matter which country you buy it from. Just a few examples...

1. France: Denied sales Mirage IIIs and spares to Israel after 1967 war.
2. USA: Arms embargo on Argentina after the Falklands war. Arms embargo on India after nuclear tests. Arms embargo on Pakistan after nuclear tests. The Pressler amendment blocked deliveries of F-16s that were already paid for.
3. Russia: Stopped parts delivery on T-80 components sold by Ukraine to Pakistan. Stopped assistance to China on development of JF-17 fighter.
4. Italy: Stopped sale of aircraft components to China after Tienamen square massacre.

Military sales are one of the ways a nation imposes it's foreign policy. The only way out is for a country to develop it's weapons indegenously.

Just my $0.02.

 

[Scorpion82]

If there are more efficient ways to achieve a lower RCS in specific wavelengths for the same or similar bucks, then yes I agree the F35 will be more stealthy than it originaly was. However you cant assumethat it will have comprehensive stealth, just because LM know how to do it on other platforms, even though its not one of the design peramiters. Just because LM know how to make it better, doesent automaticaly mean it will be. Platforms are designed to meet a specific set of requirements for a specific price, and that equasion may have changed somewhat but dont think it'll be the best thing in the world because it could be. For one thing its primarily a strike platform, and will be the most outstanding CAS/BID platform ever created, but i dont see how that automaticaly translates to outstanding A2A performance as the manufacturors are now saying. All of its systems have most of their design geared toward strike. It wont be great at things it wasn't designed to be great at. Thats my point.

I see we have a similar opinion here. I'm not saying the F-35 is going to be a super duper AA platform as the F-22 is, because of costs and different requirements. But I say some things can change over the developement cycle of an aircraft. That doesn't mean that you receive a completly different platform at all.

 

[Aussie Digger]

You would have to assume with the heavy consideration given to low level survivability in the design of the F35 (EOTS, X band stealth) that the IR missile threat would have been at least somewhat adressed, and that would mean engin exhaust cooling as well as countermeasures.

Although AD i have to question your assumption that just becaus LM may have learned about LO technologies, that automaticaly the F35 will be more stealthy than it was designed to be. More comprehensive LO means more bucks, and due to the "low" nature of this platform in the force structure, i doubt they are going to want to put whiz bang stealth on it when it wasn't required in the design.

And what was F-35 designed LO level meant to be?

Can you please tell me because I'm SURE it's published on the WWW...

Funny how the USAF describes the F-35A as a "first day of war" asset designed specifically to go head into "modern IADS and win"...

Check out what General DAVIS has to say about it:

The one thing we also do not necessarily talk too much about on the F-35 is the fact that it is a day one platform in the most stressing scenarios. There is a difference in how we would attack a day one target set out there as opposed to how the F-22 would do it. Obviously we use a little bit different formation. We may even use more airplanes to go out and attack those very high value, very high threat targets. But we do have an ord requirement to be able to do those missions and right now we have no real, if you will, challenge meeting those missions. That’s where we get into how the stealth employs, how the electronic attack capabilities and different things on the airplane work.

 

[Ozzy Blizzard]

And what was F-35 designed LO level meant to be?

Can you please tell me because I'm SURE it's published on the WWW...

Right, we dont know the exact specifcations. But that somehow translates to B2 like LO hugh? Even though it was designed by LM to have a narrowband stealth that's purpose is to defeat X band fire control and search radars? Requirements=Design=Costs. Not just because its new it'll have evenrything and be awesome at everything.

Funny how the USAF describes the F-35A as a "first day of war" asset designed specifically to go head into "modern IADS and win"...

Check out what General DAVIS has to say about it:

The one thing we also do not necessarily talk too much about on the F-35 is the fact that it is a day one platform in the most stressing scenarios. There is a difference in how we would attack a day one target set out there as opposed to how the F-22 would do it. Obviously we use a little bit different formation. We may even use more airplanes to go out and attack those very high value, very high threat targets. But we do have an ord requirement to be able to do those missions and right now we have no real, if you will, challenge meeting those missions. That’s where we get into how the stealth employs, how the electronic attack capabilities and different things on the airplane work.

Im not suprised at all that the USAF intend to use this 5th generation joint STRIKE fighter to penitrate decent IADS and hit high value targets, since IADS rely on x band fire controll radars that the F35's LO was specificaly intended to defeat. I would assume that the F35 would rely more heavily on EA than the F22 to defet long range VHF radars. But penitrating an IADS doesent automaticaly equate to B2 LO.

The point about EA is very interesting. You would assume given the advances made in US AESA's, notably the APG 79, the APG 81 would have a very mature EA capability. An ability to interupt datalinks, comms, and radar to cover non LO assets or disable lower frequency radars would be devistating when coupled with the platforms LO. It will indeed be a feasome strike platform. However it will still be vulnerable to advanced EO/IR, but less so if the detecting platfoms comms are interupted.

 

[Grand Danois]

The F-35 is optimised for the X-band range, but what is there to suggest it is not stealthy in the low-frequency ranges?

Internal munitions bay, obvious shaping, angled tailfins, bandpass nosecone (particularly effective vs search radars), serrated edges, goldtinted canopy, buried engine, etc.

The manufacturing tolerances for the X-band would also help in the other bandwidths.

Plus the multigenerational stealth knowledge that the aircraft will inherit.

Why wouldn't the F-35 be in the -10 to -20 dB RCS range vs search radars?

Already at -10 dB the RCS would be basketball sized, which is still stealth, though not bird- or insectsized.

 

[Ozzy Blizzard]

You would have to assume that the F35's LO is still effective at lover wavelengths, just less so. I read an article which stated that the lower the wavelength the less effective the LO, which i'm guessing is similar for most LO aircraft after a certain point,due to the sheer size of the wave's ( i would post the link but i dont want to get into one of those arguments again ). Even at VHF or HF, just due to shaping and internal weapons you would assume it would have a lower RCS than legacy fighters. I wasn't disputing that.

However i was disputing the notion that the F35 would be anywere near as capable at defeating lower wavelength radars as the F22/B2.

 

[Grand Danois]

However i was disputing the notion that the F35 would be anywere near as capable at defeating lower wavelength radars as the F22/B2.

I certainly wouldn't make that argument either. F-22A/B2 are uncrompromising in their approach to VLO.

 

[Aussie Digger]

Right, we dont know the exact specifcations. But that somehow translates to B2 like LO hugh? Even though it was designed by LM to have a narrowband stealth that's purpose is to defeat X band fire control and search radars? Requirements=Design=Costs. Not just because its new it'll have evenrything and be awesome at everything.

I don't recall stating that, but given we don't know the B2's exact capability, this would appear to be a non-sequitur wouldn't it?

I don't and never have suggested the F-35 will be the best at "everything". What I do think it will be, is the best SINGLE FIGHTER for the RAAF in coming years, given the breadth of roles the RAAF is required to perform.

Could the RAAF technically be enhanced beyond this by the inclusion of F-22 or some other "high end" fighter? Probably.

Will the budget exist though to do this? Unlikely.

Im not suprised at all that the USAF intend to use this 5th generation joint STRIKE fighter to penitrate decent IADS and hit high value targets, since IADS rely on x band fire controll radars that the F35's LO was specificaly intended to defeat. I would assume that the F35 would rely more heavily on EA than the F22 to defet long range VHF radars. But penitrating an IADS doesent automaticaly equate to B2 LO.

The point about EA is very interesting. You would assume given the advances made in US AESA's, notably the APG 79, the APG 81 would have a very mature EA capability. An ability to interupt datalinks, comms, and radar to cover non LO assets or disable lower frequency radars would be devistating when coupled with the platforms LO. It will indeed be a feasome strike platform. However it will still be vulnerable to advanced EO/IR, but less so if the detecting platfoms comms are interupted.

As will every OTHER platform. The F-35 though has the ability to employ standoff weapons from it's internal bays, to ranges that the F-22 cannot match with ANY weapon in it's inventory...

Ground based EO/IR systems are going to be LOS limited, which probably explains why they don't seem to be employed on anything besides MANPADS and AAA, though I am happy to be corrected on this point. I am certainly no expert in this field nor have I read extensively on it, but I believe this to be the case at present.

 

[BKNO]

@Aussie Digger

You are making assumption which are based on false datas.

Optronics and IR/technologuies are not equaly advanced in the US and the EUs to start with, they still are using mid-waves...

As they know too well since they choose to protect their ships with our Optronics for its all-weather performances.

Something else i think i can recall you stating that the F-135 nozzle design wasn't definitive.

You are simply wrong. There is NO further IR reduction design features in the pipeline for F-135/136, or else you know something thet even L-M doesn't...

 

[alexsa]

@Aussie Digger

You are making assumption which are based on false datas.

Optronics and IR/technologuies are not equaly advanced in the US and the EUs to start with, they still are using mid-waves...

As they know too well since they choose to protect their ships with our Optronics for its all-weather performances.

Something else i think i can recall you stating that the F-135 nozzle design wasn't definitive.

You are simply wrong. There is NO further IR reduction design features in the pipeline for F-135/136, or else you know something thet even L-M doesn't...

Pretty strong counter. do you have the inside knowledge of the JSF project and what L-M has planned to be sure of this or is it your opinion.

 

[Occum]

Budget already exists . . . .

Will the budget exist though to do this? Unlikely.

Dear Aussie Digger,

Not much point talking budget if you are not prepared to sensibly discuss the figures.

The simplest of arithmetic shows that more than enough budget already exists to provide Australia with the best air combat capability, in the most cost effective way and at the lowest risk while ensuring the Australian Defence Aerospace Industry remains intact.

Though now a little out of date and still awaiting final input from the peer review by Defence (some has already been received), you will find the bulk of the budget figures in the Total Project Cost Comparison table at -

http://www.ausairpower.net/media.html

The now $31+ billion already required to support the Minister's current plans (the F/A-18F interim solution was not a Defence recommendation nor decision so this should not be sheeted back to them) for the next 13 years is more than adequate to cover the greater capability of the F-22/Evolved F-111 Option and still leave well over $10 billion in the capability development kitty.

Realise you are likely to disagree, so let's see the results plus associated references and assumptions of your costing analysis. Nothing like a bit of professionalism to spur on a good debate.

 

[Aussie Digger]

@Aussie Digger

You are making assumption which are based on false datas.

Optronics and IR/technologuies are not equaly advanced in the US and the EUs to start with, they still are using mid-waves...

As they know too well since they choose to protect their ships with our Optronics for its all-weather performances.

Something else i think i can recall you stating that the F-135 nozzle design wasn't definitive.

You are simply wrong. There is NO further IR reduction design features in the pipeline for F-135/136, or else you know something thet even L-M doesn't...

Tell me why BKNO, it's what you CONSISTENTLY fail to do. BACK UP what you say with SOMETHING.

Tapping your nose and saying trust me gets you nowhere.

I never said the exhaust nozzle wasn't definitive. I said none of US have seen it the production nozzle YET. Hence the limited value in any analysis of the aircraft. A representative production aircraft hasn't even been BUILT yet.

AA-1 doesn't have the "weight loss" for a start...