The F-35 Thread

[Vault]

It was reported that stealth was not compromized. The data was sensitive but not 'Top Secret' sensitive. 'Classified' can be NOFOR - like a lot of the -1's.

 

I didn't think they released the details of what highly sensitive data was compromised.

 

No, it isn't - not even remotely. The interesting thing rather is that the RCS is small even against those, so range is limited - further, it is mostly the X-band that actual threat radars operate in (the ones that can guide weapons at you) and that is the most interesting part of the radar range for a stealth fighter.

They might see you, but they'll have trouble putting weapons on you while you'll be lobbing HARMs/SDBs/JDAMs at them.

If I understand correctly Physics dictates that the receiving antenna needs to be a minimum of 50% of the size of the wavelength. Now lets say the JSF is roughly about 15 metres in length, that would mean the JSF is physically incapable of carrying an antenna that is capable of picking up wavelengths in excess of 30 metres, so not only can the JSF be tracked by VHF radar, the JSF's RWR would fail to alert the pilot that he's being tracked, if you can't receive the wavelength you also can't jam it, You're correct FC, SAHR and ARM all use centimetric X band radar because of the accuracy it offers but I'm 99.9% sure that VHF radar is accurate enough to guide a DL IR missile through a fighter that is DL to a ground based VHF radar into a very small killbox considering old school Soviet ground based tracking radars used VHF, also at what range/aspect does an X band ARM seeker head have to to the JSF to effectivley "burn through" the JSF's range/aspect VLO parameters? At the very least you will be able to vector a non emitting interceptor/fighter at the JSF through DL for an attack. So yes it's interesting, very interesting if the JSF is vulnerable to VHF radar.

 

If I've got something wrong please feel free to correct me.

Edited June 18, 2009 by Vault

[Vault]

Sorry Vault, i dont have the data but i know where i have to ask if there are any. I will come back to you with an hopefully positive answer :)

 

Thanks for offering to look for it. I hope you find it. ;)

[GGTharos]

I didn't think they released the details of what highly sensitive data was compromised.

 

Yes, they did. It was maintenance/BIT program data.

 

 

If I understand correctly Physics dictates that the receiving antenna needs to be a minimum of 50% of the size of the wavelength. Now lets say the JSF is roughly about 15 metres in length, that would mean the JSF is physically incapable of carrying an antenna that is capable of picking up wavelengths in excess of 30 metres, so not only can the JSF be tracked by VHF radar, the JSF's RWR would fail to alert the pilot that he's being tracked, if you can't receive the wavelength you also can't jam it.

 

However EWS aircraft can pick it up and jam it. Further AFAIK those radars are just naturally susceptible to clutter. Anything that can carry and operate a VHF radio can pick up and jam a VHF radar. Such a site would likely be the prime target of a SEAD mission.

 

 

You're correct FC, SAHR and ARM all use centimetric X band radar because of the accuracy it offers but I'm 99.9% sure that VHF radar is accurate enough to guide a DL IR missile through a fighter that is DL to a ground based VHF radar into a very small killbox considering old school Soviet ground based tracking radars used VHF, also at what range/aspect does an X band ARM seeker head have to to the JSF to effectivley "burn through" the JSF's range/aspect VLO parameters? At the very least you will be able to vector a non emitting interceptor/fighter at the JSF through DL for an attack. So yes it's interesting, very interesting if the JSF is vulnerable to VHF radar.

 

If I've got something wrong please feel free to correct me.

 

If an X-Band radar is considered to be less accurate guiding a missile in TWS (With just a couple seconds between updates, too), then I think your VHF radar is pretty much a no-go, or at least pretty low Pk. I also think that, for the same reason, it would probably just get attacked with SDBs or something similar from afar when possible.

 

I'm not sure what you mean about an ARM seeker - do you mean ARH? An ARH missile is low Pk vs. a VLO/Stealth aircraft under the right circumstances (ie. for the JSF, front quarter) - IIRC there was in fact a study of AMRAAM vs. F-22 and while you can use a 120 vs. an F-22, it's low Pk. The study was mostly concerned with developing anti-stealth capability by the time opposing forces develop their own stealth aircraft. In short, the conclusion was that current (and near future) radar missiles have poor performance against VLO aircraft. I believe that among other things, the AIM-120D two-way datalink helps rectify some of this.

 

And yes, you could vector a fighter to it and that might be your best option. The flip side is that the JSF will be told by its own AWACS that it has fighters incoming, and then it's potentially a VLO vs. conventional fighter shoot-out ... assuming the JSF self-escorts at this point, as opposed to an F-22 coming in to mop up for you.

 

I'll say again though that this isn't interesting at all - at least for me - it was pretty much a known thing - the 'VHF will defeat all that is stealth' myth has been going around for a while. I find it difficult to believe that the designers of those aircraft would not heed it.

 

Another potential factor is that VHF radar sides tend to be relatively immobile when compared to an X or even L-band using SAM. The point behind this is that they're prime targets once fixed by say, a rivet joint.

[topol-m]

Y

 

An ARH missile is low Pk vs. a VLO/Stealth aircraft under the right circumstances (ie. for the JSF, front quarter) - IIRC there was in fact a study of AMRAAM vs. F-22 and while you can use a 120 vs. an F-22, it's low Pk. The study was mostly concerned with developing anti-stealth capability by the time opposing forces develop their own stealth aircraft.

 

 

I wonder what will be used against PAK-FA assuming its RCS will be similar to the one F-22/F-35 has?

[GGTharos]

An opening in the canopy for your pistol :D

[topol-m]

An opening in the canopy for your pistol :D

 

LOL :lol: i knew technology would lead us to this one day... :)

[Vault]

Yes, they did. It was maintenance/BIT program data.

 

Thanks for the reply GG, I didn't know that it was maintenance and BIT program data that was compromised in the hack.

 

However EWS aircraft can pick it up and jam it. Further AFAIK those radars are just naturally susceptible to clutter. Anything that can carry and operate a VHF radio can pick up and jam a VHF radar. Such a site would likely be the prime target of a SEAD mission.

 

FC/search LPI radars are not limited to decimetric and centimetric radar frequencies, AFAIK if VHF can detect the JSF then so can UHF, GG do you think that if an emitter is able hop between VHF and UHF frequencies, change phases and operate over the massive spectrum of wavelengths that VHF and UHF utilizes, it would make jamming extremely difficult?, I think it would be extremely difficult to jam. Yes VHF's are more susceptible to clutter, filters can help towards some of the clutter, also if a track appears on a VHF scope but fails to appear on an X band scope it would effectively become a type of NCTR against 5th gen fighters, which would make you a high priority target.

 

If an X-Band radar is considered to be less accurate guiding a missile in TWS (With just a couple seconds between updates, too), then I think your VHF radar is pretty much a no-go, or at least pretty low Pk. I also think that, for the same reason, it would probably just get attacked with SDBs or something similar from afar when possible.

 

I agree VHF would make a very poor TWS type of missile guidance, software and processing power could improve VHF's accuracy though, I do believe that VHF is sufficiently ample to guide a missile with a dual ARH IR seeker to be flown near enough to the JSF to acquire it and initiate terminal homing.

 

I'm not sure what you mean about an ARM seeker - do you mean ARH? An ARH missile is low Pk vs. a VLO/Stealth aircraft under the right circumstances (ie. for the JSF, front quarter) - IIRC there was in fact a study of AMRAAM vs. F-22 and while you can use a 120 vs. an F-22, it's low Pk. The study was mostly concerned with developing anti-stealth capability by the time opposing forces develop their own stealth aircraft. In short, the conclusion was that current (and near future) radar missiles have poor performance against VLO aircraft. I believe that among other things, the AIM-120D two-way datalink helps rectify some of this.

 

Yep, I meant ARH it's a typo, the JSF will be optimal against X band radar especially in a head on aspect, an ARH missile will always have a lower PK against the JSF, but I think as the range decreases and the side on aspect increases the PK will increase, but the PK will always remain lower against the JSF at any given distance when compared to the RCS of 4th gen aircraft, I think you can raise the PK of a missile considerably against the JSF by utilizing dual seekers for terminal homing amd a dog leg flight path for the missile.

 

And yes, you could vector a fighter to it and that might be your best option. The flip side is that the JSF will be told by its own AWACS that it has fighters incoming, and then it's potentially a VLO vs. conventional fighter shoot-out ... assuming the JSF self-escorts at this point, as opposed to an F-22 coming in to mop up for you.

 

If you can vector an interceptor/fighter through DL then you can vector a DL'd missile, it would form a poor TWS type of guidance with an intercept path that is more inefficient than an X band guided missile, but I think a missile that utilized a dual ARH/IR seeker head for terminal guidance seeker would give an acceptable PK. If the JSF is vulnerable to VHF/UHF is the F-22 also vulnerable to VHF?.

 

I'll say again though that this isn't interesting at all - at least for me - it was pretty much a known thing - the 'VHF will defeat all that is stealth' myth has been going around for a while. I find it difficult to believe that the designers of those aircraft would not heed it.

 

GG you have put across some very valid points, but I think it's a bit naive to dismiss a technology that is possibly able to track the JSF considering that the JSF is reliant on VLO technology for its survival, as we already know VHF has already indirectly attributed to the shooting down of an aircraft that utilized VLO technology, I used to be as confident as you are about VLO technology, but I no longer think VLO technology is invulnerable to all frequencies.

 

Another potential factor is that VHF radar sides tend to be relatively immobile when compared to an X or even L-band using SAM. The point behind this is that they're prime targets once fixed by say, a rivet joint.

 

True.

Edited June 18, 2009 by Vault

[GGTharos]

I think it would be extremely difficult to jam.

 

I think it would be far easier than any fighter's AESA antenna personally - but I could certainly be wrong on this one.

 

I agree VHF would make a very poor TWS type of missile guidance, software and processing power could improve VHF's accuracy though, I do believe that VHF is sufficiently ample to guide a missile with a dual ARH IR seeker to be flown near enough to the JSF to acquire it and initiate terminal homing.

 

No such thing as a dual guidance SAM exists AFAIK, with the potential exception of the SM-3, and I fail to recall if that is what it actually is.

It's easy to say 'could be flown near enough to initiate terminal homing' but so far opinion of parties close to the matter has been and even an X-band radar providing you with this guidance is a crummy proposition; how will the VHF radar know it's not guiding into a bunch of chaff? For that matter, does it even stand a chance of datalinking quality data to the missile allowing it to tell the real target from chaff or other CM's?

And then, what if your opponent just deploys a bunch of TALDs and yougive up all your SAM locations this way? It's simply not accurate enough to guide anything, and AFAIK no system currently exist to try and use it this way. Further, again, the ranges of those radars aren'te xactly ground-breaking either, and stealth does work against them.

 

 

Yep, I meant ARH it's a typo, the JSF will be optimal against X band radar especially in a head on aspect, an ARH missile will always have a lower PK against the JSF, but I think as the range decreases and the side on aspect increases the PK will increase, but the PK will always remain lower against the JSF at any given distance when compared to the RCS of 4th gen aircraft, I think you can raise the PK of a missile considerably against the JSF by utilizing dual seekers for terminal homing amd a dog leg flight path for the missile.

 

Side aspect drecreases Pk generically. As for a missile on a datalink, first of all your missile needs to be located where such a launch may occur; second, the scanning basket of a missile just isn't the same as that of the Mk-1 eyeball.

 

It's known that the JSF has its issues (namely, stealth is not really all-aspect), but claiming VHF=magic solution just ... doesn't seem to cut it.

 

 

 

If you can vector an interceptor/fighter through DL then you can vector a DL'd missile, it would form a poor TWS type of guidance with an intercept path that is more inefficient than an X band guided missile, but I think a missile that utilized a dual ARH/IR seeker head for terminal guidance seeker would give an acceptable PK. If the JSF is vulnerable to VHF/UHF is the F-22 also vulnerable to VHF?.

 

I don't know what you mean by 'vulnerable'. As you lower frequency apparent RCS becomes greater, yes, but you pay for it - less frequency = less accuracy, and still the RCS IS reduced compared to non-VLO aircraft. I'll point out there exist low-frequency radar brochures out there that specify detection ranges of low RCS targets and they're not terribly impressive. Dangerous, but not 'oh no stealth is useless'. And while they can datalink a position to a fire control radar, THEY are not FCRs.

 

 

GG you have put across some very valid points, but I think it's a bit naive to dismiss a technology that is possibly able to track the JSF considering that the JSF is reliant on VLO technology for its survival, as we already know VHF has already indirectly attributed to the shooting down of an aircraft that utilized VLO technology, I used to be as confident as you are about VLO technology, but I no longer think VLO technology is invulnerable to all frequencies.

 

I'm not dismissing it, I make the claim that the VHF thing is as over-hyped as 'EOS pwns F-22'.

The shooting down of the F-117 required the moon and the stars to line up, and you know it ;) It's ETA was known, it was detected at the time they thought they'd be able to detect it, and it was launched upon using a missile that was not a homing weapon. It really wasn't anything more special than taking a heli out with a TOW -- that's my opinion anyway.

[Vault]

GG if you want an example of a very impressive UHF radar look up the USN's UESA, the USN's UESA entered LRIP in 2006, for a UHF based radar it's very impressive. UHF also has a higher resistance to jamming than radar operating in the microwave region. A USEA will also have a higher LPI capability when compared to a X band LPI AESA.

 

The point I'm trying to make is that there is currently a LRIP batch of operational LPI UESA OTH radars in the US inventory, which is capable of handing off accurate hi rate targetting data remotely against low RCS targets. Systems like these are very dangerous to the JSF if it is suseptible to VHF.

 

I'm not advocating that "VHF/UHF kills JSF" and I'm not saying "VHF/UHF" is magical, I'm remaining neutral, but I'm up for a discussion on it.

Edited June 19, 2009 by Vault

[GGTharos]

Interesting, thanks for the info - I don't have much time to look for things but so far the plan appears to be hand-off to X-Band radar for target engagement.

 

The radar is in the S-Band and is being designed to aid with missile defense (they didn't specify what sort, but my guess is those nasty supersonic anti-ship missiles). We're looking at cross sections of 0.5m^2 in this case I think, but don't quote me on that.

 

So then it is apparently effective, at least if the LRIP means anything - but they aren't really making any statements about stealthy targets yet, just low RCS.

 

Hm, after looking at a bunch of other UHF radars it seems to me that they've not got much on stealth aircraft.

[Vault]

GG if the JSF is susceptible to VHF it will also be susceptible to UHF, UHF can impart more energy onto a given surface for longer periods of time than VHF that's why the USN's UESA uses UHF and not VHF, the really interesting part is that the first USN E-2D Advanced Hawkeye codenamed Delta 1 is carrying the full RMP upgrade which consists of the UESA radar backed up by a highly advanced IRST surveillance system made by Raytheon. Delta 1 has passed its second preliminary design review and its looking like the UESA in the RPM upgrade is here to stay. The fact that UESA offers sufficient precision for OTH remote targeting against fast moving targets with a low RCS is very impressive.

[GGTharos]

The reason these frequencies are being used, as I understand, is because you can actually pump more power through those systems compared to X-Band etc.

 

More power means better signal return - the frequency itself doesn't seem to have much to do with it ... but I wouldn't bill it as 'anti-stealth' yet.

 

The way I've seen it implemented is hand down to X-Band FCRs, which makes sense. The VHF/UHF radars however still don't appear to be enough of a threat against stealth aircraft - they raise the bar a bit, but right now stealth is still taking the cake. That's my take on it.

[Vault]

The frequency is very important GG, because of the frequencies wavelengths. The picture that Groove posted is visually stating that the JSF offers no VLO protection against VHF radar, the JSF will have a much larger RCS under the scrutiny of an UESA compared to an X band AESA, the JSF RCS & VLO performance figures against X band radar are not applicable to a UHF radar, when an object is under the scrutiny of UESA it uses an electronically steered narrow beam to emit a CW of UHF radar that offers sufficient high rate update precision to support remote targeting of an object with a low RCS.

Edited June 19, 2009 by Vault

[GGTharos]

In this case it doesn't appear to be so. The range gain appears to be primarily due to the sheer amount of kW coming out of that antenna.

You will still get an earlier detection, but the main reason seems to be more power.

[StewJW]

A popular thread, I'm unsure about the F-35, but the future of the UK Fixed Wing Fleet Air Arm will depend on its success. I

 

All this stealth business seems a lot of nonsense to me when what you need in a ground attack aircraft is speed, and the ability to carry a lot of ordinance so it can patrol an area for long periods suppressing enemy ground forces. Other aircraft like the UK Typhoon, also a ground attack aircraft, can look after aerial defence. Does the Navy really need the F-35?

[GGTharos]

The stealth business is for day one 'kick down the door' business. :)

[joey45]

A popular thread, I'm unsure about the F-35, but the future of the UK Fixed Wing Fleet Air Arm will depend on its success. I

 

All this stealth business seems a lot of nonsense to me when what you need in a ground attack aircraft is speed, and the ability to carry a lot of ordinance so it can patrol an area for long periods suppressing enemy ground forces. Other aircraft like the UK Typhoon, also a ground attack aircraft, can look after aerial defence. Does the Navy really need the F-35?

 

speed isn't everything, no one wanted the Harrier [apart from the USMC] then after the Falklands War look who has it now. The A10 is slow and it is the purfect CAS. The Typhoon [2] would be good for the Ground attack role / precion bombing.

 

And as for the F-35 > over budget and its replacing something that aint broke - the Harrier and unfortantaly the Jaguar which just got upgraded then scraped about 15 years before it should of for a harrier that can go supersonic... sence when has terry [taliban] got radar to shoot down a stelth plane. Sorry but no is the answer.

[GGTharos]

Who cares about the taliban? They're not the only threat around. If you only fights wars in the present or heavens forbid in the past, you're hosed.

 

And as for the F-35 > over budget and its replacing something that aint broke - the Harrier and unfortantaly the Jaguar which just got upgraded then scraped about 15 years before it should of for a harrier that can go supersonic... sence when has terry [taliban] got radar to shoot down a stelth plane. Sorry but no is the answer.

[StewJW]

Joey, Speed is important for a ground attack aircraft in modern conflicts. You should read some first hand accounts of the current conflict in Afghanistan. The longer it takes for air support to get to you the more lives will be lost. This is one advantage of the F-35 over the Harrier but the Typhoon is better and faster than both. It will be interesting to see how well the Typhoon performs when its sent over there. For long term loitering over the battle field nothing is better than a remotely controlled aircraft. I think the A-10 and the Harrier have sadly had their day. Even ground attack helicopters seem too vulnerable to ground fire. Some accounts I've read have seen Apaches having to leave the battlefield due to the risk of attack by RPGs!

Edited July 9, 2009 by StewJW

[GGTharos]

Actually the Typhoon doesn't do it better; the F-35 does. It is specifically designed to do the air to ground job better. As for the Harrier, the F-35 lifts twice the weapons to twice the range when doing VTOL operations, and kills fewer pilots/planes due to VTOL operation mishap.

[StewJW]

Time will tell. I'm all for new aircraft development but the F-35, in all its proposed variants, seems to be one of those political compromises which never quite match expectations. But what do I know, we'll see. At least the Typhoon is now seeing active duty after a very long development period.

[GGTharos]

The Typhoon is designed to be an interceptor and air to air fighter first and foremost.

 

The F_35 has all it needs to do A2G already built-in, and does not require supersonic speed and all that other jazz ... its optimized for the A2G role, and it'll do it well. ;)

[Groove]

F-35 STOVL refueling probe tests

 

[Groove]

"Dirty" F-35:

 

[joey45]

The Typhoon is designed to be an interceptor and air to air fighter first and foremost.

 

The F_35 has all it needs to do A2G already built-in, and does not require supersonic speed and all that other jazz ... its optimized for the A2G role, and it'll do it well. ;)

 

What about the Ground Attack [fGR] version thats being done?????