Operational Performance Comparison: Viper, Beagle and Stubby

[optimist]

When you drop an external tank. They say you light up like a xmas tree on radar. Would they have resolved the fuel vapour issue yet?

[spazsinbad]

When you drop an external tank. They say you light up like a xmas tree on radar. Would they have resolved the fuel vapour issue yet?

Where does the fuel vapour come from? How much fuel and for how long? I'll guess one would have to know what happens when a fuel tank is dropped (empty/part full/full) on any aircraft - as a general rule. Then probably it is - not much?

[swiss]

With a flat AESA antenna facing back 90 degrees to the world 0.1 sq m seems quite unlikely.

Agreed. But with probably one order of magnitude lower RCS as the Mirage 2000, 0.1-0.5 m2 seems possible.

1- a Rafale with missiles and fuel tanks is going to have an RCS over 1m^2.

Even if we assume a frontal RCS of 0.5 m2, under 1m2 is likely for the Rafale with 6 AAM and 3 EFT. Modern Droptanks have an RCS of under 0.1 sq m. And AAM's 0.01-0.001 m2. From the frontal hemisphere of course.

Nevertheless, i fully agree, the chance for a Rafale to survive an encounter with a F-35 should be very low. The APG-81 has at least 60 % more T/R Modules as the RBE2 AA. And it's very likely superior than the French Radar, technology wise. Same goes for sensor fusion.

And as Ric pointet out, the F-35 has more IR reducing measures then any 4.5 gen fighter. Plus several order of magnitude lower RCS.

[fbw]

Pirate is a dedicated IRST, considered the gold standard right now.

Legion pod is the best IRST at the moment, look at that aperture area

For one the OP was talking about integrated sensors. Two, I wouldn’t be so sure. The receivers are similar in weight 105-115 pounds for the IRST21. No exact measures on aperture area of the PIRATE. IRST21 of the legionpod is an evolved AN/AAS-42, (new processor, no literature on what was updated on receiver head compared to TigerEyes). Either way, one system was originally developed in late 80’s, the PiRATE in late 90’s. The IRST21 is LWIR, PIRATE is dual band.

LegionPod was developed as a plug and play solution for the operational need for an IRST, the entire pod weighs around 500lbs with resultant drag penalties and loss of centerline pylon flexibility (IIRC the entire PIRATE installation receiver + processor is around 180lbs)
Lastly, there is no way to definitively compare processing power,sophistication. As far as integration, LegionPod feeds target track information to mission computer and feed to cockpit display via high speed umbilical. Even with the Typhoon scoring relatively poorly in Swiss eval sensor fusion, There is a degree of fusion with other sensors on Typhoon. From EF presentation:

[eloise]

Not very far, and it's unlikely that the tanks will be dropped before AMRAAMs are on the way

If you can only track Rafale while it carry fuel tanks and launch AMRAAMS, once they drop it, you lose track and can't guide AMRAAMS anymore.
I don't think we should rely on Rafale to carry fuel tank all the time

Very likely. The Rafale has to detect the APG-81 before it can attempt to jam it.

We can't be certain that Spectra can't detect APG-81 before Rafale is detected. ESM has advantage in signal strength

[eloise]

First you're confusing IRST with an EO sensor such as the Sniper (which the EOTS and its EO functions are based on) or ATFLR or Damocles or Talios or whatever.
For example the EOTS (as well as other modern EO sensors/pods) uses very high performance MWIR sensors which allows you to look at targets thru an IR imagery which has a resolution very close to what the human eye sees (light spectrum).
Basically the principle of using the EOTS to find very long range targets like shown in the video above is like using a "normal" telescope

Many IRST have secondary EO channel, MWIR is also used by FSO and Pirate

speaking of which good luck trying to find aircraft flying around the airspace simply by looking at a telescope which otherwise in theory allows you to look at the same aircraft at very long ranges (which requires to have something that helps cueing the telescope - more on that below).

Regarding the IRST the principle is the same/similar but the sensors that most if not all IRSTs use aren't the very high performance MWIR sensors as you find on an EOTS (or on other EO sensor/pods such as ATFLIR, etc...) - they are from lower quality which should hamper detection and above all, identification range.

Moreover you're conveniently forgetting that the F-35 has in-build IR reductions measures which will drastically degrade the maximum detection range that an IRST could theoretically have against a F-35.

So and getting back to the video above, how do you think that the pilot found the windows of that building/hotel in Las Vegas with the EOTS in the first place??
- I believe that I can reply it: First it had to find the building (that contain the windows) itself, something which by itself is massively bigger and STATIC compared to a F-35! So and even before that building could have been found by the EOTS, the EOTS was (and I'm 99.99% sure of this) cued by something else in order to point the EOTS on the vicinity.
Since this was from a F-35, it was definitely thru a track feed by the sensor fusion (as you can see in a bunch of F-35 videos!) and the biggest contributors to that same track could have either been the Radar (yes, the R-A-D-A-R) and/or a pre-determined area/waypoint.

What do I mean with the above? Good luck trying to find that same building (not to mention its windows!!) using the EOTS alone...

IRST can be cued by Spectra. F-35 has IR reduction measures but we don't know how much range it can cut from IR sensor, like we don't know how much range can Spectra cut from APG-81.

So, here you are!
So can you please stop now with these "magical scenarios" where a Rafale could detect a F-35 first or about the same time at BVR range as opposed to otherwise? Thanks in advance...

I admit certain advantages of radar, but that doesn't mean IRST don't have their own advantages such as immune to jamming and more effective vs stealth aircraft.

External tanks will only be dropped in emergency situations! No External tank will be dropped lightly or just to get a somehow lower RCS - They are too expensive for that!
And then even after dropping the external fuel tanks you'll still have the pylons to "contend to" which will still contribute to increase the RCS somehow.

External tanks are cheaper than buying a new aircraft when they down. Some external tanks come with the pylon when dropped such as one on F-16 and F-22

For the "million times" (I guess):
- YES, YES and YES!

That was a rhetorical question, we don't have enough data to conclude whether APG-81 under jamming can detect Rafale first or FSO will detect F-35 at high altitude first.

[wrightwing]

If you can only track Rafale while it carry fuel tanks and launch AMRAAMS, once they drop it, you lose track and can't guide AMRAAMS anymore.
I don't think we should rely on Rafale to carry fuel tank all the time

That's not close to what I said, first of all. Secondly, there's no realistic scenario, where any Rafale/Typhoon/Gripen/F-15/16/18, would fly into combat, without external fuel tanks.

We can't be certain that Spectra can't detect APG-81 before Rafale is detected. ESM has advantage in signal strength

The odds are that the F-35 detects the Rafale and engages, before the Rafale knows what's happening, much less being able to jam the F-35 and get a BVR missile shot. That's some serious optimism, on your part.

[eloise]

Two, I wouldn’t be so sure. The receivers are similar in weight 105-115 pounds for the IRST21. No exact measures on aperture area of the PIRATE. IRST21 of the legionpod is an evolved AN/AAS-42, (new processor, no literature on what was updated on receiver head compared to TigerEyes). Either way, one system was originally developed in late 80’s, the PiRATE in late 90’s. The IRST21 is LWIR, PIRATE is dual band.
LegionPod was developed as a plug and play solution for the operational need for an IRST, the entire pod weighs around 500lbs with resultant drag penalties and loss of centerline pylon flexibility (IIRC the entire PIRATE installation receiver + processor is around 180lbs

You can compare the size of Legion pod and Pirate aperture with pilot head. From the look of it aperture of legion pod twice that of Pirate, for optical/infrared sensor, the aperture area is the most important.

Pirate.jpg (41.41 KiB) Viewed 25916 times

[eloise]

That's not close to what I said, first of all. Secondly, there's no realistic scenario, where any Rafale/Typhoon/Gripen/F-15/16/18, would fly into combat, without external fuel tanks.

Fly air defense mission close to air base, EFTs isn't a requirement, and you shouldn't expect your enemy to play to your advantage. If they can seriously threaten you by dropping fuel tanks they will try that.

The odds are that the F-35 detects the Rafale and engages, before the Rafale knows what's happening, much less being able to jam the F-35 and get a BVR missile shot. That's some serious optimism, on your part.

None of us know the sensitivity of Spectra and it is continuously being upgraded, so it is a bit too optimistic to assume it can't detect APG-81.

[nathan77]

None of us know the sensitivity of Spectra and it is continuously being upgraded, so it is a bit too optimistic to assume it can't detect APG-81.

Sensitivity or not - given the APG-81 is a LPIR radar what evidence is there that the Spectra can even reliably know it's been targeted? It's my understanding that LPIR radar emissions look like background static.

[charlielima223]

Sensitivity or not - given the APG-81 is a LPIR radar what evidence is there that the Spectra can even reliably know it's been targeted? It's my understanding that LPIR radar emissions look like background static.

Sensitivity is one thing but against radars with good LPI capabilities the RWR or EW needs to know what to look out for. Proper LPI capability from advanced AESA radars are very effective. From my understanding advanced AESA radars have LPI capability by rapidly changing their pulse iterations, frequencies, beam, and power output. Also it isn't just having an AESA radar, it is the software and hardware in it that directly correlates to how good its LPI capability is.

So I would think that it would be more accurate to say, would the Rafale's Spectra system even know its being looked at by the radar from an F-35 or F-22?

[eloise]

Sensitivity or not - given the APG-81 is a LPIR radar what evidence is there that the Spectra can even reliably know it's been targeted? It's my understanding that LPIR radar emissions look like background static.

Sensitivity is one thing but against radars with good LPI capabilities the RWR or EW needs to know what to look out for. Proper LPI capability from advanced AESA radars are very effective. From my understanding advanced AESA radars have LPI capability by rapidly changing their pulse iterations, frequencies, beam, and power output. Also it isn't just having an AESA radar, it is the software and hardware in it that directly correlates to how good its LPI capability is.

So I would think that it would be more accurate to say, would the Rafale's Spectra system even know its being looked at by the radar from an F-35 or F-22?

MQM-65 also has some LPI capabilities, but F-16 with ASQ-213 could target it and HARM could home on the signal
I am not saying MQM-65 is as hard to detect as APG-81, but HARM's seeker isn't as capable as Spectra for sure.

[optimist]

When you drop an external tank. They say you light up like a xmas tree on radar. Would they have resolved the fuel vapour issue yet?

Where does the fuel vapour come from? How much fuel and for how long? I'll guess one would have to know what happens when a fuel tank is dropped (empty/part full/full) on any aircraft - as a general rule. Then probably it is - not much?

I won't try and find it. It was a pilot. I suppose I should have said droplets. Anyway it's a big reflective target. It's not at all discrete.

[ricnunes]

IRST can be cued by Spectra. F-35 has IR reduction measures but we don't know how much range it can cut from IR sensor, like we don't know how much range can Spectra cut from APG-81.

You don't know how much range F-35 IR reduction measures can cut from IR sensor (IRST) but you assume as being a fact that:
1- Spectra can detect APG-81.
2- Spectra can jam the APG-81.
3- Spectra can geo-locate with pinpoint accuracy a F-35, or more precisely its APG-81 radar - which as opposed to a ground based radar is a target always on the move and moving very fast and changing course very often - and with that cue with also pinpoint accuracy an EO Sensor at the F-35.
4- And all of the above before the F-35 can detect the Rafale with either its APG-81 radar or with its EOTS in IRST mode.

So lets see, you put into doubt the already known FACT that the F-35 has extensive IR reduction measures which effectively means that the enemy IRST will detect it a shorter ranges compared to aircraft with much less comprehensive if any IR reduction measures which is the case of the Rafale but then you assume that all the 4 points above - which no-one knows including yourself, if they are true (and probably aren't) - can be attained operationally! Priceless....

External tanks are cheaper than buying a new aircraft when they down. Some external tanks come with the pylon when dropped such as one on F-16 and F-22

Hence why they are dropped in EMERGENCY situations. Reducing the aircraft's RCS from 1 m2 to 0.8 m2 or so is NOT AN EMERGENCY situation, capiche?

(having been shot with a missile is!)

That was a rhetorical question, we don't have enough data to conclude whether APG-81 under jamming can detect Rafale first or FSO will detect F-35 at high altitude first.

I'll tell you what "not enough data" you actually have (or don't have, to be more precise):
1- You don't have enough data to conclude that Spectra can detect APG-81.
2- You don't have enough data to conclude that Spectra can effectively jam the APG-81.
3- You don't have enough data to conclude that Spectra can geo-locate with pinpoint accuracy a F-35, or more precisely its APG-81 radar and with that cue with also pinpoint accuracy an EO Sensor at the F-35.
4- And you certainly don't have enough data to conclude that a Rafale will be able to detect a F-35 with its APG-81 radar being jammed first (and supposing that the Rafale can jam the APG-81) than the opposite.

As opposed to the above it's already well known the huge diference and advantage that a Stealth aircraft has over non-stealth aircraft like the Rafale, SH, etc..., we know that Stealth is here to stay and we also know that IRST are not even the main mean of long range detection for any fighter aircraft in existence! IRSTs are a complement to Radars (and other sensors). And they (IRST) have been around at least since the late 1950's so their capabilities (and limitations) are well known.

To conclude and since you like scenarios, I'll give you a couple of scenarios:
- The F-35 ESM (AN/ASQ-239) geo-locates the Rafale's RBE2 radar (while the F-35 has its APG-81 radar turned off) and cues the EOTS to the Rafale and then cues an AMRAAM and BAM! Rafale dead!
Or another:
- Both the F-35 and the Rafale have their radars turned off but since the F-35 has in-built and extensive IR-Reduction measures the F-35 IRST will detect the Rafale first than the Rafale IRST will be able to detect the F-35. AMRAAM cued, BAM! Rafale dead!
How's that for a scenario?? Happy now??

What I find puzzling and at the same time amusing is that when people (like yourself) devise these "anti-F-35 tactics" forget that the F-35 will also be able to use those same tactics AND MUCH MORE EFFECTIVELY so.

So please, and I'm asking you again please, can we now stop with these "magical scenarios"?? Again, thanks in advance...

[sprstdlyscottsmn]

Looking at the AESACalc sheet and the assumptions (there are always assumptions) that I am using for the APG-81 I see a 1m^2 detection at 133nm with wide area search, tracking at 104nm. With that refueling probe it seems folly to assume the Rafale is 0.1 clean. I can't see less than 0.5 myself. For the sake of discussion we will go with 0.1 just to be pessimistic. I see 6 aams (MICA is very finny, unsure how Meteor intakes look RCS wise), one tank, and three LO pylons as being 0.41m^2. This has a tracking range of 83.7nm with no jamming. I will agree that Spectra is the best EW system outside the US. I do not think it is up to par with the Barracuda. Anti AESA EW equipment needs AESA level tech. The RBE-AA is not as advanced as the APG-81, so there is no reason to assume that Spectra is. If I assume that Spectra can even detect the APG-81 it's jamming capability will be minimal. For the purpose of the radar sheet I will call it an increase of receive noise of 20dB. This moves the tracking range to 28nm/52km. Even if OSF is cued by Spectra, this is far beyond any stated laser rangefinder for OSF. Without range info you can't launch. So, even giving the Rafale every advantage I can, it is still going to be engaged by AIM-120D outside passive targeting range.

Then there is the issue that Meteor needs a radar track to guide. Want to know the range at which a meteor can track an F-35 (0.0005m^2)? If I model it as a PESA with a 10x10 element with 5W power per element (it an MSA not a PESA afterall) then it "might" track at 2.3nm per the sheet. Oops, Barracuda vs MSA radar. Let's add 45dB noise to the receiver. 0.3nm. Meteor is not going to be successful against an F-35.

"Well what about spectra vs the AMRAAM? It's a MSA too!" Okay. Lets make the same seeker assumptions for both missiles. No Jamming? 8.3nm. Add 35dB noise (Spectra isn't Barracuda afterall)? 1.7nm. Oops, AMRAAM-D has 2-way datalink to the APG-81. Let's cut the jamming effect in half. 17dB noise. 3.8nm.