Just a question, are L-band radars mounted on a fight jet big enough to detect something like the B-2 in useful range?

Dunno. But I think that is what they are aimed at…

X-band: 2.5-4 cm
L-band: 15-30 cm

Thales are supposed to be *claiming* that their SMART-L (an L-band radar) is capable of defeating current LO measures… that claim is over 6 years old now.

I see power figures (for a Flanker) of around 5kW banded about the ‘net. Not sure where those have come from though.

edit: The APG-77 on the F-22 is supposedly capable of about 20kW power output.

Additionally, the RCS of any aircraft is supposed to increase with the inverse square of the frequency of the radar targeting it.

The following is an extract from “Radar Cross Section” by E.F. Knott, J.F. Schaeffer & M.T. Tuley

Assume for example, a target shaped for low RCS having a -20 dBsm cross section at 10GHz. The RCS at 1.25GHz using a lambha^2 dependency would be -2 dBsm. For that case the surveillance radar would have a 283km (153 nm) detection range. On the other hand, the AI radar with pulse compression would be reduced to a 24km (13nm) detection range, and the missile to 11km (6nm). The disparity becomes even more apparent for wider spreads in radar frequency. For instance, if a UHF surveillance radar is postulated, instead of the L band system, the detection range should equal or exceed the preceding 283km figure, depending on exact system parameter assumed. However, it would be unlikely in that case that the surveillance radar would have sufficient resolution to vector an interceptor sufficiently accurately so that hand-off to the AI radar could be accomplished

Unfortunately, I am very unsure about whether they have kept the radar power output constant for that example.

According to the equations, range drops with the quadratic root of power (i.e. to double range, you need to increase power by 16x), and RCS rises with the square of frequency.

So the theoretical 5kW L-band radar has a 1.4x reduced range due to its 1/4 power output of the APG-77, but it is dealing with maybe 18 dBsm better return at the target – that is a reflectivity increase of about 70!

[Note, that doesn’t work out at 50x better performance!!! For instance, the APG-77 will have 2x the radar power at the target of the L-band, since the signal strength attenuates on the way back too]

Its not so simple. Its not what Lockheed martin and partners give to the Services , its what the services ask from the vendors.

Indeed.

Given the requirements that were placed on it, the F-35 is an absolutely fabulous aircraft. I would doubt anyone on here truly comprehends just how bright some of the folks that are working at Lockheed are (and that would include me – even though I *should* have a fair idea!).

However, I think the DoD firmly screwed the pooch by insisting on STOVL capabilities. That insistence I feel has fooked the whole program up; too many serious compromises have been made to accommodate the STOVL architecture.

No doubt the electronics on board will be world class, but, same as I feel with the Super Hornet, you cannot hide behind just electronics. I have serious doubts about the F-35’s LO signature at angles away from the LM PR head on figures, and I have very serious doubts the dynamic performance of the airframe is good enough to get it out of trouble if its electronic shield fails it.

I think this 5 radar claim is overhyped and not logical..

I believe it is very logical.

Consider if the PAK-FA was intended to also eventually replace the MiG-31.

Would it not be of considerable benefit to be able to operate independent of GCI and be able to vector yourself onto, say, a B-2 from a considerable distance out*? Isn’t the next-gen USAF bomber also supposed to be subsonic? Could make for a risky penetration.

You don’t need precise information, that will come as you close the gap and the conventional X-band radar return gains in strength or optical instruments localise the target for engagement.

*tradeoff obviously being emitter power of an L-band vs. return from a LO target from the higher power X-band… swings and roundabouts.

How effective are these sytems in a heavy ECM environment, and with bombs coming from different angles/azimuths?

You’ll be doing very well to jam within 5 miles of the radar. Oh, and the bombs from one aircraft cannot come in from many different approaches as you need to saturate the target, so don’t have time to do separate launches.

I think the M.3 speed estimate is VERY conservative, especially if the SDB is launched supersonically. There’s no way it could achieve the ranges it does, if it bled airspeed like that. My guess is that it’d be flying at 2-3x that speed, and coming in at a very steep angle.

Seriously. You are trying to say the SDB operates in the transonic regime.

Lets keep it sensible, eh? Mach 0.5 at best I would imagine, unless there is terminal maneuvering software.

Oh, and the thing will have to be launched at maximum range to keep the launch aircraft far enough from the S-300/400.

If the SDB is launched from 60kft and 50 miles away, thats a glide angle of around 12.5 degrees.

I’m not arguing about theoretical top speeds.

I am only using top speed to highlight the fact the F-16 has a much lower drag polar than the F-35.

Unsurprisingly, you fail to realise the implications of that with respect acceleration.

You will now probably continue to waffle on about the military thrust advantage of the F-35, again not realising the F-16 is actually faster (both in acceleration and v-max) when it counts.

A combat loaded F-16 can’t hope to keep up with F-35s though

Yes it can.

When it counts, an F-16 can and will out-accelerate an F-35.

(I.e. an F-16 is only faster when unarmed, and without external fuel, or to put it more simply- a clean F-16 is only slightly faster than a combat loaded F-35).

Not true.

An F-16 with 4 AAMs will have a better T/D an F-35. An F-16 with 6 AAMs may have a better T/D an F-35.

An F-16 with drop tanks will not out accelerate an F-35. An F-16 will always jettison their drop tanks when dogfighting.

Do you not see the fallacy of your argument?

Do you understand the implications of higher T/D ratios?

Even F-15s which ARE faster than F-16s, haven’t gotten above M1.4 in combat.

Indeed, if you try turning at such high speed the OpFor will turn inside you at a much lower speed and whack you with an IR missile.

The F-15s would also have very limited elevator authority at such supersonic speeds.

The F-35 is designed to be able to fly its max speed WITH a full internal load.

Don’t equate “max speed” with combat speeds.

The two are nothing alike, and it would be ignorant to suggest such.

I take it you didn’t bother looking at that P&W link, or take into account installed vs uninstalled thrust, altitudes, etc…

Do you try and teach your father how to have children too?

I take it from your overly confidant tone that you can provide solid information that it will be a distributed system, distributed meaning it will have sensors all around the aircraft providing a spherical or near spherical coverage like the F-35’s EO DAS does. If you can’t then you have no right to claim others are making assumptions, for obvious reasons.

Considering the Russians have long since had distributed radar systems on the Flankers, I find the “leap” to distributed MAWS not very large.

If the F-16s are using afterburners to keep up, what do you suppose would happen once the F-35 goes to afterburner as well? The F-16 gets a ~12k lb increase in afterburner(and it’s already struggling to keep up). The F-35 gets a 16-23+k lb increase in full afterburner.
Now mind you, these are all static, uninstalled numbers, which further blurs things, as we don’t know the installed figures, or at which altitudes the respective motors will perform most advantageously.

Arrghh. Its like trying to explain things to a 5 year old.

The F-16 has 58.7% of its total (afterburning) thrust available in military power only.

The F-35 has 67.0% of its total thrust available in military power only.

Do you think the F-35 has a higher top speed than an F-16? I have yet to see anywhere claim the F-35 can get above Mach 1.8, much less beat a Viper. Now, seeing as that is the case – do you not realise what that implies for drag characteristics?

Work the proportions. Its not complicated.

The F-35 can avoid the dogfight in the first place, and if forced to merge, will be able to tangle with an enemey fighter without getting mission killed(I.e. dropping ordinance before striking the intended target.)

Ahh, back to that old chestnut are we?

1. The F-35 will not be able to avoid the dogfight. Long wavelength radar will localise the F-35 enough to allow vectoring of OpFor air assets to the area.

2. Assuming a 2025 environment (i.e. Gen 4+), these assets will acquire the F-35 using IR means, if not by AESA means.

3. They will be able to dictate the nature of the fight by being able to start their missile launches from a higher energy state (due to the F-35s tardy top speed).

4. They have more missiles for greater combat persistence, so can ripple fire if needs be (Unless you want to sacrifice that precious “stealth”?).

5. Upon the merge, the F-35 will not only be mission killed, it will be actually killed due to its comparative lack of maneuverability.

The only way F-35s can survive is if they are guarded by F-22s and or electronic jammers the whole way in. Which mostly defeats the purpose of them in the first place. Or the Opfor are hopelessly outdated (i.e. Serbia).