F-16s for Ukraine

[eloise]

Assuming a 2 degree beam width, the AWG-9 1-bar is a 20x2 scan or 10x1 beams, and is ALSO not very useful unless you are told the general bearing and Altitude of the target. The Irbis-E 10x10 is then 5x5 beams and as such has even less dwell time than the AWG-9 figure shown. Having a 10x10 vs the 20x2 means you are less sensitive to needing to know the altitude but need much more accuracy on the bearing.

Since the AWG-9 and Irbis-E radars have nearly identical aperture sizes (0.91 m vs. 0.9 m), and if assuming they operate at the same frequency, their beamwidths should be approximately the same - around 2.3-2.5 degrees.
The cued search mode of the Irbis-E covers a volume of 100 square degrees, which could correspond to different scan patterns. For example:
A 10° × 10° sector for close-range targets, providing a balanced horizontal and vertical coverage.
A 40° × 2.5° sector for long-range targets, where vertical angular variation is minimal, allowing a wider horizontal search
Either way, a 10 degree cued is well within capability of the RWR. You can increase dwell time by spend more time on volume search. If we assume the Dwell time per beam position to be 0.03 seconds similar as Zaslon , it will completes the scan of that 100 square degree degrees search area in 0.55 seconds

RWR might give that info, but I assure you the Su-35s RWR is going to have a harder time picking up the 2-3kW APG-66 compared to the F-16s RWR trying to pick up the 20kW Irbis-E.

Not necessary true, Irbis-e is an electronic scanned array, which mean it has various weighting mechanism to reduce the power of the side lobes significantly, whereas APG-66 is a mechanical slotted array radar with predictable scan pattern and much higher sidelobe/main lobe ratio. It should be easier for RWR system to detect and classify a mechanical scan slotted array

[hornetfinn]

RWR might give that info, but I assure you the Su-35s RWR is going to have a harder time picking up the 2-3kW APG-66 compared to the F-16s RWR trying to pick up the 20kW Irbis-E.

Not necessary true, Irbis-e is an electronic scanned array, which mean it has various weighting mechanism to reduce the power of the side lobes significantly, whereas APG-66 is a mechanical slotted array radar with predictable scan pattern and much higher sidelobe/main lobe ratio. It should be easier for RWR system to detect and classify a mechanical scan slotted array

I don't think that Irbis-E necessarily or even likely has much higher sidelobe/main lode ratio. APG-66 has Slotted Waveguide Planar Array antenna, which is pretty good in this regard and not far away from PESA antennas. Of course a lot depends on quality of components, manufacturing tolerances and also scan angle in the case of PESA radar. But better MSA antennas can have equal sidelobe levels to most PESA antennas, especially with usual pherrite phase shifters used in small PESA radars (like in fighters).

Otherwise PESA do have advantages especially with the unpredictable scan pattern and better ability to control the waveform. I'd bet they are very roughly in the same ballpark overall when it comes to detectability by RWR/ESM systems. Of course it then depends on which aircraft has better RWR system...

[eloise]

No escape zone for R-37 against Mig-29 would be ~250km under the condition that Mig-29 MAWS pick up the launch of R-37 the first second after it was fired.
In reality, I doubt Mig-29 are that good, thus NEZ would be higher than 250km.

R-37 launched from Mig-31 can fly 400 km, however, Mig-31 can cruise at 68kft, Mach 2.5 (which is basically at the center of its envelop). I would expect Su-35S loaded with R-37 to cruise at 40kft, Mach 0.85
So the kinematic range of R-37 launched from Su-35 will be a lot shorter compared to R-37 launched from Mig-31, likely 250 km or less. The NEZ probably something like 90-100 km.

[darkmount]

R-37 launched from Mig-31 can fly 400 km, however, Mig-31 can cruise at 68kft, Mach 2.5 (which is basically at the center of its envelop). I would expect Su-35S loaded with R-37 to cruise at 40kft, Mach 0.85
So the kinematic range of R-37 launched from Su-35 will be a lot shorter compared to R-37 launched from Mig-31, likely 250 km or less. The NEZ probably something like 90-100 km.

That's very interesting, but I don't think carrying R-37 would degrade Su-35 speed so significantly.

Maybe if it was carrying four R-37, but maybe that Su-35 which shot down a Mig-29 from 217km was only carrying one R-37.

[sprstdlyscottsmn]

That's very interesting, but I don't think carrying R-37 would degrade Su-35 speed so significantly.

Maybe if it was carrying four R-37, but maybe that Su-35 which shot down a Mig-29 from 217km was only carrying one R-37.

Eloise was listing cruise speeds, not max speeds. I do not expect you would find one wing mounted R-37, they would be carried in pairs

[darkmount]

That's very interesting, but I don't think carrying R-37 would degrade Su-35 speed so significantly.

Maybe if it was carrying four R-37, but maybe that Su-35 which shot down a Mig-29 from 217km was only carrying one R-37.

Eloise was listing cruise speeds, not max speeds. I do not expect you would find one wing mounted R-37, they would be carried in pairs

Su-35 can accelerate before firing, and maybe no Su-35 will carry a single R-37, but perhaps that particular Su-35 was carrying a pair of R-37, and it fired the first and only one was left before it shot down the Ukrainian Mig-29.

[eloise]

Su-35 can accelerate before firing, and maybe no Su-35 will carry a single R-37, but perhaps that particular Su-35 was carrying a pair of R-37, and it fired the first and only one was left before it shot down the Ukrainian Mig-29.

Still, Su-35 can't go as high or as fast as Mig-31 so its R-37 won't go as far

[darkmount]

Su-35 can accelerate before firing, and maybe no Su-35 will carry a single R-37, but perhaps that particular Su-35 was carrying a pair of R-37, and it fired the first and only one was left before it shot down the Ukrainian Mig-29.

Still, Su-35 can't go as high or as fast as Mig-31 so its R-37 won't go as far

So the 400km range figure is only achievable when firing from Mig-31? Is this based on calculations, or was it revealed by the Russians?

Btw imagine the potential of AIM-174 with something very fast and very high altitude like F-15.

If the main pylons can carry up to 5000lb then they can carry two AIM-174 with boosters.

[sprstdlyscottsmn]

So the 400km range figure is only achievable when firing from Mig-31? Is this based on calculations, or was it revealed by the Russians?

The 400km figure predates R-37 being cleared for ANYTHING other than the MiG-31, and the entire point of the MiG-31 is operating at 2.35M at ~60,000ft. That is it's design point. So, yeah, the 400km range figure is for a 2.35M 60,000ft shot.

[sprstdlyscottsmn]

To understand the MiG-31 lets compare the F-22

Subsonic combat Radius
MiG-31_780nm
F-22____595nm

Supersonic Radius
MiG-31_390nm at 2.35M for duration
F-22____460nm for 100nm supercruise.

MiG-31 retains 50% radius when entire mission flown above Mach 2 and 60,000ft
F-22, doing the math, would only retain 43% of it's range if the entire mission was flown above 1.5M and 50,000ft.

The MiG-31 was purpose built for this, to the exclusion of all else. 5G, no bubble canopy, no AoA capability, huge RCS. It is NOT a good fighter or multi-role aircraft, it IS the most potent supersonic missile boat ever put into service.

[darkmount]

To understand the MiG-31 lets compare the F-22.

[...]

OK now that makes sense, so thanks for explaining.

[Lieven]

Belgium won’t send F-16s to Ukraine in 2025 despite a previous pledge. Ukraine requested a pause in deliveries due to pilot shortages. Meanwhile, Belgium retains old F-16s for spare parts as its own fleet transitions to F-35s.

See the news article on F-16.net: https://www.f-16.net/f-16-news-article5311.html