PPRuNe Forums - View Single Post - F-35 Cancelled, then what ?
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Old 10th Jul 2015, 15:43
  #6706 (permalink)  
KenV
 
Join Date: Aug 2014
Location: New Braunfels, TX
Age: 66
Posts: 1,954
Oh dear

https://medium.com/war-is-boring/no-...r-5508913252dd

Two dozen Chinese J-11 fighters brought nearly 250 long-range missiles to the mock fight. The same number of F-35s carried fewer than 100 AIM-120s. Beijing’s jets easily overwhelmed the Americans.
Oh dear indeed. From the cited blog:

In any air-to-air duel, the pilot who spots his target first and shoots first is, nine times out of 10, the victor.
Dead on.

To this end, the F-35 does have a high-tech radar, high-fidelity cameras and other advanced gear that can detect airplanes. But foremost, Lockheed optimized these sensors for spotting targets on the ground — and at relatively short distances. The F-35 can see great. It just can’t see all that great into the air. At least not compared to modern Chinese- and Russian-made jets — the planes the F-35 is most likely to face in battle in some future war.
An absolute crock!! F-35's AAQ-37 DAS has successfully tracked ballistic missiles. As has the F-35's APG-81 radar. And incidentally, the APG-81 is a direct descendant of the APG-77 in the F-22 Raptor and retains ALL of the APG-77s superlative air-to-air capabilities while improving on them and adding air-to-ground capability. OK, the author of the article is ill-informed, but you guys citing him claim to be knowledgeable about air-to-air combat. Surely you guys know this obvious truth about the APG-81 radar. But if so, why on earth would you cite this grossly ill-informed article?!!

While the specific details remain secret, Kopp estimates the APG-81 can detect an aircraft with a radar cross-section of three square meters—a MiG-29, for example—just over 100 miles away. Russian radar-maker Tikhomirov claims the Su-35’s Irbis-E can spot a similar-size target at greater than twice that distance.
Hilarious. Even assuming this "estimate" vs this "claim" is accurate (a HUGE assumption), the F-35s radar cross section is a tiny fraction of the MiG-29's "three square meters", with the J-11 being significantly larger than the MiG-29!

But wait, it gets better. The missiles have terminal radar guidance. How well will a radar guided missile do against a stealth target vs a non stealth target? So even if thru some miracle the J-11s radar detects the F-35s first, how will their missiles lock onto their targets? "Oh dear".

OK, the author of the article is ill-informed, but you surely you air-to-air knowledgeable folks are aware of the radar equation, which states power at the receiver is a directly proportional to radar cross section and inversely proportional to the square of the range, times 2! In short, radar cross section is a HUGE deal in radar detection, radar tracking, radar intercepts, and radar terminal homing. But if you do know this, why on earth would you cite this grossly ill-informed article?!!

But it’s possible radar range is irrelevant. In an aerial battle between stealthy jets — with each side trying to stay undetected as long as possible — it’s likely that none of the opposing pilots would even want to activate their radars at all. That’s because most fighters carry gear that can sense radar waves and pinpoint their origins.

Instead, modern planes in a high-tech war would probably rely on their undetectable, “passive” infrared sensors to locate each other in the air.
Really? "Would probably" not use radar? The author of this article failed to include that the F-35's APG-81 radar has all of the APG-77's LOD (low probability of detection) and LOI (Low probability of intercept) characteristics. Meaning the F-35 pilot can leave his radar on and remain pretty damn stealthy. In addition, the F-35's stealthy MADL datalink means the F-35s will be linked together into a network. Meaning they can share sensor data in real time and effectively enlarge the effective aperture of their individual sensors. And (what a coincidence!) sensor range is directly proportional to aperture size. "Oh dear" indeed.

But let's assume the F-35 pilots are all stupid or very poorly trained and don't take advantage of their superior radar, nor network their radars, and instead turn their radar off and rely solely on passive sensors.

The F-35 has a damn sophisticated passive RF system that can detect the Russian built radar emissions at more than twice the range the radars can detect targets (that pesky radar equation raises its ugly head again.) So things get even better (or worse, depending on who's side you're one. Our local "experts" seem to be on the side of the Chinese and Russians.) when using passive RF sensors. Because the F-35s are networked, this enables them to use their passive sensors to compute a highly precise 3D location of the emitter(s), and not just a bearing to them. Precise enough to provide launch guidance to their radar guided missiles. That means the F-35s can use just their passive RF sensors to launch their radar guided missiles. "Oh dear."

What happens if the opposition stops emitting RF? Great. Let's look at IR.

But take a look at the F-35’s engine nozzle. It’s round. Highly stealthy planes such as America’s B-2 bomber and F-22 fighter both boast flat engine nozzles that spread out their exhaust plumes, cutting back on the telltale IR signature.
Hilarious. The Chinese/Russian engines nozzles are......wait for it....round also! "Oh dear!"

The F-35 has an IR detector (actually it has 6 to provide full spherical coverage around the F-35) that can track a ballistic missile at considerable range. But let's ignore that and assume both sides' IR sensors are equally sensitive. The F-35's sensors are networked, effectively increasing their aperture size, and thus their detection range. "Oh dear!" And that networking gives them a passive 3D picture precise enough to provide targeting data for radar guided missiles. A picture all fused together on their helmet displays. The F-35 can launch a radar guided missile with their aircraft radar turned off and guide them to the target area where the missile switches on its own radar. "Oh dear!" The J-11 is limited to a short range IR missile with it's aircraft radar shut down. "Oh dear!"

And since this discussion is all about long range air-to-air, what matters here is forward aspect IR signature. And the F-35s forward aspect IR signature is even lower than the F-22's, never mind the J-11's So in a long range engagement (which is what this discussion is all about) the F-35's IR emissions are far below their target's emissions. "Oh dear!" And their IR sensors are fused and networked. Oh dear.

There's plenty more (like the F-35s built-in RF jamming capability), but this will suffice. Perhaps it would be wise to peruse web sites with just a modicum of veracity and that don't have an axe to grind.
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