There has never been exactly clear cut information of the performance of the Chinese 3rd generation missiles (TY-90, Pl-9C, Pl-8B, possibly Pl-5E?), so I decided to take a look into electro-optical guidance and the data I could gather on Chinese missiles. Luckily, the 3rd generation Chinese missiles are quite simple and are standardized across the board with the only exception seemingly being the Pl-5E.
- Pl-5E, let’s start with the odd ball here, and also the one I have the least information on. This is an improved Pl-5B, according to the book I am using the Pl-5C does not exist and the missiles progression is Pl-5B → Pl-5E. This missile incorporates improvements from the Pl-9 program but does not offer any increased flare resistance, it should be on ~par with an Aim-9L. The only hint to possible improvement is “重新设计了双光 路红外近炸引信” but all the translators I run this through say it is talking about the proxy fuse being ‘dual-optical’ . The reason I mention this is incase somebody has a better translation of it since their is a chance they are trying to say the seeker is dual wavelength (IR/UV) AND has an improved proxy fuse (an issue during the Pl-5 development). Below is the untranslated page for the Pl-5E:
- .1 Pl-5EII, less information is known on this newer modernization of the Pl-5. This is primarily a seeker upgrade; the exact seeker configuration is a bit unclear due to translating, but it appears to use a Dual Band Seeker and not the Cross Linear Array Tracker method used in the other 3rd generation missiles. The Dual Bands used are a bit different than traditionally, it appears they are using 2 wavelengths in the infrared spectrum instead of grabbing one from the UV, therefore the design is very close to what is shown in my Dual Band discussion below. In terms of performance, it can only be defeated by Pyrophoric Decoys or DIRCM. Oddly though, on the display model they call it a ‘multi-element’ which the Chinese have typically used to describe the Cross Linear Array Tracker seekers; I suspect they still describe it as multi-element because the missile still uses multiple elements, 2, except with different seeker materials instead of a pattern of same material seekers.
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.2 Pl-5DE, no concrete information on this missile, couldn’t even find the general missile data on the display model nor a brief datasheet on it. Only could find unreliable information claiming it uses a Dual Band Seeker with IR/UV configuration instead of the 5EII’s IR/IR configuration. Flare rejection differences should be almost identical to the 5EII with very minor improvements.
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The Pl-9 is technically the first Chinese 3rd generation missile. The first versions, Pl-9, were on par with a Python-3/Pl-8/Aim-9L with no real flare rejection process. It wasn’t until the Pl-9C that CCM was adopted. The method used in the Pl-9C is Cross Linear Array Tracker using a quarternary cross shaped elements. In addition to the seeker element design, an onboard computer using DSP algorithms are able to filter out decoys and even create a rough 2D image of what the seeker is seeing. This is comparable to FIM-92D/E and only slightly worse than a Dual Band Seeker; I will explain below the differences:
Cross Linear Array Tracker: It operates in a conical scan with the secondary mirror offset so the focused beam does not lie in the center of the seeker element but instead rotates around the elements. The typical shape used is a cross shape using 4 elements. When an IR signature is detected and the beam hits an element, it will create a signal return and a magnitude of return. Depending on where the true target is, as low as 1 return can happen per cycle which the guidance computer will be able to compute the estimated real target position and move the servos so the missile heads towards it, where more returns should happen. A max of 4 returns per cycle can happen, flares and thermal jamming will change the magnitude of the returns. However, the cleverness in this design is that most of the time the seeker is not actively scanning, since it only is considered scanning when the beam hits 1 of the elements. Therefore the only ways to defeat this seeker is a continuous flare dump so that it will constantly see flares multiple times per cycle and changes the bias OR using DIRCM to blind/fry the seeker.
Dual Band Seeker: This is also a very hard to spoof method. The seeker has two elements with one being placed in the secondary mirror assembly. A reticle bandwidth filter is placed between the secondary mirror and the other element. This reflects the bandwidth for the first element but lets the second element seeker pass thru. The spinning reticle is like the previous designs used in the Aim-9L as a means to reduce how often the seeker is actually scanning by limiting how often it ‘sees’. This method works so well because flares typically have a different energy ratio along the wavelength emission curve. While the seeker only sees 2 points of this curve, it can compare the estimated temperature values of the target and the flare. If the original target has a ratio of 3:1 and a new object detected is 5:1, the missile will know that this is a decoy and will be filtered out. The way to defeat this missile is by using Pyrophoric decoys with the same or very similar spectral match to the aircraft. DIRCM should still work on this type of missile since it is not directing the laser away from the imaging sensors and will still get fried.
- Pl-9C, as mentioned earlier, this missile uses the Cross Linear Array Tracker method and uses 4 elements and a digital signal processor with the ability to have different algorithms uploaded to enhance performance down the line. What this means is at the very least it can effectively detect signal scanned flares and filter them out as the return signal does not match the previous return signal on that element nor the return signal from the other elements. At the best case, they could use the return data to construct a basic 2D image similar to the FIM-92 does and will be able to reference this image and filter out flares as their center will appear off from the targets axis and will be dimmer do to very low occurrence rates. Best case scenario would make the missile virtually unflarable and requiring constant perfect timing of flare drops sync’d with element scan time, which is not currently possible.
- Pl-8B and TY-90. Both of these missiles actually use the same exact methods as the Pl-9C, actually taking what was developed from it and integrating it into them. The algorithm used between these missiles may or may not be the same, most likely with minor differences.
As to how this relates to in-game performance, Pl-5C seems to be the Pl-5E, just named incorrectly and appears to work accurately. Same with the Pl-8. As for the TY-90, I am skeptical that this missile is underperforming after it’s shadow nerfs and I’ve seen it get flared by a handful of flare drops and not entire flare dumps. Additionally I would like to test it against thermal jammers like the Su-25T uses to make sure it is not effected by it.
If anyone is interested in helping me test the missile and validate its performance, please DM me or reply to the post so we can work out a time to try this out.
*Note: DIRCM is a newer concept and only the IRIS-T is known to have DIRCCM; possibly the Pl-10 but there isn’t enough information to make that determination. R-73M, Aim-9X, ASRAAM, etc do not appear to have any DIRCCM, which requires a method of diverting the laser away from the imaging sensors. I should also point out DIRCM is over-performing in game, it increases the probability of missing, only activates AFTER a missile launch has been detected, and can fry the missile if powerful enough/given enough time. Here is what DIRCM looks like, note how a return is still generated with an epicenter:
