Everytime I see a Ka-31, I am reminded of this game.

In the game Command and Conquer Generals Zero Hour, with the China Generals you can get the Helix unit, which is one of those Kamov Ka-28/31s. The neat thing is that you can get them upgraded with a turret of twin rapid firing cannons on the nose, and they can tear apart anything on the ground. Or get Bunker upgrade, then put five China rocket wielding infantry (rocketmen) to create a flying bunker, so the whole unit fires a lot of missiles at anything on the ground.

“Now question on the MMR, it operates on the X band, the Gripen radar operates on the S band, what is the main difference and advantages/disadvantages, and does the LCA MMR only operate on the X band or both X and S?”

I would be quite surprised if the Gripen radar uses S band only.

Advantage to using S band—

Longer range. Longer wavelength travels much farther in the distance while losing/reflecting less energy through the atmosphere. Long wavelengths are very good for search radars. Better range, covers more volume.

Ability to detect LO threats. Stealth tends to be optimized for the X-band, not the longer wavelength.

Disadvantage of S-band. Its quite poor for tracking use, since longer wavelengths lack enough resolution for a precise ranging and location of the target. Tracking radars prefer to use higher bands like X or K.

Gripen cannot use S-band alone, especially since I have seen very highly resolved SAR images by that plane. It still should have X or the even shorter K bands. I say, it probably has K given those SAR images.

MKI BARS is said to have dual spectrum, one low band, which I think is C band, and the usual X band. Dunno about MMR.

Once again, longer wavelength bands means more search volume and range.

Shorter wavelength bands means greater tracking precision.

You can figure out here why SAM systems often have seperate search and tracking (also known as fire control) radars.

A combat aircraft that’s fully in service should have every single line of FCS algorithm verified and validated. Otherwise, the aircraft simply cannot be accepted by the airforce.

Algorithmic cross checking is a reason for having quad digi FCS but in combat aircraft, survivability is more important.

Nearly the same scenario for passenger liners. It’s not algorithms that worry the operator of a large body. It’s the possibility of FCS failure due to a catastrophic event or an incident which puts the FCS in jeopardy.

I can’t recall any aircraft (combat or civilian) that’s already in service that encountered an algorithmic incident with their FCS that resulted in fatality. That doesn’t mean that it hasn’t occured, just means that I couldn’t find it. That says something about its rarety. Again for in service aircraft, survivability is the greatest feature a redundant FCS brings.

I am even willing to wager that if 3 of the 4 digi channels are turned off in an in service combat plane, that one remain digi channel would still be able to achieve 100% of the aircraft’s flight regime. Where as, in a 3D +1A system, if the 3D channels were to be turned off, the aircraft would be considered combat ineffective.

The very reason for quadruplex system is algorhythmic redundancy. It is not hardware redundancy.

The FCS control wires running throughout the aircraft are the same and shared by all four modules. They have no extra set of wires or anything. Those wires are likely to be damaged in combat compared to the computers. It does not matter how many computers you have, if those cables are cut, everything is lost regardless if you have one computer or 10. If your power supply is cut, everything is lost regardless if you have one computer or 10.

Multiple modules do fix the problem of processor crashes (each module has their MBTF), and bugs (code error or algorhythmic failure). But they are designed differently for each for a primary reason.

If hardware protection is the issue, then you should have two or more parallel FCS, and that would not be called quadruplex. It would not be called redundant; it would be called backup. And if you want a backup, the best backup is always a purely mechanical system.

As Castor said, and I have said before, modules are made with different processor architectures, programmed by different programming teams from different cities, studied from different schools, verified never to meet each other, even using different programming languages for each. You don’t need to go as extreme as this, but each digital module must be programmed different (each module by a clean room programming team at least) and the reason is achieve algorhythmic diversity, not hardware backup. And nothing can be more diversified than to add an analog module to the mix.

Actually I think the LCA nose is not painted correctly or the actual nose may be longer. That’s the LCA tech demonstrator you are looking. It does not have radar, just telemetric equipment. The actual bulkhead line is more ahead than what the LCA pic above goes, about a meter and a half ahead of the cockpit bulkhead. This is where the components are rested. Since the radar antenna is more further out, that should be where the actual radome would begin. It would not be MiG-29 sized, certainly not. It takes a real big plane to hold a MiG-29 sized radar. The radar should be Kopyo sized, which should also be the size of the Gripen’s radar. This is especially since the Gripen and the LCA belongs to the same size class.

Look at the picture of the MMR again. The ring nearest the antenna represents where the nose bulkhead should be. The ring on the back represents where the cockpit bulkhead should be. Tell me how you can fit that on the picture of the plane above.

Since it’s just the tech demonstrator, I’ll give it the benefit of a doubt that the prototypes with the actual radar might have a different nose than the demonstrator.

what does the rafale and M2K-5 use ? the M2K is supposed to have a very good FBW system and supposedly the first a/c that went without a crash in its test pgm.

It’s also a conventional delta, which is a less risky venture than deltas with active canards. Deltas with active canards are said to be highly unstable—almost every venture on this seems to have some crash one way or another.

Every design has a reason why they chose this FBW layout and why another chose this FBW layout. It does not make one plane superior over another by FBW alone. FBW are like shoes—its there only to fit.

No, the 4th flying prototype (the fifth in total) will have Chinese equipment—HUD, avionics, and radar. I don’t know when it will fly with Grifo—RC400 is a far shot, and appears more intended for the Chinese market than Pakistan’s. The RC400 issue is closely related to the EU’s call to lift the arms embargo to China, and that is not likely now due to the pressure from the Bush administration. But if they did go through, China will politically reward the EU by buying a lot of stuff (even if China does not need them or will do it in the detriment of its local defense industry), and I bet that will include fighter radars from France or Italy for the FC-1 and even the J-10 (Grifo was said to be eyeing the J-10 market, and is said to even have a Grifo version for the J-8II). Its a far shot and it won’t likely to happen, so China appears going back to its more logical and cost effective plan of using their own radars and fire control systems on their FC-1. Its easier to integrate domestic missiles like the SD-10 with their own radar.

I think there is an issue with the SD-10 integration as the Chinese may not be willing to give the launch codes and the software (classified data) of their latest AAM to a European company that is in NATO. I think China wants to sell a packaged deal—both radar and SD-10 must come in a package. Pakistan on the other hand, wants to use the Grifo, but now appears to be shopping for a BVRAAM and a company willing to sell the missile to them and integrate with the radar. We will see what comes later on.

The very reason why you have quadruplex systems is devised in the first place is to provide algorhythmic redundancy, as FBW algorhythmic failure is the primary causes of crashes, not hardware system failure.

Combat survivability actually favors analog systems rather than digital, don’t you happen to know that? Digital signals are much more sensitive to interference than analog signals which tend to work based on amperage.

If something can knock down three digital systems in a row throughout an aircraft, it is very likely to knock down the fourth. Analog systems by being of a different nature from digital systems is much more likely to stand that sort of interference or failure factor other than to totally shoot down the aircraft itself.

T-98 turret structure.