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AGM-88 HARM vs LD-10 performance issues.


Hodo

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I own both the F/A-18c and the JF-17.  So I have experience with both systems.  I have come to the conclusion that either the LD-10 is over modelled and doing things it shouldn't be able to do or the HARM is under modelled and performing well below where it should.   According to the HARM tables in the Chuck's Guides for the Hornet a HARM should be able to hit a target at 50nm at 30kft from 400kts IAS.  When in game you are lucky to hit anything at 30nm from 30kft moving 400kts IAS.  Yet the LD-10 can fire that far with ease and almost matches the AGM-88 tables perfectly.  

 

I have found that the HARM is bleeding speed way to fast.  It is going at best 300-400kts when fired at that distance when it gets to the target.  Yet the LD-10 is still supersonic at that point.

 

I don't know how to explain it but the HARM is pretty bad when it comes to SEAD work out of the 4 or 5 ARM options.  If not the worst of the bunch.   Any many cases I would rather use the Sidearm for SEAD work.    

 

 

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I feel like I’m missing something here, Why should they both match each other? They are completely different missiles made from completely different technology from different countries. They don’t have the same motors or burn times they are totally different weights and shape. The only thing they share in common is they both fly and have the same role.

 

But I will agree with you I feel the AGM-88 doesn’t do the job very well.


Edited by Blinky.ben
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When using POS mode in F-16b50 with HARM, at M1.2+, at angels 45+, it won't let you fire until 36nm from target. 

So it's impossible to hit a SAM site that has a 50nm SAM range....

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If you feel the performance if off the issue probably lies in the motor data, drag wise its fine.  But well we don't exactly have much on the motor.  I promise you i've looked hard for data on the HARM's motor and have found nothing.  So for now I'd say wait for stuff like the POS modes and then see how it performs then.  

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On 3/22/2021 at 5:05 PM, Blinky.ben said:

I feel like I’m missing something here, Why should they both match each other? They are completely different missiles made from completely different technology from different countries. They don’t have the same motors or burn times they are totally different weights and shape. The only thing they share in common is they both fly and have the same role.

 

But I will agree with you I feel the AGM-88 doesn’t do the job very well.

 

Not saying they should be the same.  Just saying that the LD-10 currently matches the current range tables of the AGM-88 HARM while the HARM itself falls well short of it's ranges.  I have no issue that the LD-10 is longer range but I do have problems with the HARM doing less damage than the LD-10.  Which is a much smaller missile and warhead.  

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The LD-10 has a very optimistic drag curve last time I looked, and IMHO.   This is why it's able to hit and stick around the higher mach numbers at higher altitudes, vs. pretty much everything else.  Basically the high-mach drag coefficient drops off too fast compared to every other missile in the world.

 

I agree with @nighthawk2174 that the only data we have for the motor is the propellant weight and that it is a dual thrust (boost-sustain) arrangement.  You can go with the 70/30 rule-of-thumb split and if this doesn't give results, the high mach drag coefficient numbers might need a little bit of reduction and/or guidance needs to be adjusted to be less wasteful of the missile's energy if the missile likes to glide high and do a steep dive IRL while it does something different in-game, that could account for the range problems you're seeing ... of course it could also be a combination of everything 🙂


Edited by GGTharos
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Reminder: SAM = Speed Bump :D

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1 hour ago, GGTharos said:

The LD-10 has a very optimistic drag curve last time I looked, and IMHO.   This is why it's able to hit and stick around the higher mach numbers at higher altitudes, vs. pretty much everything else.  Basically the high-mach drag coefficient drops off too fast compared to every other missile in the world.

 

I agree with @nighthawk2174 that the only data we have for the motor is the propellant weight and that it is a dual thrust (boost-sustain) arrangement.  You can go with the 70/60 rule-of-thumb split and if this doesn't give results, the high mach drag coefficient numbers might need a little bit of reduction and/or guidance needs to be adjusted to be less wasteful of the missile's energy if the missile likes to glide high and do a steep dive IRL while it does something different in-game, that could account for the range problems you're seeing ... of course it could also be a combination of everything 🙂

 

The two biggest issues I have found with the AGM-88 is its performance not matching up with expectations based on the information charts.  And secondly the damage capabilities of that missile.  It is a 66kg warhead and sometimes on even a direct hit on a Big Bird radar or SA-19 it won't even destroy them.

 

Yet the LD-10 which has a warhead half that size.   It can easily one shot just about every radar in the game.  

 

I own both the JF and the F/A-18c. I am not calling to nerf one weapon system because I am biased.  I am calling for more realistic performance out of the weapons we have.  

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  • 2 weeks later...

And after firiring over 100 AGM-88 in MP, it has terrible terminal kill ratio/anti-AGM statistics.  I was RedFor only 10nm at 400'AGL from an emitting HK site, locked, fired 2 AGM-88s(repeated lock sequence quickly) and both were defeated by counter measures at the HK site.  (Growling Sidewinders server)  This happens EVERY time with Patriot CMs, but that makes more sense since the AGM88 is going slower, due to being fired from further away(40nm ish).
Maybe SAM site countermeasures are over modelled?

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No, your idea of SEAD is over-modeled.    Bring 7 more planes with you and open up at the same time.  In other words, bring more missiles and saturate.


Edited by GGTharos
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On 4/3/2021 at 3:22 PM, GGTharos said:

No, your idea of SEAD is over-modeled.    Bring 7 more planes with you and open up at the same time.  In other words, bring more missiles and saturate.

 

So how does the LD-10 have a better kill ratio than the AGM-88?

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Two things:   

1) It keeps more speed than it should

2) It has a smaller RCS than it ought to (IIRC)

 

all of which  which combined with the defense reaction defaults lets it slip through.


Edited by GGTharos
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[sIGPIC][/sIGPIC]

Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

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On 4/3/2021 at 8:20 PM, ACME_Widgets said:

And after firiring over 100 AGM-88 in MP, it has terrible terminal kill ratio/anti-AGM statistics.  I was RedFor only 10nm at 400'AGL from an emitting HK site, locked, fired 2 AGM-88s(repeated lock sequence quickly) and both were defeated by counter measures at the HK site.  (Growling Sidewinders server)  This happens EVERY time with Patriot CMs, but that makes more sense since the AGM88 is going slower, due to being fired from further away(40nm ish).
Maybe SAM site countermeasures are over modelled?

 

Just wanna say that the sam sites on Growling Sidewinders servers are inmortal.

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  • 2 weeks later...

Decoys (transmitters that simply transmit the same freq and possibly PRF as the target radar), shutting down the dish or SAM blinking (the target SAM site shuts off radar, another similar SAM site picks up guidance or at least surveillance for it) etc.  And of course, shooting at incoming weapons.

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On 4/20/2021 at 5:52 AM, Zergburger said:

wtf are sam site countermeasures?

Knowledge passed on from a friend who is much more knowledgeable than myself:

Active countermeasures: Sites keep their radars off and rely upon a central search radar to acquire the target (IADS)

They first turn on smaller decoy radars to try to bait a HARM/ARM shot on those rather than the main tracking radar, which comes on shortly after

And as said above, just shooting the missile down

Passive, Sidelobe reflectors: Some tech that uses Radio waves in the same frequency band to cancel out emissions to the side of the main array or passive structures that just reflect the emitted wave itself, making it harder if not impossible to shoot at the site unless its targeting/looking directly at you. This also harms use of ELINT like a HTS as you cannot triangulate an accurate position easily without being the one they are firing upon/in the bleed through.

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If youi go to F6 Missle View after firing a HARM, view from behind,  once the missle is close to the radar source, you will see often anti-missle "flak" coming up from SAM or emitter sites.

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On 4/28/2021 at 12:09 PM, CAPT_Kirkpatrick said:

Knowledge passed on from a friend who is much more knowledgeable than myself:

Active countermeasures: Sites keep their radars off and rely upon a central search radar to acquire the target (IADS)

They first turn on smaller decoy radars to try to bait a HARM/ARM shot on those rather than the main tracking radar, which comes on shortly after

And as said above, just shooting the missile down

Passive, Sidelobe reflectors: Some tech that uses Radio waves in the same frequency band to cancel out emissions to the side of the main array or passive structures that just reflect the emitted wave itself, making it harder if not impossible to shoot at the site unless its targeting/looking directly at you. This also harms use of ELINT like a HTS as you cannot triangulate an accurate position easily without being the one they are firing upon/in the bleed through.

never heard of decoy radars, i know one of the lesser talked about benefits of AESA is the small sidelobes and backlobes when compared to mechanical or even PESA systems. when you talk about sidelobe reflectors, are you talking about a physical device used to bounce sidelobes? wouldn't that mess with the automatic gain functions?


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