AIM-120 AMRAAM vs SD-10, the new DCS rivalry? (updated)

Coming from more of a WWII flight simulation background, the modern combat simulation arena is interesting because not only are the flight models of various aircraft compared but so too are the types of armament that they carry. The new rivalry is between the new active radar veteran, the AIM-120 AMRAAM versus the new up and coming SD-10. There are a few interesting discussions to check into and I thought I’d summarize some information here.

A long standing discussion

A J-11A fires an R-77 missile

For as long as I’ve been following DCS World, missile performance has been a traditional subject of debate and discussion. Some of it heated as I’m sure you can imagine. The arguments of the past have revolved around the R-27 (and it’s various sub-variants) semi-active missile, the AIM-7 Sparrow (though it seems to far more rarely factor into the discussion), the R-77 active-radar missile, and the AIM-120B and AIM-120C all modeled into DCS World.

Enter the SD-10, a Chinese export missile based on the PL-12, which has upended the conversation and brought some familiar talking points back into the light.

A JF-17 packing a single SD-10 missile on the outer wing pylons (and PL-5E’s on the wingtips).

I’ve long exhausted my interesting arguing numbers and there are people out there with far more knowledge of the aerodynamics and various factors that matter when it comes to things like missile maneuverability and maximum range. For the sake of a few arguments, however, we have it on good authority and confirmed via various sources that the new SD-10 should have a range that is sandwiched somewhere between the AIM-120B and AIM-120C.

Since the launch of the DCS: JF-17 (and its SD-10 missiles), the charge has been leveled that the SD-10 is outperforming even the AIM-120C for range and that this is now an unrealistic situation. To that end, Eagle Dynamics has been promising updates to all missile performance based on new research, and some changes have just been implemented.

A quick primer on the subject

If you’re not one for the details on these kinds of things, I have been using a few terms that may not be immediately familiar. So before I go on, let’s talk very quickly about types of missiles.

There are three types of missile seekers conventionally used. An infrared missile seeker looks for the hot engines and other components of a jet fighter or aircraft to track it’s target. These are typically shorter range missiles like the AIM-9, R-60, R-73, and PL-5E (in DCS World) but also the R-27T and R-27ET which are a medium range missile that also employs IR tracking.

Semi-active radar missiles use radar signals bouncing off of the firing aircraft’s radar to track the target. This requires the firing aircraft to maintain a direct radar lock with the target for the entire life span of the missile. These are typically associated with older missiles such as the AIM-7 Sparrow and the R-27R an R-27ER.

Finally, we have active radar missiles such as the AIM-120 AMRAAM, R-77 and SD-10 (PL-12) which all have their own radar onboard the missile that can be used to track the target. Conventionally, these missiles can be locked and fired at targets greater than the range of their own radar and can be guided into position for their own radar to then take over. This is known as “going active” or “pitbull” in fighter pilot speak.

The ranges that these missiles work at vary according to a very long list of variables. Altitude and air density, the aspect of the missile from firing aircraft to target aircraft, if the target aircraft is turning or not, and the speeds of the two aircraft are just some of the variables. Two aircraft at mach 1.0 at sea level engaged in a tail chase may not have very much range at all while two aircraft flying at 50,000 feet flying at mach 1.0 directly at each other will have far more range. The exact numbers are a mix of complex calculations and missile seeker logic – much of which is classified. Simulations such as DCS World have to make guesses to make it work.

The latest changes

F/A-18C going for the full AMRAAM treatment.

Eagle Dynamics has long said that they were going to implement updates to missile calculations that should bring the various performance levels in different situations to be more accurate to real world performance levels.

The first of those changes just arrived in the latest open beta with the following notes:

  • Corrected flight dynamics of AIM-120 missiles based on our latest CFD research.
  • All changes increased the launch range by about 10-20%.
  • AIM-120C: reduced subsonic and transonic zero-lift drag, reduced lift-induced drag, increased lift.
  • AIM-120B: reduced lift-induced drag, increased lift.

Those notes have then been tested by the community with some inconsistent results that seem to suggest that the update didn’t quite work out the way it was intended to. A thread on r/hoggit has attracted some attention after graphs were posted suggesting that the missile performance was down (some of you may say nerfed).

DCS community manager NineLine has weighed in saying:

We are still seeing some weird things with the 120s, work is ongoing.

Nineline on r/Hoggit

Also in the thread is a comment from non other than Nick Grey, owner/founder of Eagle Dynamics, who adds a lot of detail to the conversation and the types of tools they are using to update their missile calculations. He says the following:

Dear Sir and Community members, many thanks for your support and feedback. Please note that the SD-10 also has WIP issues, especially pertaining to drag, both parasitic and induced. We are finishing the full Flow Dynamics on this and other missiles in order to have a detailed discussion with our good friends at DEKA and HB in the near future. FYI we use both Ansys Fluent and Flow Vision software for our FM calculations for both AC and missiles. In Q1 of 2020, we plan to make available all our CFD calculations, performance graphs and data sets for most of our missiles and AC in DCS. We have set ourselves a hard target of delivering to you the most reliable and precise missile FM and guidance laws in order to put any uncertainty or lack of clarity to bed. This work is being done with the assistance of all our SME’s and ‘friends’ in industry and while not all data is openly available, our aerodynamics and missile specialists will deliver a very scientific report for those of you who wish to cross-examine our calculations and findings in detail. Our goal is to move closer and closer to reality where and when possible and to deliver enhanced combat realism and customer satisfaction. That goes for airframe aerodynamics, engines and systems as well. We know we have a long way to go but we are committed to continuing in this direction with purpose. Once again thanks to you and all our passionate community we hope to achieve a level of excellence which may be up to your expectations. We really appreciate your commitment and devotion to DCS, thank you again. Merry Christmas and Happy New Year to you and your families. Kind regards, Nick

Nick Grey on r/Hoggit

The bigger picture

Going from the various comments from Eagle Dynamics employees and team members from Deka Ironworks, Heatblur, and others, it’s clear that recent additions to DCS World have increased the number of models of missiles being slung in single player and multiplayer matches and that has required DCS World as a simulator to make some changes to the way that they handle missiles.

As it is, Heatblur has had to do a few things with their AIM-54 Phoenix implementation to make that missile work in DCS World and it isn’t without it’s own set of glitches. They, Deka Ironwork Simulations, and others are now giving the impression that they are all working with Eagle Dynamics to increase the realism in the simulator and adapt to features and systems that just weren’t part of the plan when DCS World, and Lock On: Modern Air Combat before it, last approached this subject in detail.

As always, things are a work in progress on this and it sounds like there is renewed emphasis to sort issues out in this area of the simulation. An emphasis that we may not have seen in the past where the situation was fairly entrenched and stable. New additions to the series are requiring some readjustments – and that’s not a bad thing.

Update: December 21 at 11:27 pm EST

The first video testing the new missile performance values is out with a great walkthrough of a BVR fight featuring the AMRAAM and SD-10 including a breakdown of the missile performances in a Tacview replay at the end. Worth watching and some great content from Growling Sidewinder.

A video from the Grim Reapers also does a ballistic comparison of the SD-10, AIM-120 and the R-77.

3 Comments Add yours

  1. Voyager says:

    It’s good to see that they’re going to be making the missile data they can open. I’ve argued elsewhere that making essential but non revenue generating/non-differentiating parts of sim systems open source would likely benefit the companies more that keeping them closed, because it allows more eyes on the problems, which helps them get solved quicker.

    I do hope this works out well for them.

    Liked by 2 people

    1. ShamrockOneFive says:

      I hope so too!

      Like

  2. Blue 5 says:

    People with whom I fly have also suggested that the JF-17 ARM is also surprisingly effective.

    Like

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