Are there any plans to reduce SD-10 performance

[Exorcet]

Back when ED corrected the AMRAAM I remember discussion between ED and Deka regarding the modeling of the SD-10. Due to differences in method the SD-10 ended up outperforming the AIM-120C despite the fact that it should be in between the 120B and C.

Are there any plans to correct this? Or will the SD-10 remain as is since it was modeled before ED decided to take over weapon modeling?

Track attached just in case.

AMRAAMvsSD10.trk

Edited July 7, 2021 by Exorcet

[nighthawk2174]

As far as i'm aware it was adjusted by ED after some work on their end and drag wise it matches what I predicted.  From what I recall it falling between the B/C is more an anecdote than anything else.  Now don't get me wrong i'm suspicious about the performance of the C, specifically its motor, but as of right now we have nothing to really challenge ED's modeling.  Maybe one day we'll get some declassified documents about its performance.

[Exorcet]

Alright then if they've already looked at it I guess they're happy with it, also good to know that the relative performance to B/C isn't something based on data, I thought it was. The only problem now would be to figure out how to stop my wingmen from dying to it as I think the last time I put F-16's up against JF-17's the AI just couldn't account for all the speed the missile had in its terminal phase.

[Blinky.ben]

GR did a comparison when they did some adjustments awhile back, keep in mind the Aim-120 has had changes sense this video was made

 

 

[Breakshot]

The SD10 is still by far the best performing missile in DCS. With the current patch ECM has now reduced the lofting effect of 120 (rightfully so), which makes the gap to 120C even bigger as the SD10 still can be manually lofted with it using variable PN logic.

 

Jeff vs Viper = dead Viper by quite the margin assuming launch conditions are the same. Throw in the fact that viper doesnt have ECM.... the performance gap is quite huge.

 

Not sure whether that is legit, but the Chinese must have made an uber missile in one try

[DCS FIGHTER PILOT]

On 7/24/2021 at 12:38 PM, Breakshot said:

The SD10 is still by far the best performing missile in DCS. With the current patch ECM has now reduced the lofting effect of 120 (rightfully so), which makes the gap to 120C even bigger as the SD10 still can be manually lofted with it using variable PN logic.

 

Jeff vs Viper = dead Viper by quite the margin assuming launch conditions are the same. Throw in the fact that viper doesnt have ECM.... the performance gap is quite huge.

 

Not sure whether that is legit, but the Chinese must have made an uber missile in one try

I conducted a simple test in game where I would fire a missile in a straight and level line and found the following.

 

At 35,000ft under standard atmospheric conditions

 

Aim-120C

Deceleration time from 2500 knots to 2000 knots~10.20 seconds

Deceleration time from 2000 knots to 1500 knots~13.65 seconds

Deceleration time from 1500 knots to 1000 knots~21.85 seconds

Total deceleration time from 2500 knots to 1000 knots~45.70 seconds

 

SD-10

2500-2000~9.05 seconds

2000-1500~12.60 seconds
1500-1000~19.20 seconds

2500-1000~40.85 seconds

 

Aim-54A/Mk60 / Aim-54C/Mk47

2500-2000~9.90 seconds

2000-1500~15.75 seconds

1500-1000~28.90 seconds

2500-1000~54.55 seconds

 

As you can see, during this simple test, the Aim-54 easily outcompetes the Aim-120C and SD-10 while the Aim-120C just barley bests the SD-10. 

As a result, during long range engagements, the Aim-54 will easily dominate (no surprises there), while the Aim-120C should beat the SD-10 PROVIDED it is launched from a fast aircraft such as the Viper, Eagle, a lightweight Hornet, and soon, the Eurofighter. Now given during this test, the missiles did not loft and did not pull any G's whatsoever. However it reasonable to assume that during long-range engagements where the missiles loft and fly in a relatively straight line, the following rankings should hold to some extent (even with the 54's lofting issue). When it comes to the terminal phase, where the missiles have to maneuver, I am not sure which one would win in a competition as I have not conducted any tests in this area. Also in regards to the current ECM modeling, I have no comment as I am certainly no expert in this area. 

 

The next very simple test that I conducted does indeed show the current gap that exists between the Aim-120C and SD-10.

Here, I launched a missile in a straight and level line as before under the following conditions,

 

Launch Altitude 35,000ft, Launch Speed Mach 1.0. 

 

Aim-120C~2240 Knots : Burn Time~6.5 seconds

SD-10~2455 Knots : Burn Time~10.0 seconds

Aim-54C/Mk47~2510 Knots : Burn Time~27 seconds

Aim-54A/Mk60~3000 Knots :Burn Time~30 seconds

 

This is where eyebrows have been raised, including my own, in regards to the AMRAAMS burn time and top speed. If @nighthawk2174 would like to comment on this, he can tell you a lot more about this than I can.

 

So in conclusion, the SD-10 is a good missile no doubt, but a long ranges where the AMRAAM is launched at high speeds, the SD-10 and thus the shooter of said missile, should be defeated while the Aim-54 on the other hand, is on a whole different level. 

Edited July 27, 2021 by DCS FIGHTER PILOT

[dundun92]

47 minutes ago, DCS FIGHTER PILOT said:

I conducted a simple test in game where I would fire a missile in a straight and level line and found the following.

 

At 35,000ft under standard atmospheric conditions

 

Aim-120C

Deceleration time from 2500 knots to 2000 knots~10.20 seconds

Deceleration time from 2000 knots to 1500 knots~13.65 seconds

Deceleration time from 1500 knots to 1000 knots~21.85 seconds

Total deceleration time from 2500 knots to 1000 knots~45.70 seconds

 

SD-10

2500-2000~9.05 seconds

2000-1500~12.60 seconds
1500-1000~19.20 seconds

2500-1000~40.85 seconds

 

Aim-54A/Mk60 / Aim-54C/Mk47

2500-2000~9.90 seconds

2000-1500~15.75 seconds

1500-1000~28.90 seconds

2500-1000~54.55 seconds

 

As you can see, during this simple test, the Aim-54 easily outcompetes the Aim-120C and SD-10 while the Aim-120C just barley bests the SD-10. 

As a result, during long range engagements, the Aim-54 will easily dominate (no surprises there), while the Aim-120C should beat the SD-10 PROVIDED it is launched from a fast aircraft such as the Viper, Eagle, a lightweight Hornet, and soon, the Eurofighter. Now given during this test, the missiles did not loft and did not pull any G's whatsoever. However it reasonable to assume that during long-range engagements where the missiles loft and fly in a relatively straight line, the following rankings should hold to some extent (even with the 54's lofting issue). When it comes to the terminal phase, where the missiles have to maneuver, I am not sure which one would win in a competition as I have not conducted any tests in this area. Also in regards to the current ECM modeling, I have no comment as I am certainly no expert in this area. 

 

The next very simple test that I conducted does indeed show the current gap that exists between the Aim-120C and SD-10.

Here, I launched a missile in a straight and level line as before under the following conditions,

 

Launch Altitude 35,000ft, Launch Speed Mach 1.0. 

 

Aim-120C~2240 Knots : Burn Time~6.5 seconds

SD-10~2455 Knots : Burn Time~10.0 seconds

Aim-54C/Mk47~2510 Knots : Burn Time~27 seconds

Aim-54A/Mk60~3000 Knots :Burn Time~30 seconds

 

This is where eyebrows have been raised, including my own, in regards to the AMRAAMS burn time and top speed. If @nighthawk2174 would like to comment on this, he can tell you a lot more about this than I can.

 

So in conclusion, the SD-10 is a good missile no doubt, but a long ranges where the AMRAAM is launched at high speeds, the SD-10 and thus the shooter of said missile, should be defeated while the Aim-54 on the other hand, is on a whole different level. 

 

Youve completely ignored, however, that the lofting manuever is TOF limited, and the SD-10 has a full 20s battery advantage over an AMRAAM. This allows lofted shots from much further away, as with the current missile drag modeling missiles can cruise basically at high altitude as long as the battery allows when lofting.

 

Another note is that the SD-10s motor profile (longer burn time and greater total impulse) and heavier weight help it in the lofting phase more than the AMRAAM

Edited July 27, 2021 by dundun92

[nighthawk2174]

7 hours ago, DCS FIGHTER PILOT said:

I conducted a simple test in game where I would fire a missile in a straight and level line and found the following.

 

At 35,000ft under standard atmospheric conditions

 

Aim-120C

Deceleration time from 2500 knots to 2000 knots~10.20 seconds

Deceleration time from 2000 knots to 1500 knots~13.65 seconds

Deceleration time from 1500 knots to 1000 knots~21.85 seconds

Total deceleration time from 2500 knots to 1000 knots~45.70 seconds

 

SD-10

2500-2000~9.05 seconds

2000-1500~12.60 seconds
1500-1000~19.20 seconds

2500-1000~40.85 seconds

 

Aim-54A/Mk60 / Aim-54C/Mk47

2500-2000~9.90 seconds

2000-1500~15.75 seconds

1500-1000~28.90 seconds

2500-1000~54.55 seconds

 

As you can see, during this simple test, the Aim-54 easily outcompetes the Aim-120C and SD-10 while the Aim-120C just barley bests the SD-10. 

As a result, during long range engagements, the Aim-54 will easily dominate (no surprises there), while the Aim-120C should beat the SD-10 PROVIDED it is launched from a fast aircraft such as the Viper, Eagle, a lightweight Hornet, and soon, the Eurofighter. Now given during this test, the missiles did not loft and did not pull any G's whatsoever. However it reasonable to assume that during long-range engagements where the missiles loft and fly in a relatively straight line, the following rankings should hold to some extent (even with the 54's lofting issue). When it comes to the terminal phase, where the missiles have to maneuver, I am not sure which one would win in a competition as I have not conducted any tests in this area. Also in regards to the current ECM modeling, I have no comment as I am certainly no expert in this area. 

 

The next very simple test that I conducted does indeed show the current gap that exists between the Aim-120C and SD-10.

Here, I launched a missile in a straight and level line as before under the following conditions,

 

Launch Altitude 35,000ft, Launch Speed Mach 1.0. 

 

Aim-120C~2240 Knots : Burn Time~6.5 seconds

SD-10~2455 Knots : Burn Time~10.0 seconds

Aim-54C/Mk47~2510 Knots : Burn Time~27 seconds

Aim-54A/Mk60~3000 Knots :Burn Time~30 seconds

 

This is where eyebrows have been raised, including my own, in regards to the AMRAAMS burn time and top speed. If @nighthawk2174 would like to comment on this, he can tell you a lot more about this than I can.

 

So in conclusion, the SD-10 is a good missile no doubt, but a long ranges where the AMRAAM is launched at high speeds, the SD-10 and thus the shooter of said missile, should be defeated while the Aim-54 on the other hand, is on a whole different level. 

 

Motor wise I do have doubts about the 120's burn time and thrust it produces but well there's nothing to prove ED's current modeling wrong for now.  Same for the battery life, the 80 seconds comes from the vipers manual but it is for the 120B not the C.  And considering the C got a new seeker and newer electronics I have a suspicion its battery life is longer than that of the B.  But again there is nothing that we have access too to see if this suspicion is correct. The SD10 is probably fine as we should keep in mind its a larger missile than the sparrow.  The only error is that its supposed to have a dual stage motor that burns at different times.  The initial boost is supposed to burn out and the motor re-ignited latter on to get the missile up to a higher speed for terminal intercept.  At least that's how Deka has described its operation.

[Cmptohocah]

On 7/28/2021 at 2:17 AM, nighthawk2174 said:

Same for the battery life, the 80 seconds comes from the vipers manual but it is for the 120B not the C.

Unless I am wrong, this info comes from datalink's duration, and I guess that DL would last longer than expected battery life simply 'cause of safety factor. I mean you can't afford to brake off DL if the missile battery might be still in operation.

Also, what does 120 use to power the actuators while maneuvering?

 

[GGTharos]

On 7/28/2021 at 7:25 PM, Cmptohocah said:

Unless I am wrong, this info comes from datalink's duration, and I guess that DL would last longer than expected battery life simply 'cause of safety factor. I mean you can't afford to brake off DL if the missile battery might be still in operation.

Also, what does 120 use to power the actuators while maneuvering?

 

 

The DL on the F-15C is transmitted until 'drop dead time' which is ~100sec.   Don't quote me on it, going by memory.

[Cmptohocah]

Looking from strictly energy point of view: shouldn't the missile have shorter range if maneuvering compared to the one that is not? I mean, the missile has certain amount of internal energy and if some of that energy is used to actuate the control surfaces than the effective range should be different, or at least maneuverability should be reduced - depending on the energy source.

[Exorcet]

16 minutes ago, Cmptohocah said:

Looking from strictly energy point of view: shouldn't the missile have shorter range if maneuvering compared to the one that is not? I mean, the missile has certain amount of internal energy and if some of that energy is used to actuate the control surfaces than the effective range should be different, or at least maneuverability should be reduced - depending on the energy source.

Harsh maneuvers will drain energy, but some can be beneficial (this is partly why lofting works). A missile will have an optimum L/D AoA like a plane.

 

On 7/27/2021 at 7:17 PM, nighthawk2174 said:

The only error is that its supposed to have a dual stage motor that burns at different times.  The initial boost is supposed to burn out and the motor re-ignited latter on to get the missile up to a higher speed for terminal intercept.  At least that's how Deka has described its operation.

That's what I've heard too. It would nice if it was simulated, since I think right now with all the thrust being front loaded the missile ends up covering ground faster than it would other wise. The lower mass from having burned all the fuel also helps the SD-10's agility compared to if it still had some extra mass on board.

[GGTharos]

Pretty sure the SD-10 has a boost-sustain grain, not a dual pulse motor.  The dual pulse is more off a PL-15 thing.

1 hour ago, Cmptohocah said:

Looking from strictly energy point of view: shouldn't the missile have shorter range if maneuvering compared to the one that is not? I mean, the missile has certain amount of internal energy and if some of that energy is used to actuate the control surfaces than the effective range should be different, or at least maneuverability should be reduced - depending on the energy source.

 

The easiest missile to look at here would be the sparrow - it has an open loop hydraulic actuation for its control surfaces, meaning the amount of hydraulic fluid onboard is drained to perform maneuvers.   But in any case, unless we're talking about very old missiles, you can expect control surfaces to be operational as long as the missile operation time - they could be active for longer in theory, but they won't be active for less time than that.

Edited August 1, 2021 by GGTharos

[Cmptohocah]

9 hours ago, GGTharos said:

...But in any case, unless we're talking about very old missiles, you can expect control surfaces to be operational as long as the missile operation time - they could be active for longer in theory, but they won't be active for less time than that.

 

AIM-120 for example has electro-mechanical actuators which are powered by Li-Al batteries (4 of them). Assuming that these batteries are not used to power other systems, the question is: how much energy do they have stored? Is it enough to perform heavy maneuvering throughout the flight envelope? Does it have overhead to be the last system to drain out, after all others have been exhausted, while being used under XX% of the load for XX% of flight time?

[GGTharos]

Unless you find evidence to the contrary, the answer is 'it has the power to do whatever it needs to do'. 

[DCS FIGHTER PILOT]

On 8/1/2021 at 4:27 PM, Exorcet said:

That's what I've heard too. It would nice if it was simulated, since I think right now with all the thrust being front loaded the missile ends up covering ground faster than it would other wise. The lower mass from having burned all the fuel also helps the SD-10's agility compared to if it still had some extra mass on board.

It would have less agility if it stored that extra fuel up for the terminal attack phase but it would decelerate at a lower rate. 

[GGTharos]

Less agility compared to what?   I don't think the target will care in the least if the missile can pull 1-2 aoa and 1-2g less in this case, it would make no difference compared to losing a lot more performance without the second pulse.

[Exorcet]

On 8/2/2021 at 5:37 PM, DCS FIGHTER PILOT said:

It would have less agility if it stored that extra fuel up for the terminal attack phase but it would decelerate at a lower rate. 

In a straight line the inertia would keep the missile's speed up (but it would be slower from burning less fuel in the first place), but in turns induced drag would be higher. For a single turn this would be negligible like GG mentioned, but it could matter if the missile is forced to maneuver between motor burns.