Operational Performance Comparison: Viper, Beagle and Stubby

[sprstdlyscottsmn]

Quite appropriately, I think I have finished my new missile simulator. Guidance is so much smoother now (previous one would end up with a lot of control oscillation). The revelation that the AIM-120D is a single pulse motor also changed a lot of my perspectives and assumptions about other missiles.

[wrightwing]

As of right now, there are only 2 AAMs that have demonstrated a longer range than AIM-120D. The Meteor and R-37. Everything else is speculation or vaporware. With the advent of VLO aircraft, the extreme range missiles became less important, as nobody is going to get BVR shots at F-22/35s. To get to the 4th generation aircraft and enablers, opponents have to get past F-22/35s. We've got 3 new AAMs under development (LREW, SACM, MSDM), which will address any "deficiencies" in magazine size/range.

[garrya]

Why is it our AAM's are consistently out-ranged by even our older weapons?
AIM-120C much less range than AIM-54
AIM-120D.... much better range (160km?) OK, but still not coming close to foreign analogues
PL-XX.... way, way longer ranged than anything we have (that's known, anyway).
As it stands, our F-15C's and SH's don't have a missile with near the BVR of say, the Iranian Fakour 90 (estimated 220 to 300km range).
Why on earth in 2019 don't we have more capable air to air weapons? Particularly given our 4th gen platforms are increasingly outclassed by the J-10C, J-16, SU-35 etc etc???

Mainly due to the collapse of Soviet
So the main threat that require missiles such as AIM-54 did not exist for decades.
Furthermore, because USA intended to operate a full stealth fighting force, it is harder to fit a long range missile inside F-35 or F-22
But the biggest factor is COST, the same reason NGM was cancelled

[garrya]

As of right now, there are only 2 AAMs that have demonstrated a longer range than AIM-120D. The Meteor and R-37. Everything else is speculation or vaporware.

IMHO, any missiles (R-40, R-33, R-77) launched from Mig-31 at Its crusing altitude and speed will have greater speed and range than AIM-120D
AIM-54 also demonstrated longer range than AIM-120D andif we speak without bias there is no way that AIM-120D can have longer range than PL-XX

[sprstdlyscottsmn]

As of right now, there are only 2 AAMs that have demonstrated a longer range than AIM-120D. The Meteor and R-37. Everything else is speculation or vaporware.

IMHO, any missiles (R-40, R-33, R-77) launched from Mig-31 at Its crusing altitude and speed will have greater speed and range than AIM-120D
AIM-54 also demonstrated longer range than AIM-120D andif we speak without bias there is no way that AIM-120D can have longer range than PL-XX

Well, don't forget that the MiG-31 is going to run face first into an AIM-120 with a closure rate of Mach 4+ before it ever detects anything to shoot at. R-40 will never have longer range.

[garrya]

Well, don't forget that the MiG-31 is going to run face first into an AIM-120 with a closure rate of Mach 4+ before it ever detects anything to shoot at. R-40 will never have longer range.

I concur if these AIM-120s were launched by stealth aircraft. But for F-15, F-16 or F-18 ? i believe Mig-31 can detect and engage them from standoff range.
What stops an R-40 launched from Mach 2.5, 75kft from having a longer range than AIM-120D launched from Mach 1-1.2, 40k ft?
IMHO, R-40 has many advantages:
a) Greater starting speed
b) Greater starting altitude
c) Bigger motor
d) Bigger wings so it can retain control at higher altitude. Thus, it can be lofted to the thinner atmosphere region.

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[sprstdlyscottsmn]

What stops an R-40 launched from Mach 2.5, 75kft from having a longer range than AIM-120D launched from Mach 1-1.2, 40k ft?
IMHO, R-40 has many advantages:
a) Greater starting speed
b) Greater starting altitude
c) Bigger motor
d) Bigger wings so it can retain control at higher altitude. Thus, it can be lofted to the thinner atmosphere region.

Well, c) is negated by the fact that it weighs three times as much as an AMRAAM. d) means it has in all likelyhood ten times the drag of an AIM-120 at any given speed, and because it is an older missile it has no loft at all. Look at the published ranges. 50-80km? And that is the MiG-25 launch profile anyway. Compare that to the AIM-120D 160km from an F-15, at best, launch profile.

The R-40 is NOT a long range missile and it never will be.

Let's look at the numbers.

3.125x the weight means it needs 3.125 times the thrust for the same duration to accelerate the same when in a zero drag environment. Having a faster start will help, but...

1.72x the diameter. This tells me it will have is three times the frontal area (drag) from this alone.

1.7x the length. if it had the SAME diameter this would mean 1.7x the surface area for skin friction (drag), but since it isn't the same diameter we are looking at 5x the drag just from the body.

3.2x the wingspan. If we remove the body diameter the wings are now 4.2x as wide. This would mean almost 18x the surface area (drag) IF they had the same fin shape, but they don't. R-40 has MASSIVE fins compared to AIM-120.

the ONLY advantages I would give the R-40 over AIM-120D is agility (not relevant to a BVR joust, this is a first shot question). There is just no way that an AIM-120D doesn't smack the MiG-31 in the face.

[rheonomic]

I am continually impressed with all your work...my own at home engineering projects are nowhere near as cool.

[garrya]

Well, c) is negated by the fact that it weighs three times as much as an AMRAAM. d) means it has in all likelyhood ten times the drag of an AIM-120 at any given speed, and because it is an older missile it has no loft at all. Look at the published ranges. 50-80km? And that is the MiG-25 launch profile anyway. Compare that to the AIM-120D 160km from an F-15, at best, launch profile.
The R-40 is NOT a long range missile and it never will be.
Let's look at the numbers.
3.125x the weight means it needs 3.125 times the thrust for the same duration to accelerate the same when in a zero drag environment. Having a faster start will help, but...
1.72x the diameter. This tells me it will have is three times the frontal area (drag) from this alone.
1.7x the length. if it had the SAME diameter this would mean 1.7x the surface area for skin friction (drag), but since it isn't the same diameter we are looking at 5x the drag just from the body.
3.2x the wingspan. If we remove the body diameter the wings are now 4.2x as wide. This would mean almost 18x the surface area (drag) IF they had the same fin shape, but they don't. R-40 has MASSIVE fins compared to AIM-120.
the ONLY advantages I would give the R-40 over AIM-120D is agility (not relevant to a BVR joust, this is a first shot question). There is just no way that an AIM-120D doesn't smack the MiG-31 in the face.

Personally, i always skeptical of published engagement range for missiles because they do not specify the situation where it can reach such range or the kind of target that it can engage at that range. Moreover, AFAIK, the max range of R-40 on Mig-25 is limited by the illuminating capability of the radar. I have no idea whether R-40 can be lofted, so i will take your words for it
R-40 is indeed heavier than AIM-120, however, it is launched from altitude 35k feet higher than AIM-120D, thus, in my opinion, gravity work in its favor instead of against it. While AIM-120 have to climb up to hit Mig-31, R-40 is surfing down to hit F-15. Hence, heavyweight help accelerates the missile
Furthermore, while R-40 is bigger than AIM-120, the air density at 75kft is 0.06 kg/m3 vs 0.245 kg/m3 at 40kft, the air at 40k ft is more than 4 times denser.

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Additionally, i think the extra fuel R-40 can carry is more than enough to solve the issue of greater drag, weight. AIM-54, R-37, R-33, RVV-BD, SM-2, SM-6 ..etc are all heavier and draggier than AIM-120, but they can all fly greater distance by carry more fuel, why would it be different with R-40?
For instance, HAWK is many time heavier and draggier than AIM-120
HAWK max range is 40-50 km whereas SL AIM-120 max range is 25-30 km.
HAWK can fly further than surface launched AIM-120 even though they are both launched from the ground where the air is significantly denser and HAWK doesn't have the advantage of higher altitude and starting speed.

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[madrat]

Part of the reason R-40 is so short range is it requires a large overtake speed in relationship to the launch aircraft.

[eloise]

Quite appropriately, I think I have finished my new missile simulator. Guidance is so much smoother now (previous one would end up with a lot of control oscillation). The revelation that the AIM-120D is a single pulse motor also changed a lot of my perspectives and assumptions about other missiles.

Can you run a simulation between AIM-54, AIM-120D and Meteor?
Can your simulator draw a speed-distance curve?

[hkultala]

What stops an R-40 launched from Mach 2.5, 75kft from having a longer range than AIM-120D launched from Mach 1-1.2, 40k ft?
IMHO, R-40 has many advantages:
a) Greater starting speed
b) Greater starting altitude
c) Bigger motor
d) Bigger wings so it can retain control at higher altitude. Thus, it can be lofted to the thinner atmosphere region.

Well, c) is negated by the fact that it weighs three times as much as an AMRAAM. d) means it has in all likelyhood ten times the drag of an AIM-120 at any given speed, and because it is an older missile it has no loft at all.

Look at the published ranges. 50-80km? And that is the MiG-25 launch profile anyway. Compare that to the AIM-120D 160km from an F-15, at best, launch profile.

The R-40 is NOT a long range missile and it never will be.

Let's look at the numbers.

3.125x the weight means it needs 3.125 times the thrust for the same duration to accelerate the same when in a zero drag environment. Having a faster start will help, but...

As it weights 3.1 times more. There is every reason to assume it can easily have also 3.1 times bigger engine with 3.1times more thrust.

1.72x the diameter. This tells me it will have is three times the frontal area (drag) from this alone.

.. with 3.1 times more weight, this means that it will have very few percent BETTER ballistic coefficient based on drag from this.

1.7x the length. if it had the SAME diameter this would mean 1.7x the surface area for skin friction (drag), but since it isn't the same diameter we are looking at 5x the drag just from the body.

Here you miscalculate badly.

The skin friction drag is about 1.72 * 1.7 x = 2.9 times more. Skin fraction is proportional to skin area, not internal volume.

This is LESS than the weight difference, so BETTER ballistic coefficient than AMRAAM from this.

3.2x the wingspan. If we remove the body diameter the wings are now 4.2x as wide. This would mean almost 18x the surface area (drag) IF they had the same fin shape, but they don't. R-40 has MASSIVE fins compared to AIM-120.

.. and these big wings also give it much less induced drag (per weight) when maneuvering. Escpecially at high altitudes.

AIM-120D trying to turn at the apogee of it's ballistic tracjectory will be needing a really high AoA and will have huge induced drag.

Also, at high supersonic speeds, the form drag is much more important than the skin friction drag.

So, your claims of "10x more drag" are total bonus. The real drag is very close to the 3.1x meaning they have quite equal ballistic coefficients.

[knowan]

R-40 is actually 2x the diameter of AIM-120; 360mm vs 180mm, not including fin diameter. That gives it 4 times the frontal area of the AIM-120.

AIM-120C-5/6/7 and AIM-120D are 356 lbs / 161.48 kg in weight, so the 480 kg R-40RD is only 2.97 times heavier.

http://www.deagel.com/Defensive-Weapons ... 76001.aspx
https://www.globalsecurity.org/military ... a/aa-6.htm
https://www.military.com/equipment/aim- ... ir-missile

[mixelflick]

Hmmm...

So it's not so cut and dried. Personally, I think the US underestimated the PK of some of the earlier Russian missiles like the R-40. It was designed a LONG time ago, yet took out an F/A-18C in the 1991 Gulf War. Yes, I know some people claim Spicher's jet's ECM went haywire, but the fact remains - it destroyed it.

Success with the R-27 series is much harder to come by. Those African engagements by Mig-29's and SU-27's did not look promising. In fact, all missed. But a lot of things could have happened there: Poor maintenance, poor airmanship, malfunction etc.. Although it's hard to imagine ALL of them malfunctioned.

As far as the R-33 is concerned, I'm not aware it's ever been fired in anger. Shame really, as it looks mighty capable and I'd like to have some data on it. The R-37? Even less real world evidence. Introduced in 1989, it was to arm the Mig-31, SU-30, SU-35 and eventually SU-57. It does look fearsome, but then again so did the Mig-25. That aircraft was no wonder weapon, but it was far from a failure/easy kill either.

Perhaps these more advanced AAM's fall into the same category..

[hornetfinn]

R-40 missile definitely doesn't have lofted profile as it doesn't have data link system for mid-course updates. Lofted profile basically requires mid-course updates if there is any hope of hitting anything at extended ranges especially with SARH missile. Basically the R-40 needed to lock on before launch or it didn't have capability to engage anything. R-33 and R-27R/ER for example do have mid-course update capability and thus can fly much more efficient flight profile. But still the manufacturer of those missiles say that much smaller RVV-SD (which is slightly larger than AMRAAM) has longer range than any R-27 model and almost matches the R-33. And R-33 is way more advanced missile than R-40 with likely a lot lower drag, better navigation and guidance systems and smaller warhead. Large wings and fins were used in all those older missiles as they had far less effective and efficient control systems. All modern missiles have a lot smaller control surfaces even if they are designed for high altitude capability.

Hawk is somewhat larger than R-40 and was also optimized for ground launch from the beginning whereas AMRAAM is air-to-air missile. Still the early MIM-23A had about the same range and altitude capability as AMRAAM today. Soviet Union was also incapable of producing equal size and range capability for their missiles at the time. Analogous to Hawk missile was SA-6, which was about the same size and also had Semi-Active homing. It had quite a bit lower range/altitude capability of MIM-23A, let alone MIM-23B. Actually even ground launched AMRAAM has longer range and altitude capability. So Hawk was much superior to Soviet missiles then when it comes to range and altitude. SA-3 had about similar or somewhat lower range/altitude performance to MIM-23A and MIM-23B with respective missile versions, but SA-3 was quite a bit bigger missile and used command guidance which takes a lot less space than SARH seeker head. Only the later SA-11 missiles had about similar altitude capability to Hawk while being only slightly larger.

So I'd bet that R-40 had significantly lower max range than AIM-120D even if fired from fast and high altitude MiG-31. R-33 might have longer range if the MiG has significant altitude and speed advantage. Of course the situation must be so that the MiG can use its superior speed and altitude capabilities. It's not like even MiG-31 normally cruises at 70,000ft and Mach 2.5. Major problem for MiG-31 would be that even the huge Zaslon radar (no matter what variant) would not give it longer reach with missiles even if they could fly for longer range. Look-down performance has never been the strong point for Russian/Soviet radars and any F-15 (especially AESA equipped) would have much longer detection/tracking range against high flying MiG-31 than other way around.