Operational Performance Comparison: Viper, Beagle and Stubby

[aussiebloke]

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.

It is worth noting that one account, purportedly from the Iraqi pilot who shot down Speicher, indicates the missile engagement took place at a relatively short range:

I locked a target 38Km ( 20nm ) from me and at 29Km ( 15nm ) I fired R-40RD missile from my under Rt. wing

viewtopic.php?p=300347#p300347

[sprstdlyscottsmn]

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

I can draw a speed-distance curve, but I do not have an AIM-54 modeled as it is outside the current scope of my comparison.

[sprstdlyscottsmn]

So I set up a few launches with both shooter and target flying at 36,000ft at 1.2M (a Tu-22 maybe)

First a few notes on the flight paths. The AMRAAM is using a single 8s pulse at constant thrust and a 20 degree loft. The Meteor uses a 2s boost followed by a nominal 30s sustaining ram-rocket with a 4 degree loft. Due to being constrained to using atmospheric oxygen I could not give it a higher loft as it would fly too high due to the long motor burn time. The throttleable motor has a maximum and minimum thrust and tries to keep the Meteor at both Mach 3 and a speed sufficient to have maximum q for turning. Additionally, if the predicted time to impact is less than the potential remaining time for maximum thrust then the motor will open completely.

The first setup was a 100nm launch for both the AIM-120D (Blue) and Meteor (Red). In this shot, the high loft of the AIM-120D gives it a higher average speed but the Meteor hits with a higher speed. Interestingly, with this setup the Meteor runs out of fuel at the moment of impact.

When I realized that the Meteor had just run out of fuel I setup a 140nm launch for the air breathing missile.

[swiss]

Thanks Spurts!

[eloise]

So I set up a few launches with both shooter and target flying at 36,000ft at 1.2M (a Tu-22 maybe)
First a few notes on the flight paths. The AMRAAM is using a single 8s pulse at constant thrust and a 20 degree loft. The Meteor uses a 2s boost followed by a nominal 30s sustaining ram-rocket with a 4 degree loft. Due to being constrained to using atmospheric oxygen I could not give it a higher loft as it would fly too high due to the long motor burn time. The throttleable motor has a maximum and minimum thrust and tries to keep the Meteor at both Mach 3 and a speed sufficient to have maximum q for turning. Additionally, if the predicted time to impact is less than the potential remaining time for maximum thrust then the motor will open completely.
The first setup was a 100nm launch for both the AIM-120D (Blue) and Meteor (Red). In this shot, the high loft of the AIM-120D gives it a higher average speed but the Meteor hits with a higher speed. Interestingly, with this setup the Meteor runs out of fuel at the moment of impact.
When I realized that the Meteor had just run out of fuel I setup a 140nm launch for the air breathing missile.

thanks you Spurts, i love your analyze but can you explain what are the parts inside the circle? it is a bit confusing
btw, can you use a different color for 140 nm loft profile? it is rather hard to distinguish with 100 nm launch
can you run the simulation with the same altitude and speed for the shooter but the target is Mig-31

Capture5.PNG (159.65 KiB) Viewed 27136 times

[sprstdlyscottsmn]

The circled area is the 140 nm Meteor launch. If I make it a different color entirely it muddles the 100 nm Meteor launch data, so I made it the same color at 50% transparency. I see that I accidentally made the 140 nm Meteor launch Mach data dotted when I did not mean to.

[eloise]

The circled area is the 140 nm Meteor launch. If I make it a different color entirely it muddles the 100 nm Meteor launch data, so I made it the same color at 50% transparency. I see that I accidentally made the 140 nm Meteor launch Mach data dotted when I did not mean to.

i understand
btw can you run the simulation with the shooter flying at 20,000ft at 1.2M but the target flying at 75,000 ft at 2.5 M

[sprstdlyscottsmn]

I already did personally. I'll graph the results...

*EDIT* why 30k? That seems pretty unrealistic to me. The RCS of the MiG-31 ensures it can be seen from a long distance, giving the shooter time to accelerate and climb.

[eloise]

I already did personally. I'll graph the results...

*EDIT* why 30k? That seems pretty unrealistic to me. The RCS of the MiG-31 ensures it can be seen from a long distance, giving the shooter time to accelerate and climb.

That is actually a mistake, i wanted to write 20,000 feet
This is the reason:

Fighter's radar are useless against stealth fighter, but no aircraft is stealthy in infrared. However, IRST can't detect object through cloud cover. In other words, a conventional fighter can't attack a stealth aircraft fly just below cloud level. Unfortunately, most clouds is 20,000 feet or lower while 4.5 gen fighter can fly at 40,000-50,000 ft and interceptor such as Mig-31 can fly at 75,000 ft. That bring us to the question: what is the maximum distance that an F-35 fly under cloud cover at 20,000 ft can attack a target flying at 50,000 ft at Mach 1.4 ? and what if the target was at 75,000 ft at Mach 2.5?. I want to see if fly under the cloud level is a viable tactic or missile range become 1-2 km

I also like to see the scenario when legacy fighter such as F-16, F-15 attack Mig-31, should we try 45,000 ft at Mach 1.5 for the shooters?
P/s: I'm really sorry for changing number constantly hope you don't hate me

[sprstdlyscottsmn]

The answer is "no". And there is no need to. F-35 does have reduced IR signature built into it, but as you say nothing is invisible in IR. Even if you took the stated head on value for the OLS-35 and argued that flying at 1.2M causes enough friction to negate the IR reduction (not a terrible argument to start with) you are still looking at a head on detection range of merely 35km or 19nm. That is with a sky background. Expect "look down" range to be reduced.

I did a range of 1.2M launches from 30,000-50,000ft in 5,000ft increments and then threw in a 60,000ft shot from 1.6M to show why it's great to be the F-22. All shots had a launch range of 150nm.

As we can see, every shot makes it to altitude even if the MiG-31 has to cover half the distance for the 30k launch. Even if we assume the shooter keeps flying at 1.2M right into the MiG, the range at MiG destruction is still 38nm and outside IR detection range by a factor of two.

My sim also gives a Pk of a shot based on available maneuverability (dynamic pressure) and closure rates. Starting with the 30k shot, the Pk was 7%, 14%, 24%, 36%, 48%, and 78% for the F-22 shot. Pk is never above 78% as I assume that to be the overall missile Pk for the AMRAAM. 92% chance of success in each of launch, guidance, and fusing.

Other note on AMRAAM guidance. For long range shots the missile pitches to 20 degrees for loft while the motor is burning. Once the motor is no longer burning the missile goes ballistic (zero pitch input) to minimize drag. It stays ballistic until either the mid-course updates tell it that it is pointed at the expected impact position or the target enters the seeker range and FOV.

[marsavian]

What would the above graphs look like if the Mig-25 was flying away at Mach 2.5 rather than coming towards you at that speed, i.e. what would be the maximum range of each shooter speed/altitude combination then ? Great work btw, much appreciated.

[sprstdlyscottsmn]

Leave that shot for the F-22. A MiG-25/31 running away isn't a threat, follow it with an F-35 and bomb it on the ground.

[swiss]

The answer is "no". And there is no need to. F-35 does have reduced IR signature built into it, but as you say nothing is invisible in IR. Even if you took the stated head on value for the OLS-35 and argued that flying at 1.2M causes enough friction to negate the IR reduction (not a terrible argument to start with) you are still looking at a head on detection range of merely 35km or 19nm. That is with a sky background. Expect "look down" range to be reduced.

I did a range of 1.2M launches from 30,000-50,000ft in 5,000ft increments and then threw in a 60,000ft shot from 1.6M to show why it's great to be the F-22. All shots had a launch range of 150nm.

Capture6.PNG

As we can see, every shot makes it to altitude even if the MiG-31 has to cover half the distance for the 30k launch. Even if we assume the shooter keeps flying at 1.2M right into the MiG, the range at MiG destruction is still 38nm and outside IR detection range by a factor of two.

My sim also gives a Pk of a shot based on available maneuverability (dynamic pressure) and closure rates. Starting with the 30k shot, the Pk was 7%, 14%, 24%, 36%, 48%, and 78% for the F-22 shot. Pk is never above 78% as I assume that to be the overall missile Pk for the AMRAAM. 92% chance of success in each of launch, guidance, and fusing.

Other note on AMRAAM guidance. For long range shots the missile pitches to 20 degrees for loft while the motor is burning. Once the motor is no longer burning the missile goes ballistic (zero pitch input) to minimize drag. It stays ballistic until either the mid-course updates tell it that it is pointed at the expected impact position or the target enters the seeker range and FOV.

Great Work. I assume this is for the AMRAAM-D.

[sprstdlyscottsmn]

Yes, this is my AIM-120D model.

On the running away Fox(bat/hound) the F-22 could take that shot from as far away as 75nm and the missile will still have 0.92M closure on impact (156nm from launch). A 40k 1.2M shooter would need to be ~12nm away to hit him.

[marsavian]

Wow, so initial height and speed really make a difference when chasing an opponent down rather than one heading your way. So am I right in assuming from your earlier graphs that you estimated the Meteor's maximum range as 40% more than the AIM-120D ?