AIM-54 Probability of Kill – IV – Medium and Long Range

This is the last set of test about the Probability of Kill model for the AIM-54A Mk60 and the AIM-54C Mk60. The previous articles introduced the modus operandi and the criteria of the tests, studied the low altitude performance and went into the details of the effect of the altitude at a fixed range. This article studies the performance of the AIM-54 at longer ranges: 30nm, 35nm, 40nm, 45nm. As usual, each set of tests is composed of 120 AIM-54A Mk60 and 120 AIM-54C Mk47. The total amount of AIM54 launched is 1920.

Raw Data

Usual routine here, a look at the raw data (the complete raw data series will be available in PDF format as the study is completed. It’s simply too long to be posted here):

rio14-AIM-54-PK-res-raw
AIM-54C Mk47 (left column) and AIM-54A Mk60 (right column)

And now a condensed form:

rio14-AIM-54-PK-res-AIM-54C
AIM-54C Mk47: 20,000ft and 30,000ft

rio14-AIM-54-PK-res-AIM-54A
AIM-54A Mk60: 20,000ft and 30,000ft

Analysis: Charts

There are multiple ways to look at the data. Considerations can be made in regards of the Altitude Δ performance, how each version performs in specific scenarios and how the WCS Guidance as a function of the distance affects the ultimate result.
I also decided to use normalized data when possible in order to reduce the number of less meaningful charts (this article is long enough already!).

NOTE: The legend marks the series by reporting two letters to better identify them: “C” for the AIM-54C Mk47 and “A” for the AIM-54A Mk60 plus “L” for Low Altitude test at 20,000ft and “H” for High Altitude, 30,000ft.

Combined Hit rate

The following is the combined chart for the Hit Rates. As we know from the previous studies, it is the least meaningful because the PK changes so much as the altitude and aspect of the target change.
rio14-AIM-54-PK-chart-hitrate-combined

Hot Aspect Hit rate

This chart shows the hit rate from Hot-aspect targets at different altitudes and ranges.
rio14-AIM-54-PK-chart-hitrate-hot
The PK increases for the AIM-54C Mk47 from 35nm and then it is fairly stable. The AIM-54A Mk60 follows a similar pattern with an offset towards longer ranges.
The increased performance of each version at 45nm, 30,000ft, especially for the AIM-54C Mk47, may be related to the odd case of the MiG-29S I cover later on. That aside, it is interesting to note how the results are fairly similar and consistent between 35nm and 45nm.

Flanking Aspect Hit rate

This scenario shows some interesting results. The Flanking scenario is the test that pushes the performance of the rocket motor to the limits because the closure rate is not as high as it is in the Hot aspect tests.
rio14-AIM-54-PK-chart-hitrate-flanking
It is interesting to note how the AIM-54A Mk60 at high altitude shows fairly constant results. This is due to the fact that this version of the Phoenix has the most powerful rocket motor and the air at higher altitudes is thinner.
As expected, the missile that suffers the most as the range increases is the AIM-54C Mk47, especially at 20,000ft. At higher altitudes instead, it manages to perform well up to 40nm. This number can be considered the limit of the employment of the AIM-54C at high altitude versus a manoeuvering target.
Eventually, at 20,000, the increasing range affects the AIM-54A Mk60 as well, dragging the PK down post 40nm.

Miss rate: AIM-54C Mk47

Let’s now focus on the reason why a missile was defeated. The following are the results of the Phoenix-C.
This chart plots the number of defeated Phoenixes versus the total tests per scenario (120). Therefore, the lower the result, the better.
rio14-AIM-54-PK-chart-missrate-AIM54C
This is a peculiar chart because it gives the impression that, the longer the range, the more effective the seeker of the missile is. What I think has happened is that, as the range increased, more missiles have been defeated kinetically even before having the chance of having their seeker defeated. This was a rather common occurrence at longer ranges.

Miss rate: AIM-54A Mk60

The AIM-54A Mk60 and its more powerful rocket motor shows its muscles but, nevertheless, it still shows the same symptoms of the AIM-54C Mk47.
rio14-AIM-54-PK-chart-missrate-AIM54A

The “Sweet spot”

We can define a “sweet spot”, a range where the missile performance is consistent no matter the altitude and the aspect of the target. This value, for the AIM-54C Mk47 at medium to long ranges, is approximately 35nm. The equivalent for the AIM-54A Mk60 is slightly closer to 40nm. Interestingly, I would expect this value to be much closer to 45nm but it is clear how the range affects the latter Phoenix as well, especially if the target is either Flanking or Notching.

Analysis: Range and additional considerations

The following are considerations related to single or very similar sets of tests, some pertinent to range observations, some other about specific behaviour of the targets.

Range: 30nm

The results of the tests made at this range are inferior to the expected. Both versions of the AIM-54, in fact, show poorer results at 30nm than 25nm (by interpolation) or 35nm+.
The following are some screenshots from Tacview:

The AI seems to have an easier time defeating the seeker of the AIM-54 at this range. Moreover the Phoenix can still be defeated kinetically.

rio14-AIM-54-PK-miss-A-30nm-20000-ntch-fa18-energy
AIM-54A vs F/A-18: 30nm, 20000ft, Notching. AIM-54 out of energy.

Range: 35nm

At 35nm, the Phoenix takes full advantage of the peculiar trajectory it follows, guided by the AWG-9 WCS. The first “hint” of such guidance appears at 20nm.
This allows the missile to travel farther by converting speed in altitude, in order to later dive onto the target.

Range: 40nm and 45nm

These are the ranges that make low-altitude launches less and less reliable the farther we are from the target. This is even more real if the target is either moving away or closing at a limited closure speed.
The success of the launch also depends on how the target reacts to the threat: the target simply has to turn cold and gain speed to defeat the missile. Sometimes, simple manoeuvres are enough have the missiles wasting almost entirely of its limited energy.


However, this is not always the case. The AIM-54, thanks to its trajectory, is capable of defeating an aircraft farther than 45nm, especially if the target is not defending by moving away from the missile.

The Hunchback of Eagle Dynamics

You may have noticed that, the farther the range, the more accentuated is the “hump” in the AIM-54 TAS Tacview chart. Those “humps” represent a massive drop of energy, something that in real life I don’t really think should happen. The magnitude of the energy wasted is even more understandable by plotting the G-forces sustained by the missile.
The following are a series of launches at 30nm, 35nm and 40nm at a constant altitude of 20,000ft. The charts display G-force and TAS.

The first “G-spike” occurs as the Phoenix leaves the rail. The second as it terminates its climbing phase of the trajectory. The amount of wasted energy is considerable.

Another issue with the current implementation of the Phoenix is the guidance: the WCS should command the AIM-54 to go pitbull but at the moment the AIM-54 behaves as an AIM-120 and goes active automatically at a certain distance. Moreover, the AIM-54 should be turned active much earlier, freeing the F-14 to pursue other targets, turning cold or following up with a second launch.
Some people argue that the AIM-54 is too easy to use due to its 120-like behaviour. Personally, I’d barter that right now in exchange for a cleaner trajectory (hence more Energy) and an earlier activation time, resulting in a much more threatening and performing weapon.

According to Heatblur, these issues are due to their lack of complete access to the missiles code. I really hope that HB will soon be allowed to work on the AIM-54!

MiG Quo Vadis?

The MiG-29S at 45nm behaved in an unexpected way. As every other aircraft, as the Phoenix turned active, it defended by dispensing chaffs and manoeuvring. Then, a few seconds later, it resumed its original flight path, without caring for the incoming AIM-54. Sometimes it has been lucky, especially versus the AIM-54C Mk47 and its less powerful rocket motor. In most other cases, it simply played the role of the sitting duck.
I have no explanation for such behaviour. I can imagine that the missile’s seeker illuminated a blind spot in the sensor coverage of the MiG-29.

rio14-AIM-54-PK-hit-A-45nm-30000-ntch-mig29-what2

rio14-AIM-54-PK-hit-A-45nm-30000-ntch-mig29-what

Conclusions

If you are wondering which version of the AIM-54 is the “the best” between 30nm and 45nm, your question won’t find an answer here. The real answer is: depends. Depends on the tasking, the type of gamer you are (milsim rather than casual) and the server or mission you are flying. The AIM-54A Mk60 has proved to be a great missiles when the target is not “hot” due to its powerful rocket motor but, whenever the energy hasn’t been a factor, the AIM-54C has scored on par PK. Therefore, if you play on casual servers such as GAW, then the AIM-54A Mk60 is definitely the better option. In a more sim-oriented environment, where ROE are in place, the target is intercepted according to specific parameters, often dictated by a superior controller, and VID is often required, the AIM-54C Mk47 may be the better option. Moreover, in this kind of environment, the SA is generally much higher and the smokeless motor of the AIM-54C Mk47 is undoubtedly a plus.


Building the AIM-54 PK Model

With a total of 3360 samples, the PK model is taking shape.
The histogram is still the best chart to display the results due to the lack of tests at 15nm and 20nm but I include line plots as well. I may do additional tests to cover such gaps at a later time.

AIM-54C Mk47

Combined results:

This slideshow requires JavaScript.

Hot aspect:

This slideshow requires JavaScript.

Flanking aspect:

This slideshow requires JavaScript.

AIM-54A Mk60

Combined results:

This slideshow requires JavaScript.

Hot aspect:

This slideshow requires JavaScript.

Flanking aspect:

This slideshow requires JavaScript.

3 comments

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.