The breakdown of the presented information and modus operandi can be found in Part II of this series, along with the broader analysis of the “new” AIM-54 Phoenix. I recommend checking it if you have not yet.
Rather than go into the details of every combination of parameters as I did in Part II, I will focus on some examples and then present tables useful to intuitively understand the impact of the various parameters.
As we know, manual loft is a simple technique that helps the missile to reach higher altitudes and, of course, it can be easily abused in DCS.
45,000ft
Let’s start at 45,000ft and a distance of 80nm. This is the highest and farthest set I tested, and the new AIM-54 already behaved well in this scenario.
A brief look at the speed chart reveals multiple interesting points:
- In primis, the first half of the chart shows how firing at supersonic speeds offers a visible help to the missile, but the effects of manual loft are not yet visible;
- Looking at the second part, after circa the 1-minute mark, we see how the manually lofted missile diverges from the standard curves. The reason is revealed in the next chart: altitude
Manual loft pushed the updated AIM-54 Phoenix more than 3km or 10,000ft higher than the standard launch, and over 3.6km or 12,000ft higher than the 2025 version. This is quite impressive indeed, and the altitude is then converted into energy, thus benefiting the terminal and impact speeds.
Speaking of numbers, the gain between the old AIM-54 and the new missile is M.3. If manual loft is involved, a 20° pitch up translates into a gain of M.6 over the old missile, and M.3 over the new one, hitting the target at the impressive speed of M2.73.
35,000ft
Let’s see how the Phoenix behaves at 35,000 ft and with the target at 60nm. The pitch angle from now on is 25°.
Compared to the 45,000ft scenario, we start to see the effects of manual loft. Above 13.5km in fact, the altitude becomes less of a factor, given the properties of the atmosphere up there.
Looking at the speed chart, the curve representing the manual launch at M1.2 is consistently better than any other scenario. So far, nothing particularly surprising.
25,000ft
Down to 7.6km or 25,000ft, the altitude starts to become a factor. Let’s have a look at two examples: 80nm and 40nm.
Starting from the farthest, the impact of the 25° pitch up is massive. Both the subsonic and the supersonic employment benefit greatly and are the top performers by a meaningful margin. Compared to the standard employment, the Phoenix launched at subsonic speed gain M.4 at activation, and M.3 at impact. The supersonic launch gains M.6 at terminal and M.41. Not only that, but the average speed is also higher, resulting in a flight time 14s shorter, for a total of 02:38. This is relevant, as missiles that take a very long time to connect may run out of battery.
A point worth noting is that the performance is seriously improved even when the missile is launched at subsonic speeds. Outside airquake scenarios, in fact, fuel is a fundamental variable, and reaching speeds faster than the speed of sound usually requires reheat and a hefty amount of fuel. So, ensuring good performance whilst saving fuel is often a no-brainer deal.
At 40nm and 25,000ft, the curve changes again. It is now triangular, as the cruising phase is quite limited. Therefore, the Phoenix reaches the apex of the envelope and quickly dives onto the target.
In terms of performance, the gain is once again important, and in the neighbourhood of M.4 for the supersonic employment, and M.3 for the subsonic one.
15,000ft
Moving to 15,000ft, the impact of the atmosphere becomes greater and greater. Employing against a target at 60nm at such a low altitude should be avoided, but let’s see whether manual loft can change the performance of the new Phoenix enough to make it viable.
Starting, as usual, from the speed chart, we immediately spot something we like: thanks to manual loft, the Phoenix is not losing as much speed as it would otherwise do during the cruise phase. Truth be told, the old AIM-54 follows a similar pattern, but its cruise speed is drastically lower. Looking at the altitude chart, we immediately have an explanation for such a phenomenon. Thanks to the 25° pitch up, the new missile turns from the lowest to the highest.
Unfortunately, even the best impact speed is too low to make the Phoenix a real threat, falling short of M1.2, with a terminal speed of M1.8.
Let’s have a look at the 40nm test, once again at 4.5 km. If you are wondering if the Phoenix is now a real threat, the answer is still no, but manual loft makes it more manageable. In fact, the top performer, which is the supersonic employment, is flying close to M2 when activated, and it impacts at M1.25. Not great, but definitely better than arriving subsonic.
Once again, the speed charts show the effects of reaching higher altitudes. Opening a brief parenthesis here, if you have noticed, the Phoenix’s envelope falls into three brackets after the initial climb:
- At long ranges and high altitudes, a cruising phase is observable where the speed is fairly flat and constant. The speed slightly increases, or it is fairly constant, at the beginning of the dive. This appears to be the most effective envelope.
AIM-54 Curves – High/Fast. - If the Phoenix does not reach the same high altitude or the target is closer, the curve resembles a triangle. The cruise section is either missing or there is a fairly constant, and usually contained, loss of energy.
AIM-54 Curves – Constant energy loss. - Lastly, if the AIM-54 really struggles, the curve appears similar to an exponential function with the exponent smaller than 1. The energy is lost more or less rapidly after the initial peak, resulting in a floppy terminal behaviour.
AIM-54 Curves – Energy-starved Phoenix.
Back to the same test, 40nm at 15,000ft, if we focus on the new Phoenix when launched at M1.2, we see both the second and third types of behaviour just mentioned.
5,000ft
Last set of data, 1.5km or 5,000ft. Although I collected data against targets flying at 50nm and 40nm, those are a bit of extreme situations. Let’s see something more realistic. Speaking of which, although I gathered the result at M1.2 for consistency’s sake, this is quite a difficult speed to reach, unless the Tomcat is almost clean. Keep that in mind.
The results collected at 30nm are very intriguing. Starting with the speeds, we observe the usual great benefit provided by manual loft. Is it enough to make the Phoenix a threat? Well, not really. In the best situation possible, the missile reaches the acceptable speed of M1.67, at least compared to the old missile, showing a solid M.55 increase. However, and this is worth noting, none of the tests conducted impacted at supersonic speed.
Curiously, the AIM-54s launched whilst pitching up did reach 30,000ft. However, they had to fly through the thickest part of the atmosphere and for such a long time that, eventually, it did not matter much. This is one of the few examples where, no matter the altitude the Phoenix touched, the ultimate effect is not particularly thrilling.
Last set, same altitude and a range of 20nm. Will manual loft have an influential effect on the missile performance at such a low altitude and short range? Let’s see.
In terms of speed, the increase is neat, almost double the performance of the old, non-lofting, AIM-54. Compared to the new Phoenix launched wings level, the gain is only a minor M.17, resulting in an impact speed of M1.21 and an activation speed of M2.24. On paper, this increase is not enough to make the missile a threat against fighters, but makes the Phoenix a solid choice against less manoeuvrable aircraft. To reiterate, the old AIM-54 impacted at M.68, the new version at M1.04, which becomes M1.21 when manually lofted.
The additional energy becomes exponentially more relevant if the range decreases and sets closer to 7nm-12nm, which are in the neighbourhood of the rocket motor running out of juice, and therefore, it is where the Phoenix has maximum energy.
Comparison Tables & Conclusions
Let’s check the familiar recap tables from the previous discussion, and compare them to the new ones.
Despite all the green, the reality is different. Even an important performance gain of 20% becomes almost irrelevant if the base value is subsonic. The reality is that manual loft, besides a couple of scenarios, reinforces the already notable performance of the Phoenix and extends and widens the performance boundaries, increasing the employment flexibility. However, it does not reverse the status quo, making the AIM-54 a threat where it never was.
This second set of tables clarifies this point: each value is the upper limit of M.5. Ergo, “2.5” means that the related speed fell between M2 and M2.5. “SS” stands for Subsonic.
Now, an impact speed between M1.5 and M2 is not necessarily bad, but it offers a wide escape margin to the target. For instance, by diving, turning cold and unloading, or executing the nemesis of every DCS missile: the Split-S. As usual, it all comes down to situational awareness, proficiency, and competence: those parameters decide whether a missile has any chance to connect or it is doomed to become a sinking brick.
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