Questions about the AA-10 Alamo

Please tell me!

So positioning is the new rule in air combat.

Hardly a new rule… how many kills did the Harriers get in the Falklands war against Argentine fighters from the front?

Maybe some have problems. Max distances for AAMs are given at optimum height.
Launch aircraft deliver surplus energy, when flying near maximum speed with AAMs.
This in mind, a MiG-25 offers the best launch platform.
Opponents closes at max. possible speed. The best target would be a MiG-25 too.
All this without manouvering in straight line. The nominal range of a R-27 will be impressive. But the AAM has a limited lifetime after firing. ~ 1 minute, after that it is detonated by timer.
The size of the target does not really matter, when it comes to range. Mach 0,9 is Mach 0,9, flown by a fighter or bomber. The impressive datas are related to a non-manov. target and launch-plateform. The slightest manouvering eats into range.
Under non-manouv. conditions in optimum height, great closing speed, similar given for SU-27 by -Aerospacetech- and 0,9 kill-ratio, you can fire a R-27 from ~95 km distance.
In persuit it is down to 16 km.
At low level you can fire from ~20 km distance.
In persuit it is down to ~3,5 km.
If the AAM has to manouver against an avoiding target and you are not in 1 G condition, it will be less.
So much about theoretical and practical values for AAMs. Practical distances around 100 km will be achived with Ram-jet-booster in the future.
So positioning is the new rule in air combat. Which firing-envelope will you allow for your enemy and which one will be good for you.

You can think that all you like Garry, the truth is only the not-in-service R-27EM used a lofted profile.

Do you have more than your word to back this up?… Not a criticism of your word, just like some confirmation, as I have an article written by Mig that shows in a duel with a long range aircraft that the Alamo uses a lofted flight profile and will therefore arrive on target earlier than the enemies SARH missile. As it is MIG I dbout they will be talking about the Naval R-27s as the Su-33 got the nod well before this article was published.

A lofted profile is a software thing anyway, not a hardware thing, so any R-27 could be recoded to do it if they have one coded to do it. I really don’t understand why the EM model which is designed for low targets over sea clutter would sue a lofted profile as it is more likely chasing Harpoons rather than high flying or very long range targets.

The ET version is highly useful in tail-on engagements. The R-27 base version has a range of 35km head on, but tail on its only 18km, limited by the engine, not the seeker. The E models boost tail-on range considerably, to around 40-45km.

Except that the Flankers were the only aircraft carrying the long burn model Alamo and also the only aircraft carrying the IR versions of the Alamo too… unless you count the Yak-141.

Yet, the seeker head in reality has trouble exceeding 8-10km head-on against a head-on fighter class target.

Which would suggest inferiority to the sidewinder except that Hungarian pilots are trained to fire at 20km, as are Russian Fulcrum pilots, which suggests rough parity with Sidewinder seeker range and sensitivity performance. In a monsoon both missiles have seeker ranges measured in single or double figure metres. You need to be clear about the conditions before you suggest a range limitation. (One assumes 20km is in the conditions Hungarians and Russians expect to fight.)

To sumarize; even though in theory the head-on range of any AAM should be higher than in pursuit mode, in practice the opposite is true thanks to the limitations of the seeker.

To summarise the range figures given for all AAMs is generally kinematic rather than realistic combat ranges. AMRAAMs might fly 50km plus but are unlikely to be used at more than 20km as they rapidly lose effectiveness beyond this range against alerted targets. The same applies to any other AAM.

Modern propellant are better but the great increase in range comes from other factors :
– the structure around the solid propellant was made of steel. Nowadays, carbon with liner is much lighter
– the electronic used to be huge. In the first sparrows missiles, the electronics took more room in the body that the propellant. So think about less state of the art russian electronic …

The R-27 is modular. Which means the rocket booster, and the warhead/seeker section are seperate. We have seen enough pictures and drawings of both to so easily and visually conclude that the booster is so much larger than the seeker/warhead module.

Modern propellant are better but the great increase in range comes from other factors :
– the structure around the solid propellant was made of steel. Nowadays, carbon with liner is much lighter
– the electronic used to be huge. In the first sparrows missiles, the electronics took more room in the body that the propellant. So think about less state of the art russian electronic …

hasnt the alamo allready beat the aim-120 in the indo -us exer. at gwalior?

To sumarize; even though in theory the head-on range of any AAM should be higher than in pursuit mode, in practice the opposite is true thanks to the limitations of the seeker.

So why create the ET version at all? And why should any airforce buy this kit? What will the numbers be like in pursuit mode?

The ET version is highly useful in tail-on engagements. The R-27 base version has a range of 35km head on, but tail on its only 18km, limited by the engine, not the seeker. The E models boost tail-on range considerably, to around 40-45km.

The Su-27’s radar has trouble detecting much past 40km in tailchase against a fighter, so IR is a good seeker to choose for tail-on engagements. You’ll probably have a nice juicy afterburner or two, and locking on at 40-45km or so would be no problem. So- you would use R-27ER in head-on engagements, and R-27ET in tail-on ones.

Incidently, the same confusion affects R-73 range figures. The HEAD-ON range is quoted as often quoted as 30km, and certain Western analysts have spouted forth on how it has a great range advantage over AIM-9. Yet, the seeker head in reality has trouble exceeding 8-10km head-on against a head-on fighter class target. In tail-on engagements, the seeker range can increase substantially, but the missile’s achievable range will probably be more like 15km.

i think u need to weigh in the NEZ of the missile rather then absolute maximum kinematic range..

This means that R-27ET has a range of 66km, but only if the aircraft is detectable HEAD ON at 66km using the R-27ET seeker which is unlikely unless you are aiming at the sun

So why create the ET version at all? And why should any airforce buy this kit? :confused: What will the numbers be like in pursuit mode?

You can think that all you like Garry, the truth is only the not-in-service R-27EM used a lofted profile.

All basic R-27 models head directly for the target. Note that ONLY the radar homing versions use inertial + midcourse guidance. This was not some “killer idea” from the Russians but the only solution to their inability to get decent range from their radar/SARH seeker combination to match or hopefully outrange Sparrow.

The IR versions don’t have inertial/midcourse guidance, they are Lock-On-Before-Launch (LOBL) only. This means that R-27ET has a range of 66km, but only if the aircraft is detectable HEAD ON at 66km using the R-27ET seeker which is unlikely unless you are aiming at the sun 🙂

I see. All of you thanks!

So if one would choose a missile, one would choose the AA-10 Alamo in stead of the AA-12 Adder right?

Max range is not the most important thing with missiles.

The R-27s are all limited to 8g targets, whereas the R-77 can engage 12g targets.

Also when you launch an R-27, unless it is an IR version you need to keep closing with the target till impact. With the R-77 you can turn away any time you like (though once it is within 20km of its target and has its own lock you have a better chance for a kill).

The R-77 is also much lighter and it was designed from the outset to be carried internally… the grid fins fold flat along the missile to make for a very compact design.

There are IIR and IR as well as passive RH and longrange models of the R-77 in the pipeline. It will be a formidible weapon when fuly operational in its final R-77M form. (assuming it is not already ready).

So if one would choose a missile, one would choose the AA-10 Alamo in stead of the AA-12 Adder right?

Not engagement range, no. Kinematic range, yes.

So, against a relatively slow and docile target like a bomber, the missile, if fired from above, could reach and hit it at greater ranges?

The actual real engagement ranges, taken from an Su-27 combat employment manual, are:

Which realistically equate to the distance they should be fired (within the parameters listed) where the probability of a kill is relatively high.

In the same sence that a bullet from a rifle might kill at over 3km but effective range is a small fraction of that range depending upon the conditions.

No, the R-27 does NOT use a lofted profile. The R-27EM did, which is how its range increased.

According to my info the long range models of the R-27s all use lofted profiles. This feature plus the updated midcourse correction are given as advantages over the contemporary versions of the Sparrow.

Improvements to Rocket fuel performance since the R-27 entered service have been signficant. Look at the difference in performance between the R-33 and the R-37… roughly the same dimensions but large differences in weight and range. Perhaps that would better explain the increase in range for the R-27EM? Considering the EM is designed for low level over water targets is it really likely to use a lofted profile?

BTW could you post figures for the EM. I haven’t seen any numbers for this naval weapon.

Not engagement range, no. Kinematic range, yes.

So you guys are saying the R-27ER and R-27ET never had ranges beyond 100km?

No, the R-27 does NOT use a lofted profile. The R-27EM did, which is how its range increased.

The actual real engagement ranges, taken from an Su-27 combat employment manual, are:

Speed of Su-27 1100km/h
Target speed 900km/h
Head-on course
height 10,000m

R -27ER, R -27ET, R -27EP – 66 km.
R -27R – 35 km.
R -27T, R -27P – 30 km.

The R-77 range under the same conditions is about 50km.