R-27ER update?

I heard in an interview by ralfidude with the guy doing the Phoenix modeling for HB and he said that ED defines rmax as where the missile stalls out. But in the missile newsletter I think they mentioned that the interception velocity for an AIM-7 should be 700kmh, don’t know if that meant at rmax or not and if that even hints at tweaking drag curves to get a higher speed at rmax than just stalling out for all missiles.

Rmax is the max range the missile has under ideal circumstances on a non maneuvering target. On what altitude that is is and what speed the launch platform has is unknown to me.

Again this is a complex topic and will vary greatly from missile to missile and from airforce to airforce what they use. And my question was more what do the graphs for the ER, posted earlier, define as Rmax? If at all; not what rmax is but what they define the missile is able to do at rmax.

No such information is offered unfortunately. There is a sort of fly-out graph (missile time-to-target after launch), but it's difficult to interpret.

So what can we expect with regards to seeker improvements? Better CM resistance?

 

Again this is a complex topic and will vary greatly from missile to missile and from airforce to airforce what they use. And my question was more what do the graphs for the ER, posted earlier, define as Rmax? If at all; not what rmax is but what they define the missile is able to do at rmax.

No one knows if that is the Rmax, I consider that the chart marks the distance where the missile flight profile have a good Pk and not the Rmax. In this case, the chart say that a missile launched at 1100 km/h speed and 10km high, can kill at a non manueverable aircraft at 70 km away. Anyway, is a simple chart for weapons deployment in the SU-27SK, not a complete study of the missile.

This is the manufacturer data:

http://eng.ktrv.ru/production/military_production/air-to-air_missiles/r-27r1_-_r-27er1.html

All missiles have always had PN (otherwise they wouldn't hit anything). What they have done is change the algorithm to APN together with N varied by range.

The question is when, or if, the R/T/ER/ET family get the new APN similar to the Aim7, 120 and 77 now have.

Chizh said (According to what I understood) that they won't be making changes to them.

November 2 newsletter

That's great, and while I'm sure it'll acquire all of that if it hasn't already, it's not getting APN - that's what I meant.

This whole thread reads like, "hey, please make missile x perform better," instead of, "Hey, please make missile x have more realistic performance."

The latter requires documentation or other evidence, instead of, "I feel..."

Without going into specifics the presumption is that APN modelling is more realistic than PN modelling. Hence the question as to why the R27 family has been omitted from getting such an update.

You can see it when you test the missiles. The 27R will pull an exaggerated manoeuvre that completely drains it's energy. That might be somewhat less with APN modelling. Similar to how the 77 has benefited and probably become more realistic.

We can compare all we want with other missiles, the bottom line is R-27r is useless as in the game.

Even head-on a slow (0.5 mach) target it will run out off steam in 9km (~5.5 mil) or less... I don't think such a missile would pass any Military trial... it is simply bleeding too much energy

https://forums.eagle.ru/attachment.php?attachmentid=201825&stc=1&d=1547151964

https://forums.eagle.ru/attachment.php?attachmentid=201826&stc=1&d=1547151964

You're shooting low to high, your missile has reasonable speed at the range of the target but its eaten chaff. I think your expectations might be a little higher than they ought to be for the aerodynamics, but it should have guided.

https://forums.eagle.ru/attachment.php?attachmentid=37859

it's the engagement envelope (range) of the missile on the head-on (left axis), side on (top axis) and escaping (right axis) target.

the full line is for the target traveling at 1100 km/h and the dotted line is for the target traveling at 900 km/h.

the blobs corresponding to the engagement altitude of 1km, 5km, 10km.

So per example, the range against a target traveling 900 km/h at 5km equal altitude head-on should be around 38km and for the same target side on around 17km.

Wrong missile. I'm quite familiar with these DLZs. Cut in half for R-27R.

You're shooting low to high, your missile has reasonable speed at the range of the target but its eaten chaff. I think your expectations might be a little higher than they ought to be for the aerodynamics, but it should have guided.

Maybe yours are too low and that is the point of the whole thread.

Using the graph you provided and I know it is for the R-27ER and not the R-27R, but keep in mind the target is much slower than 900km/h, the target parameters are at the red dot and well within any envelope.

https://forums.eagle.ru/attachment.php?attachmentid=201829&stc=1&d=1547155780

Wrong missile. I'm quite familiar with these DLZs. Cut in half for R-27R.

Even if we cut them in half, but most sources claim 25-35% difference in range, according to the graph the range would be 14km, and the missile is fired from 9km well within the envelope and almost dead by 3 km from target.

Nobody is saying the R-27 is a wonder weapon, but that is underperforming due to faulty guidance. I feel that the missile is kinematically correct and would reach correct ranges if it doesn't maneuver, but the current guidance cause too big of G-loads and speed bleeds.

Both R-27ER and R-27R are heavily impacted by it, but it wasn't that noticeable before since all the missiles used the same algorithm.

It's at M1.6 with a 9km shot ... at this point it won't be slowing down quite as fast. As for guidance, I don't really know what to tell you, ED seems to have made their choice, but again, that's my interpretation.

https://forums.eagle.ru/showpost.php?p=3722103&postcount=6375

https://forums.eagle.ru/showpost.php?p=3723317&postcount=6391

It's not going to happen...

It sounds like Chizh is saying the real R-27 has no type of PN guidance

It has, otherwise it wouldn't hit anything. Chizh said there is no variable PN coefficient in R-27 guidance logic.

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TBH I'm quite surprised.

Seems like a lot is being lost in translation. But say if it is true...

How about older Aim-7 variants like E and F versions, do they have these features IRL? If so, R-27 seems like a very flawed missile in comparison...

Maybe the Soviets invented the 27ER to try ”counter” this no variable pn flaw? From what I have read the R-27R suffered from short legs maybe it was partially due to missile navigation flaws?

Maybe the Soviets never felt it was needed, if they assumed the R-27 series were to be used as bomber killers only and that large BVR missiles had no place in fighter vs fighter combat. Or they were just going for simplicity. I'm just speculating here.

Still, even if it's realistic (Actually, especially if it's realistic) the fact were stuck with the poor performance of these missiles is disheartening.