R-27 cannot intercept supersonic targets

[Max1mus]

While most people focus on kinematics or chaff rejection when it comes to their missile biases, this topic is different. Its known that R-27ER, especially if not supported correctly, will be spoofed easily with chaff. This is NOT what this post is about

 

The missile seems to have a huge problem with intercepting very fast bandits (mach 1.5+) if they are even slightly suggesting to be flanking.

 

Here is one example:

 

https://i.imgur.com/N5kfSTX.png

 

The missile will, despite being supported while diving and keeping the wings level, pass the aircraft at mach 1.9 (0.5 or so faster than the F-15), but not explode. No chaff was dropped and it did not go for chaff.

 

Another example:

 

http://www.mediafire.com/file/cbykpijdcmpugbe/High_1+%282%29.acmi

 

This tacview shows an ER that does NOT go for chaff or loose lock pass the still hot aircraft despite having over 1 mach more speed. This will happen 100% of the time under these parameters. Giving the missile a PK of 0% against a nonmaneuvering target despite it having the energy to do so under these parameters.

 

This is easily reproducable in single and multiplayer.

 

Is this intended behaviour? Its been an issue for at least months.

Edited July 8, 2019 by Max1mus

[BlackPixxel]

I also had such a situation yesterday.

ER fired at head on bandit. The bandit (F-15) starts to do a gentle turn with 1.5 to 2.5 g and pulls a max of 3.9 g for a very short moment. Still enough to make the ER that has lots of energy miss. No chaffs + look up against the clear sky.

 

 

I may as well take R-27Rs, they have the same chance of hitting the bandit (0 %) and they also give the bandit a launch warning, but at least my plane will be lighter and faster with them.

[Drona]

Have you guys considered lag? Which server was this on?

[FoxAlfa]

Just to save you guys approx 25 pages of conversation.

 

https://forums.eagle.ru/showpost.php?p=3887106&postcount=263

 

But I think it would be beneficial if you pushed ED to move up the R-27 family update.

[Airhunter]

Both the 27's and 77's need updating. I hope this comes soon.

[pepin1234]

Don’t waste your time guys. Is obvious that will remain the same. Go play Cold War 60s... take a research in the forum and you will see. Be smart...

[3WA]

Ughh. So MUCH needs to be corrected in this sim.

 

 

We don't need more planes, we need fixes and corrections to the General World.

[GGTharos]

I don't think this is an R-27 issue.

[Exorcet]

Weird, I haven't encountered this. I expect I would have given that I spent a bit of time in a 2 v 4 F-14 vs MiG-29 mission I made. The MiG's were armed with ER's against my 7M's. My wingman would die repeatedly which would often leave me alone against 4 MiG's and I'd usually die to an ER or 73. Does this not impact the AI?

[GGTharos]

The AI doesn't abuse the game in creative ways, rather, it can't learn. The vulnerability is against supersonic aircraft ... think M2KCs getting fast and high and barrel rolling everything under the sun.

 

 

Any aircraft that can gain enough speed can do it. I imagine the issue is two-fold. One is latency, which is always an issue - the other, I believe the maneuver parameters on the R-27s are still quite low.

[Exorcet]

That's one of the things that made me wonder. I was trying to go supersonic to make up for the energy advantage of the ER's over the 7M, yet it didn't grant me invulnerability. I might not have been going fast enough.

 

 

Anyway there is clearly an issue looking at the link FoxAlfa posted, so you're probably right on why this is happening.

[TaxDollarsAtWork]

I have been having these same issues as well how long until ED gets the CFD for the R-27 family?

[nighthawk2174]

I know these numbers probably won't be used but I decided to run a CFD run on the AA10A and AA10B. I actually did these quite a few months ago for a missile mod the group I fly with uses but never quite posted them.

 

CD0 - Drag coeficent at 0° alpha - AA-10A

 

 

 

 

CD0 - Drag coeficent at 0° alpha - AA-10B

 

 

 

 

AA-10A Modded DCS VS "That other Sim"

 

 

 

 

AA-10A UnModded DCS VS "That other Sim"

 

 

 

 

Edited July 28, 2019 by nighthawk2174

[Max1mus]

I know these numbers probably won't be used but I decided to run a CFD run on the AA10A and AA10B. I actually did these quite a few months ago for a missile mod the group I fly with uses but never quite posted them.

 

CD0 - Drag coeficent at 0° alpha - AA-10A

 

 

 

 

CD0 - Drag coeficent at 0° alpha - AA-10B

 

 

 

 

AA-10A Modded DCS VS "That other Sim"

 

 

 

 

AA-10A UnModded DCS VS "That other Sim"

 

 

 

 

This thread is not about kinematics. The issue seems to be fox1 guidance and that for whatever reason at specific ranges the ER refuses to turn onto a target and ends up missing it at very close range (despite clearly having the energy to do it). When it comes to speed and range i find it hard to believe that EDs (apparently based on real RuAf docs) information is inferior to public research based on assumptions.

[GGTharos]

It actually might have to do with kinematics, just not the ones captured here. The lift coefficients for the R-27s are very low (IIRC), which makes things worse in thinner air.

[nighthawk2174]

^ this

Edited August 2, 2019 by nighthawk2174

[pepin1234]

It actually might have to do with kinematics, just not the ones captured here. The lift coefficients for the R-27s are very low (IIRC), which makes things worse in thinner air.

 

can you post your formula to calculate the R-27 lift. Doesn't show to be applied to certain missiles you support in other threads https://forums.eagle.ru/showpost.php?p=3990003&postcount=115

[vanir]

Since I'm a westerner that prefers flying Russian birds for variety, growing up in the cold war made me so familiar with NATO aircraft I just prefer losing myself in Russian ones for a change.

But it does really get up my nose how badly the Russian air intercept missiles perform, definitely biased against. As a science enthusiast I just find it academically unsound, personally. The Russians had phased array in a front line fighter type in '91, they're not deficient and are just as capable of reading the same physics books western scientists read. So what gives?

[JunMcKill]

can you post your formula to calculate the R-27 lift. Doesn't show to be applied to certain missiles you support in other threads https://forums.eagle.ru/showpost.php?p=3990003&postcount=115

 

Formula:

 

Any_western_thing Pk = any_weight_speed_distance * 100%

Russian_BS Pk= (weight + distance / speed) * 0.00

 

Welcome to DCS!

 

:D

Edited August 2, 2019 by JunMcKill

[nighthawk2174]

@Pepin1234

[GGTharos]

No Pepin, I cannot ... I have an entire sheet of formulas for replicating the (old) behavior in DCS, but in the end they're not THAT important: you need to change the Cy_* values to be larger than they are right now.

 

 

 

can you post your formula to calculate the R-27 lift. Doesn't show to be applied to certain missiles you support in other threads https://forums.eagle.ru/showpost.php?p=3990003&postcount=115

[TaxDollarsAtWork]

https://streamable.com/elvvg Supersonic or not it seems R-27s need their guidance looked at

[Oceandar]

IIRC Chizch said the weapon team will be looking at R-27 guidance just like they did on AIM-7. They're currently busy with hornet and viper weapons. Oh.... well....

[Airhunter]

To be fair, the real R-27's combat record isn't exactle great. A lot were duds or never hit the target.

[Falcon_S]

To be fair, the real R-27's combat record isn't exactle great. A lot were duds or never hit the target.

 

Where they are used in real combat, Eritrean-Ethiopian War? If that amount of fired R-27's is enough to say that they are so bad then judging by Yemeni Civil War (2015–present) and Houtis shots they are very nasty ;)