R-77's Not tracking Properly With J-11A

I don't think anyone was claiming the R-27 missiles are poor as such.

Actually it is more maneuverable and less draggy at high speed

Just wanted to add to this. Lattice fins are more maneuverable low subsonic and high supersonic speeds. Low subsonic drag is equivalent to traditional fins, high supersonic drag is lower than traditional fins. But at transonic speeds and low supersonic speeds, flow through the lattice is choked resulting in a drag force much higher than traditional fins.

SinusoidDelta, after I reread what I wrote, I see I've missed "also" (ups) in my sentance... thank you for writing your explanation, making it more clear for everyone.

Actually it is more maneuverable and less draggy at high speed ;)

Limit of my knowledge here, but I get the impression that at high speed you're going to run into a g or AoA limit way before you can consider which fin does something faster.

Indeed :) ... If we look at the russian SAHR missiles, with R23 introduction it was in front of AIM7E (Russians got AIM7E and made a copy - R25 which did not perform as well as R23 which used monopulse homing head) and when 7F came out, R24 INS link was answer to the range increase.

... but it was never shown to be a successful contender. Not that 7F was stellar.

With introduction of 7M the US was again on pair. Basing on this history, it's only logical that R27 would not be a step backwards ... and we must also not forget that R27 now is not the same as R27 in pre '90s as well... if Russian could make R24, R73... it is a naive to think that R27 is a flop :)

R-27R disappointment vs 7M/MH is expressed by the VVS, not me :) OTOH, good luck finding my reference again. :(

Just wanted to add to this. Lattice fins are more maneuverable low subsonic and high supersonic speeds. Low subsonic drag is equivalent to traditional fins, high supersonic drag is lower than traditional fins. But at transonic speeds and low supersonic speeds, flow through the lattice is choked resulting in a drag force much higher than traditional fins.

This is my understanding as well. I am no expert on the subject but it strikes me as reasonable to expect that this contributes to a missile that is immensely agile at high speed, but generally less able to retain energy once its fuel reserves are exhausted - especially against a maneuvering target (induced drag etc). The current state of DCS drag physics and missile flight profiling probably only serves to exaggerate this behaviour.

I'd like to reiterate to Fri13 that literally nobody is attempting to deride any Russian missiles here. Russian rocketry is highly regarded for good reason. My guess is that the original R77 simply was not designed to be the longest spear in the Fulcrum/Flanker arsenal, but to rather act as an agile fire-and-forget bridge between the R73 and long burn R27 variants. This looks set to change when izdeliye 180 comes around (and may have already done so to some degree with R-77-1).

Limit of my knowledge here, but I get the impression that at high speed you're going to run into a g or AoA limit way before you can consider which fin does something faster.

My thinking regarding lattice fins is the increased drag penalty lies directly in the most common area of the launch envelope. To have an advantage the missile needs to be launched from M1.2+ Otherwise it has to accelerate through the choked flow to high supersonic speeds negating the benefits.

This fits with what I've always suspected - that the VKS essentially hasn't bothered with the R-77, with the exception of a very small number used on Su-35's deployed to Syria, although those could have been export marketing essentially; and are probably waiting for the Izdeliye 180 / K-77M which will arm the T-50 / "Su-57" when it eventually enters service.

The R-77 was formally introduced to operational service in 1994, but at the time the Russian economy was in a bad shape. So there was no money to purchase the weapon, nor did they have any aircraft compatible with it, since the new types meant to employ it(such as MiG-29M/K, Su-27M and MiG-31M) were cancelled. So they would not only need the cash to buy the actual missile, but also for upgrading their existing fleet of aircraft to use it. So the R-77(RVV-AE) was only produced for export orders in the same way(and as part of the armament) of e.g. the Su-30MK.

The version seen on Su-35s in Syria is the new updated RVV-SD(or domestic version of it) which has the same aerodynamic configuration as the RVV-AE including the lattice fins, but is a little longer and heavier, has better range(due to a bigger motor) and updated electronics. IIRC this was only put into serial production in ~ 2015 and is currently in the process of being inducted with the Russian airforce.

A little off topic but is the RVV-SD integrated with the Su35 only or can it be fitted to the Su27S or upgraded Su27SM, Su30SM etc?

A little off topic but is the RVV-SD integrated with the Su35 only or can it be fitted to the Su27S or upgraded Su27SM, Su30SM etc?

Well it can be integrated with any of them provided that the necessary modifications are made for it :) .

But I don't know which types this concerns currently - IIRC the reason why e.g. the Su-30SM were initially seen carrying only the R-27R in Syria, was that the RVV-SD(or "item 170-1") had not yet been integrated with the WCS.

... but it was never shown to be a successful contender. Not that 7F was stellar.

As you well know, statistics is always a complicated topic :)

If my mind is not cheating on me, I think Russian scored 2 kills with R24R over the border into Pakistan. How many did they fired w/o success, etc. or what is actual tailly, that is hard to get any data on.

R-27R disappointment vs 7M/MH is expressed by the VVS, not me :) OTOH, good luck finding my reference again. :(

Well if you could find the reference that would be nice.

However we must not forget that R and ER versions were planned from start. ER did not happen because of poor performance of R. The whole point of R27 was to have modular design. The shorter ranged R is tactically analogues to R3R and it was never meant for BVR exchange.

My thinking regarding lattice fins is the increased drag penalty lies directly in the most common area of the launch envelope. To have an advantage the missile needs to be launched from M1.2+ Otherwise it has to accelerate through the choked flow to high supersonic speeds negating the benefits.

A very worthy hypothesis! I suppose the x-factor is that the R77 also has those more conventional mid-body wings (strakes?) - how they affect things in terms of drag I have no idea. As I say though, I have a strong suspicion that the original R77 was designed more as a very nimble pre-merge missile than a truly long spear at BVR ranges (ala R27ER). The design seems to be evolving into a direct competitor to late model AIM120, MICA, Meteor etc. now.

A very worthy hypothesis! I suppose the x-factor is that the R77 also has those more conventional mid-body wings (strakes?) - how they affect things in terms of drag I have no idea. As I say though, I have a strong suspicion that the original R77 was designed more as a very nimble pre-merge missile than a truly long spear at BVR ranges (ala R27ER). The design seems to be evolving into a direct competitor to late model AIM120, MICA, Meteor etc. now.

Interesting theory, and it would make sense. R-27ER, R-77 & R-73 would make a powerful combination.

Interesting theory, and it would make sense. R-27ER, R-77 & R-73 would make a powerful combination.

I suspect that was the idea. R27ER forces an alerted opponent to start defending (and in turn bleeding energy) early in the engagement, R27ET is there for seeker-head diversity and opportunistic sneak attacks. R77 and 73 were/are there to make the inescapable kill shots at closer range.

I suspect that was the idea. R27ER forces an alerted opponent to start defending (and in turn bleeding energy) early in the engagement, R27ET is there for seeker-head diversity and opportunistic sneak attacks. R77 and 73 were/are there to make the inescapable kill shots at closer range.

You seem to forget that the guy supporting the ER will have an AMRAAM inbound, and so will his wingman, so they will eventually have to leave their SARHs and defend or risk getting a slammer in their faces. And the SARH platform is limited to engaging only one at a time where as the ARH platform is not.

I suspect that the R-77 was a first edition that needed improvement. But because the soviet union and economy had collapsed, that didn't happen.

You seem to forget that the guy supporting the ER will have an AMRAAM inbound, and so will his wingman, so they will eventually have to leave their SARHs and defend or risk getting a slammer in their faces. And the SARH platform is limited to engaging only one at a time where as the ARH platform is not.

 

I suspect that the R-77 was a first edition that needed improvement. But because the soviet union and economy had collapsed, that didn't happen.

No didn't forget that at all - even an AMRAAM equipped pilot may frequently see fit to shoot a lower pK long distance shot primarily for the defensive response it elicits. I suspect the long burn R27 has an important role to play there.

I actually agree with you more broadly though - if the Russians had an "American" sized budget from the late 80's up until now I also doubt they'd be using the same missiles. I suspect you'd be looking at a more developed suite of radar and IR R77 derivatives instead of R27, with something like izdeliye 300 in lieu of the R73/74 and a smattering of R37/KS172 type weapons here and there as well. Alas, budgetary constraints were what they were, so they "pimped out" their existing weapons instead ;-)

It is very much not just a drag issue, the guidance is completely borked. All missiles in game, IR/RF, use LOS-rate PN. Radar guided missiles should be taking into account range/range-rate, angle/angle-rate, altitude, target accelaration, target maneuvers and so on, influencing the guidance response. INS is not modelled for RF guided missiles, when they loose lock they stop pulling any Gs and just fly straight. Lofting isn't properly implemented and just kills all the missile's speed instead of extending the range.

 

All this combined with the drag, CCM issues, netcode/proximity fuse issues makes ALL missiles a lot less effective than they should be, making for unrealistic BVR dynamics.

+1

Absolute true. PLS BigNewy, tell ED they need to correct all these mentioned above. We dont want to endup with every possible jet in DCS but still throwing only dumb wooden sticks on each other. Only because of ... we all know.

In the space of time since this year and a half old thread was posted, ED have updated proportional navigation. :thumbup: You can also configure lofting on AAMs in the F/A-18C. No one's saying it's perfect or anything, but you can see some tangible progress.

One of the users on this board, Ironhand, has done a comparison video showing the changes, you can find it here.

https://forums.eagle.ru/showpost.php?p=3639527&postcount=1