R-27ER update?

[AnarchyZG]

If those old R-24Ts (40 years ago!) can lock F-15s head on with burners off, then modern ones would make F-35 pilots sweat bullets...

[SgtPappy]

This makes zero sense, because there are cases where the side to side distance is bigger than the range. But the range to the target will always be equal or larger than the side to side range.

 

I think we are saying the same thing but interpreting each others' words differently - nowhere in the chart is the magnitude of the y-value greater than the 0 deg. aspect x-value range (i.e. head-on), and even if it was, per nighthawk's post (quoted below), the RCS might be big enough to the side that the seeker can pick it up and the missile kinematic range is long enough to reach it.

 

Just take any point on the plots - standard x and y - and calculate the resulting vector length. The longest length I got was 22.6 nm at 40kft (x = ~15nm and y ~ 17nm), about 45 deg. aspect. This is almost the same as the HO range of 22 nm - a difference small enough that can be attributed to my error in reading. Also easily explained by nighthawk's RCS post.

 

To me this graph works exactly the same way as the R-27 chart. It just uses very confusing axis labels. Look how similar the overall shape of the top right chart is to the R-27 chart.

 

Agreed - this is indeed what I mean. I think the axes on the AIM-7 plot plus the fact that the launch envelope takes RCS AND kinematic range (whatever is smaller of the two) into account already combine to make it confusing.

 

The top left chart obviously has an error, because the launch range for a head on engagement co altitude at 500ft is 16nm in the bottom left chart not 20nm as in the top left chart.

 

 

Why can't the bottom chart be wrong? Although I do agree they are inconsistent. The way I was interpreting the bottom two plots is essentially the xz plane while the top two are the xy plane envelopes but maybe someone can correct me.

 

 

The increase in side range could easily be due to RCS:

 

Note how at the ~50° degree's left and right from the nose the RCS is rather quite large. Now we don't know the exact aircraft and RCS used so we can't say for certain exactly how the RCS varied, but the difference in range in the sides is not a lot over the head on range.

 

Where did you find these? I could not find these images in all my 5 minutes of googling! :P

Edited March 3, 2020 by SgtPappy
grammar, spelling

[Ironhand]

This makes zero sense, because there are cases where the side to side distance is bigger than the range. But the range to the target will always be equal or larger than the side to side range.

My error. Range is simply how far down range you are from the nose-to-nose. Thought of that way, even the top right chart is accurate. 10 nm dowrange and 20 nm to the right or left leaves a range to target of 22.36 nm.

 

 

 

No, the text in my photo is refering to the missile components that are standing behind the text, not for the open seeker in the front.

 

No, it's labeling both what is in the foreground and background.

[BlackPixxel]

No, it's labeling both what is in the foreground and background.

 

This is impossible, because the complete seeker section is already standing on the left position in the background.

It would mean that the complete RF section of the R-27R seeker behind the antenna is used for "aerodynamic control".

It would also mean that the most rear part of the R-27R seeker is the homing head of the 5V27D missile.

 

Where the text says "Inertially semiactive radio location head" there is a complete seeker head (the complete head that can be seen open in the picture, but with the case+radome).

Where the text says "Block of aerodynamic control" there is the middle section of the missile with the canard controlls.

Where the text shows the next semiactive homing head you see a seeker of a different missile.

 

The open seeker head is just placed in front of the arrangement, with the mounts being exactly in the middle. The text is not describing what is laying in front.

[Fri13]

I would like to request you to read more carefully and please stop making assumptions from my words.

 

I am trying to have a proper conversation with you and everyone else here but for some reason you put words into my mouth and then continue to do so.

 

Stop putting your words to my mouth. Just STOP!

 

 

Once again, all I said is that the range on the graph matches at 60 deg. aspect compared to the 0 deg aspect range that is also on that graph. That is literally it. In fact, I'll break it down further:

 

In fact, I explained it to you that I don't deny the math. Read very carefully!

 

 

8^2 + 20^2 = 21.5 and 21.5 nm is close to 22 nm. Take just that sentence and tell me where in that equation it says "Launch at 20 nmi and all is fine".

 

Because your claim is that pilots do not need to know nothing about kinematic capabilities of the missiles or anything about seeker capabilities as only thing they would need to know is "21.5 nmi and you are always good to shoot!". That because you said specifically that it is meant to be simple "no math needed" graph. So you don't even need that graph as you can just state it always "at 21.5 nmi or closer you are free to shoot" kind information.

 

Nothing about real life Pk, nothing about true range... I never once said anything at all about whether the missile would hit. It was a super simple comparison. Now you're berating me for whatever reason.

 

Yes, I said you made it for super simple comparison that I very clearly pointed it out to you. Then you start twisting my words and attack at me because you can't withstand the fact that you made it super simple "Pilots, always know that you need to be at 21.5 nmi or closer and you are good to shoot!".

 

I do not appreciate it.

 

Yes you do.

 

I agree. The graphs show two different contexts so we can't compare the AIM-7 to the R-27 here.

 

Good, now you are getting it. WE CAN NOT COMPARE THEM!

 

The PDF I linked appears to take into account both RCS and aerodynamic range as stated before.

 

Yes, mixing everything to one batch without any valid information that what is the context of anything.

 

If it was just RCS, the plot would be larger in range at the rear aspect because the RCS would increase.

 

Again, the graphic doesn't make sense because it is mixing multiple things together that defies specific values.

 

But that isn't the case so then aerodynamic range starts to become the limit. See my graphic below.

 

As I have explained, it is mixing multiple variables to one graphic that doesn't make sense as is, but lack of context of the all pages that is explaining all the parameters etc is missing.

 

The envelope is only where the solid lines are. The dashed lines are too far for either the seeker or the missile itself. This is what I believe the graph is telling us (and yes this is a best guess so please don't start concluding that I'm saying this is 100% correct or anything).

 

 

If you look my graph, I specifically already included all that....

https://forums.eagle.ru/showpost.php?p=4230207&postcount=329

 

So please be more carefully what you are claiming.

[Fri13]

I scanned ahead and don’t think anyone has given you an explanation yet.

 

In the top two AIM-7 charts, range is distance between the two aircraft. Distance, on the other hand, is how far to the right or left of a nose-to-nose encounter you are. So in the top left chart, if you are 6 nm to the right or left of the target, you can launch when the range closes to 18 nm etc. That’s the only way the top 2 charts make any sense.

 

That is just only thing that could make any sense. But still the graphic is little odd for its purpose, like it could very well be just split half so upper part is 40kft and bottom part would be sea-level. So you combine two graphics to one and you get better understanding the change between:

 

[Fri13]

The increase in side range could easily be due to RCS:

 

 

Note how at the ~50° degree's left and right from the nose the RCS is rather quite large. Now we don't know the exact aircraft and RCS used so we can't say for certain exactly how the RCS varied, but the difference in range in the sides is not a lot over the head on range.

 

-Note the exact apparent RCS IIRC is also dependent on the frequency of the radar hitting it as well.

 

Yes, that was my take as well for it. That target has larger RCS at the front angle than straight forward. But considering that if you combine the kinematic change of hitting non-maneuvering target at X range, with the seeker head sensitivity and capability to track a 2m^2 target, then you might never have big variation in frontal hemisphere launch like you have otherwise at straight 90 degree and further where kinematic limitation grows.

 

So the AIM-7 graphic needs to be read that front hemisphere is seeker+aerodynamically limited, while rear hemisphere is purely aerodynamically limited in those specific altitudes and target+launch speeds.

 

And that of course assumes that pilot/WSO is using the proper radar modes to engage the target, etc.

[SgtPappy]

Stop putting your words to my mouth. Just STOP!

 

If we both feel this way can we both just apologize and be done with it? It's clear that we are misinterpreting each other.

 

In fact, I explained it to you that I don't deny the math. Read very carefully!

 

Actually this is all you commented on my math so forgive me - but surely you can see how your response confused me:

 

So your evidence is: "Just launch at 20 nmi range and you always hit the target regardless of anything". No need for any graphics, no need to train the pilots for anything about the missiles, radars or flying, just tell them to get to 20 nmi range with the AIM-7 and launch it.

 

 

Because your claim is that pilots do not need to know nothing about kinematic capabilities of the missiles or anything about seeker capabilities as only thing they would need to know is "21.5 nmi and you are always good to shoot!". That because you said specifically that it is meant to be simple "no math needed" graph. So you don't even need that graph as you can just state it always "at 21.5 nmi or closer you are free to shoot" kind information.

 

I can see how that might have been picked up from what I wrote. I apologize, this was not my intention. I only meant to show that this high level diagram - designed for pilots most likely - was to be a quick high-level guide. It was made to be easy to interpret and that was all the pilot needed to understand when looking at those plots. I did not mean that is all the pilot needed to know about flying a plane, fighting in it and firing weapons.

 

 

Yes, I said you made it for super simple comparison that I very clearly pointed it out to you. Then you start twisting my words and attack at me because you can't withstand the fact that you made it super simple "Pilots, always know that you need to be at 21.5 nmi or closer and you are good to shoot!".

 

I am not attacking you. I was telling you that you made a conclusion that was never there. That is not attacking, it is a disagreement.

 

Yes you do.

 

Dude, I just want all of us to be friends and discuss this in a civil manner. I apologize for my "lol" but you have to admit that if someone makes a random conclusion as you did, it might feel a little awkward - almost funny? Let's both be civil from now on, yeah?

 

 

Good, now you are getting it. WE CAN NOT COMPARE THEM!

...

 

As I have explained, it is mixing multiple variables to one graphic that doesn't make sense as is, but lack of context of the all pages that is explaining all the parameters etc is missing.

 

Agreed, and i always agreed - i just wish we had more R-27 data.

 

If you look my graph, I specifically already included all that....

https://forums.eagle.ru/showpost.php?p=4230207&postcount=329

 

So please be more carefully what you are claiming.

 

Sorry, I didn't see that image - it was very small. But honestly, we are both yelling at each other saying the same thing!

[Seaeagle]

That procedure is for jettisoning the missile because those rails aren't carted to drop the payload otherwise. IIRC the seeker may not even be cooled at that point and any combat use of it is the equivalent of using FLOOD mode and other back-up things ... effectively you've got nothing else left and you're hoping that maybe this will work. DCS doesn't model the factors that make this a poor shot.

 

Yeah something like that - to be honest I cannot remember the details, as it was just something I came across once(maybe in the Su-27SK manual).

[Seaeagle]

 

When the R-27T/ET does not have INS, then the INS (gyroscope, accelerometer) must be in the seeker head of the R-27R/ER, as the middle section of the missile is more or less the same (except for datalink antennas, but their signal goes directly through the external wire housing at the bottom of the missile to the seeker section).

 

Yes

 

So where is the INS unit? It cannot be in the rear of the seeker section, because it is filled with circuit boards. And the front is filled with RF components.

 

 

Well I am not an electro-engineer, so I cannot point out which component does what :)

 

To me it makes much more sense that the sensors are in the part with the proximity fuze, which is the autopilot section.

 

It doesn't to me - apart from being labelled "inertial-semiactive radar homing head"(which I think is a clue), the specifications for the 9B1101K clearly state inertial navigation with radio correction as one of two available operation modes(the other being semi-active radar homing):

 

 

ПАРГСН 9Б-1101К работает в диапазоне 10-20ГГц.

 

Применена антенная система с трехосной стабилизацией и цифровые вычислительные устройства, обеспечивающие реализацию адаптивной логики при воздействии естественных и организованных помех.

 

Готовность ГСН 9Б-1101К к применению обеспечивается через 1с после получения целеуказания от системы управления вооружением носителя типа МиГ-29.

 

Дальность захвата целей с ЭПР 3 м2, км........................25

 

Время инерциального наведения с радиокоррекцией

при максимальном удалении от носителя до 25 км, с......30

 

Диаметр корпуса, мм....................................................219

 

Длина (от носка обтекателя), мм.................................1173

 

Вес, кг..........................................................................33,5

 

Вес аппаратной части, кг...............................................21,5

[GGTharos]

Even the R-24T gives a head on lock range of 30km for a F-15 flying at high altitude and high speed without afterburner. With afterburner the range is twice about as much.

 

Where did you come across this figure?

 

R-27T/ET very likely has a better seeker, with even higher ranges.

 

Not really. While the seeker will be better in certain other respects, the material used for receiving the particular wavelengths that enable all-aspect attack has its limitations.

There are power diagrams for other seekers (notably AIM-9s) and engagement limitations graphs for others that show front aspect capability to be quite limited even for missiles more modern than the R-24T.

 

But like you said, circumstances vary widely, so if you have a source for that figure I'd be interested on running some computations based on it.

[BlackPixxel]

Where did you come across this figure?

 

https://www.digitalcombatsimulator.com/en/files/145783/

 

The ranges differ alot and are less under most conditions, but in a high altitude BVR engagement the IR seeker can definetly have a very far lock on range.

[Vatikus]

So where is the INS unit? It cannot be in the rear of the seeker section, because it is filled with circuit boards. And the front is filled with RF components.

It is quite an interesting system actually, INS uses homing head gimbal itself and not separate unit to get gyro readings for the autopilot...

[AeriaGloria]

Simplicity I like it!

[BlackPixxel]

It is quite an interesting system actually, INS uses homing head gimbal itself and not separate unit to get gyro readings for the autopilot...

 

What do you mean? The homing head gives angular rates and acceleration values of the missile during inertial/radio corrected phase (during which the homing head is not locked onto the target)?

Edited March 3, 2020 by BlackPixxel

[GGTharos]

https://www.digitalcombatsimulator.com/en/files/145783/

 

The ranges differ alot and are less under most conditions, but in a high altitude BVR engagement the IR seeker can definetly have a very far lock on range.

 

Thank You.

[GGTharos]

What do you mean? The homing head gives angular rates and acceleration values of the missile during inertial/radio corrected phase (during which the homing head is not locked onto the target)?

 

I think an important thing to consider is that INS is 'guidance to a point', not attitude control - though INS can most certainly help with that and add other data as well.

 

But overall in terms of guidance, the R-27T has no INS guidance. There's no 'fly to this point and activate the seeker' type stuff going on, as opposed to the RF version where the missile itself activates its seeker at some point which is potentially updated via m-link.

Edited March 3, 2020 by GGTharos

[Fri13]

This is impossible, because the complete seeker section is already standing on the left position in the background.

It would mean that the complete RF section of the R-27R seeker behind the antenna is used for "aerodynamic control".

It would also mean that the most rear part of the R-27R seeker is the homing head of the 5V27D missile.

 

Where the text says "Inertially semiactive radio location head" there is a complete seeker head (the complete head that can be seen open in the picture, but with the case+radome).

Where the text says "Block of aerodynamic control" there is the middle section of the missile with the canard controlls.

Where the text shows the next semiactive homing head you see a seeker of a different missile.

 

The open seeker head is just placed in front of the arrangement, with the mounts being exactly in the middle. The text is not describing what is laying in front.

 

Isn't that table same thing as this graphic?

 

 

So on the left of the table there is the seeker part.

Then at the center of the table there is the Autopilot unit (canards).

And at the right of the table there is the propellant section (wings).

[GGTharos]

Why do they list head on ranges for T/ET far beyond what IR seeker could achieve at the moment of launch? It would be an obvious false statement, wouldn't it?

 

 

Because SR-71s and B-1As can get really hot at speed. As for the R-24T, yep, 30km head-on lock on a M2.35 F-15C with AB off which means what exactly - it just turned the AB off, and it's already reaaaaally hot.

But only 2km vs. same altitude, M0.8 F-15C .... the F-35 hasn't got anything to worry about.

Edited March 3, 2020 by GGTharos

[Airhunter]

Because SR-71s and B-1As can get really hot at speed. As for the R-24T, yep, 30km head-on lock on a M2.35 F-15C with AB off which means what exactly - it just turned the AB off, and it's already reaaaaally hot.

But only 2km vs. same altitude, M0.8 F-15C .... the F-35 hasn't got anything to worry about.

 

No serial F-15 is ever going M2.35 or even M2 with any armament or fuel tanks on the jet.

[Fri13]

Just resharing this:

 

https://www.secretprojects.co.uk/threads/r-23-r-24-r-27-aam.60/page-2#post-3647

 

Some data looks pretty pretty interesting.

Max G of missile is: 74 :eek:

Max G of launch aircraft: 07

Max G of target aircraft: 08

Engine thrust: 5000kgf

Warhead fuze setting time: from 1.61 to 3.5 seconds

Maximum range at altitude 20m: 16.5km frontal hemisphere, 4km rear hemisphery

Maximum range at altitude 20km: 90km frontal hemisphere, 20km rear hemisphere.

Time of controlled Flight: 60 seconds

Maximum and minimum altitude of use: from 20 meters to 27.000 meters

Engine weight: 95kg

Warjead weight: 39Kg

 

 

16.5 km at sea level.

60 km at 10 km.

90 km at 20 km.

[SgtPappy]

Just resharing this:

 

https://www.secretprojects.co.uk/threads/r-23-r-24-r-27-aam.60/page-2#post-3647

 

Some data looks pretty pretty interesting.

Max G of missile is: 74 :eek:

Max G of launch aircraft: 07

Max G of target aircraft: 08

Engine thrust: 5000kgf

Warhead fuze setting time: from 1.61 to 3.5 seconds

Maximum range at altitude 20m: 16.5km frontal hemisphere, 4km rear hemisphery

Maximum range at altitude 20km: 90km frontal hemisphere, 20km rear hemisphere.

Time of controlled Flight: 60 seconds

Maximum and minimum altitude of use: from 20 meters to 27.000 meters

Engine weight: 95kg

Warjead weight: 39Kg

 

[ATTACH]229194[/ATTACH]

 

16.5 km at sea level.

60 km at 10 km.

90 km at 20 km.

 

This seems pretty in line with the R-27 plot we have - around 16.5 km at sea level. If only the published information said "speed at impact" instead of "Pk at impact = 0.7" so we could get a better idea of the energy in context with this launch range.

 

Is that defined anywhere?

[Vatikus]

What do you mean? The homing head gives angular rates and acceleration values of the missile during inertial/radio corrected phase (during which the homing head is not locked onto the target)?

Correct. During INS/RC phase homing head is a basis of spatial reference and is not used for SAHR..

[Ironhand]

Isn't that table same thing as this graphic?

 

 

So on the left of the table there is the seeker part.

Then at the center of the table there is the Autopilot unit (canards).

And at the right of the table there is the propellant section (wings).

No. I had initially thought something similar. But stop and think about how short and squat the missile would be if, that were the case. Here is a different image of the same homing head:

 

[Fri13]

C5Fp7NbaL6E

 

So what is the latest information about the updated R-27 family? To see in 2020 or no timetable?

 

About the video, one comment says about this in the factory state [translation]:

 

the plant is no longer there, now unknown people are demolishing it in an accelerated manner, without project boards and without removing construction waste, in violation of all demolition rules, at the moment there is only an administrative building, all the shops and service buildings have been completely demolished.

Edited March 4, 2020 by Fri13