R-27EA (AE) on Su-27

[Pilotasso]

“Soviet/Russian Aircraft Weapons Since World War Two” by Yefim Gordon, page 48, quote:

 

“This (R27-AE) makes it the first Russian missile to utilize the fire and forgot principle …” end of quote.

 

Further in the same paragraph, quote:

 

“Outwardly the R-27AE can be discerned from the R-27ER by the conical shape of the radome instead of the usual ogival one, a feature which has reduced overall length by 45 mm (1 49/64 in).”

OMG

Yeah it was long overdue one of your usual polemics! :lol:

 

Looks like you miss some more (and I quote) "verbal abuses", and you had to come back with this again.

[Kula66]

I've got a picture somewhere of the seeker (AGAT 9B-1103M active radar) for the PROPOSED R-27AE ...

 

If there is a specific passive homing version of the R-27 - the P ... then should the vanila version be capable of HOJ?

[Pilotasso]

The P is like any other radar missile (SARH or otherwise) with radar guidance removed and have only 1 mode that is passive listening of radiation from enemy emmisions. I expect it to have very weak PK. Hitting static targets that have sut down their radars is hard enough, imagine one that moves at mach 0.9 or above. Worse, the lates fashion are LPI radars, theres litle you can do with equipment that can fit in the small space provided by the missiles body.

[Alfa]

I've got a picture somewhere of the seeker (AGAT 9B-1103M active radar) for the PROPOSED R-27AE ...

 

If there is a specific passive homing version of the R-27 - the P ... then should the vanila version be capable of HOJ?

 

HOJ(Home On Jam) and "anti-radar" capability are two different things. The former is an alternative way of homing on a target jamming your radar - i.e. homing on a highly directional and continious emmission, while the latter means the ability to engage a target via its "normal" radar emmission, such as an AWACS type of surveillance radar.

[p_o_d_2_2]

Sorry for going a little OT, but can HARMs be used as anti AWACS or are they purely AG weapons?

[Force_Feedback]

We should have the R-27(E)P missiles though, for AWACS blasting.

[Pilotasso]

In theory yes if you know wich frequencies to tune it, but it would have a range that is too short to provide the attacker any room before he is attacked by the defenders.

[golfsierra2]

Have searched for some days now on the internet and could not find any source stating that the R-27AE ever made it into service.

BTW I came across this nice site

 

http://www.canit.se/~griffon/aviation/text/missiles/aam.html

 

which adds more figures to the recent disussions of max missile ranges and so on...

[golfsierra2]

a). every IR homing missile "utilizes the fire & forget principle".

 

b). the R-27AE never made it into production, so the first Russian radar guided air to air missile to be "fire & forget" would be the R-77.

 

I'm not happy with the statement that an AR-missile is a real fire and forget weapon. Neither the R-77 nor the AIM-120 can be fired and the aircraft then immediately braking away and braking lock subsequently. At longer distances, you still have to support the missiles for a good portion of their flight path before their organic radar is able to pick up the target by itself (going pitbull).

 

R-77 and AIM-120 only would be fired as fire & forget at very short distances, that is it is going off the rail already active. Which likely would be almost the same envelopes like for effective firing an IR-missile.

[Alfa]

Have searched for some days now on the internet and could not find any source stating that the R-27AE ever made it into service.

 

No but why would you look for one? :) .

 

We already found a reliable source (IIRC its somewhere in this thread) stating that early R-27AE development was abandonned because it was determined to be better to concentrate the efforts/funding on the R-77 design.

[Alfa]

I'm not happy with the statement that an AR-missile is a real fire and forget weapon.

 

Perhaps but it was nevertheless with the introduction of ARH missiles that the term "Fire & forget" came about ;) .

 

Neither the R-77 nor the AIM-120 can be fired and the aircraft then immediately braking away and braking lock subsequently.

 

Yes they can - at short distances where the seeker can acquire the target by itself prior to launch, an ARH missile is truely "fire & forget".

 

At longer distances, you still have to support the missiles for a good portion of their flight path before their organic radar is able to pick up the target by itself (going pitbull).

 

No you don't necessarily have to support the missile at longer distances - the INS of the missile wil still fly towards predicted target impact point on its pre-launch data-set and the ARH seeker still have the possibility to pick up the target at that point. But keeping a target "bugged" and thereby providing radio command update to the pre-launch data will obviously increase that possibility.

 

R-77 and AIM-120 only would be fired as fire & forget at very short distances, that is it is going off the rail already active. Which likely would be almost the same envelopes like for effective firing an IR-missile.

 

I tend to disagree. Although maximum acquisition range against a head-on target might be similar(something in the 10-15km range) for an ARH seeker(of AIM-120/R-77 class) and an IR seeker(of AIM-9/R-73), the fact is that you would be more likely to achieve this maximum range with an ARH seeker - given the head-on aspect, which favours radar means over IR ditto. In more adverse aspects and especially tail-chase the IR weapon would have the advantage - partially due to the IR seeker and partially because traditional IR AAMs are smaller and more agile weapons better suited for this type of engagement.

[Alfa]

OMG

Yeah it was long overdue one of your usual polemics! :lol:

 

Looks like you miss some more (and I quote) "verbal abuses", and you had to come back with this again.

 

No need to taunt the guy for quoting a book on the subject at hand Pilotasso.

[Kula66]

HOJ(Home On Jam) and "anti-radar" capability are two different things. The former is an alternative way of homing on a target jamming your radar - i.e. homing on a highly directional and continious emmission, while the latter means the ability to engage a target via its "normal" radar emmission, such as an AWACS type of surveillance radar.

 

So one method homes in on a source of RF energy and the other method homes in on a source of RF energy. Ok ... so why build a completely new seeker for that?

[Alfa]

So one method homes in on a source of RF energy and the other method homes in on a source of RF energy. Ok ... so why build a completely new seeker for that?

 

Can you take a HOJ shot against a non-jamming target aircraft - even if it has a solid STT lock on you?.

 

No.

 

Can you engage a non-jamming target radar - especially one that has a solid STT lock on you - with an anti-radar missile?

 

Yes.

 

One is a sophisticated active radar seeker with a simplistic passive mode as back-up, while the other is a sophisticated passive radar seeker capable of homing on a variety of radar sources in varies modes of operation.

[Kula66]

One is a sophisticated active radar seeker

 

Did you mean semi-active? ;)

[Alfa]

Did you mean semi-active? ;)

 

No I was just continiuing along the lines of the posts above concerning ARH seekers, but it also concerns a SARH seeker - i.e. actively processing reflected radar energy, but with a back-up feature that allows it to home passively and directly on target's jammer emmission.

[golfsierra2]

No you don't necessarily have to support the missile at longer distances - the INS of the missile wil still fly towards predicted target impact point on its pre-launch data-set and the ARH seeker still have the possibility to pick up the target at that point. But keeping a target "bugged" and thereby providing radio command update to the pre-launch data will obviously increase that possibility.

 

That is against any practical real live firing technique. Firing at almost max range, and instantly breaking away (breaking lock by that) certainly will end up in a 'trashed' misssile.

 

In German F-4F, the WSO is calculating the time period, that the AIM-120 has to be supported after launch, after this time elapsed (and the missile is considered pitbull), they break lock and turn away.

 

In an F-15, there is the indication in the HUD which 'counts down', telling the pilot how long he has to support the missle with a radar lock befor he can break away.

 

Firing an AAMRAM as you put it only is a shot of opportunity with a very low PK. Nobody would waste precious AMRAAMS like you described it.

[golfsierra2]

No but why would you look for one? :) .

 

Because earlier in this thread, there was mentioned a book source telling this and I doubt it.

 

I still can live very well with my R-77, R-27ET and R-73 mix

[GGTharos]

The AMRAAM's acquisition range against a 'medium' target (a fighter) is about 13nm, at least as demarcated on F-16 HUD's for the AIM-120A (specifically against another F-16). That's about 6nm outside the Rtr.

It would thus seem that 'fire and forget' is a very real thing.

[GGTharos]

Because each source of RF energy is different :)

 

A jammer will create 'noise' which is in some respect similar to that of the radar which is supposed to be illuminating the target. Because the signal lacks some things that the actual reflected signal would have, the HoJ shot might have less Pk. The jamming signal will also typically be characterized by higher power and more spread out bandwidth.

 

A radar signal that you home in on in an anti-radar fashion is much 'cleaner', in that the bandwidth is narrow, but it may not behave anything like what YOUR reflected radar signal would.

 

In addition, things like AESA/PESA radar or just slowly sweeping radars with reduced sidelobes would probably kill the Pk of an ARM shot against a moving target.

 

This is why you see the 'real' AWACS killers being active radar guided missiles or IR, not passive RF homing. You could barrage a bunch of passives and one would probably hit, but why do it when you can use one or two much higher Pk missiles and accomplish the same task with less money spent?

 

So one method homes in on a source of RF energy and the other method homes in on a source of RF energy. Ok ... so why build a completely new seeker for that?

[Pilotasso]

90% of the people have become specialists in obtaining kills that way. No one cares about supporting their shots anymore. Thats why Im wayting for BS so hard. It will return some truth to it again. Hopefully maddogs at 20 miles (or break lock to run away 20 miles before TTA) will be a thing of the past, and that includes the AMRAAM (It starts to be as serious as the ET was months back and thats ALOT :D )

[Kula66]

Well said Pilotasso! Lets hope BS has fixes this arcady behaviour!

[Alfa]

That is against any practical real live firing technique. Firing at almost max range, and instantly breaking away (breaking lock by that) certainly will end up in a 'trashed' misssile.

 

That would depend on the range in question and not least the nature and actions of the target.

 

In German F-4F, the WSO is calculating the time period, that the AIM-120 has to be supported after launch, after this time elapsed (and the missile is considered pitbull), they break lock and turn away.

 

In an F-15, there is the indication in the HUD which 'counts down', telling the pilot how long he has to support the missle with a radar lock befor he can break away.

 

Firing an AAMRAM as you put it only is a shot of opportunity with a very low PK. Nobody would waste precious AMRAAMS like you described it.

 

Of course you would support the missile in its cruise stage to obtain proper PK......if you can. The point I was making was that even if your are forced to go defensive and break lock in the process, it doesn't necessarily mean that your missile is wasted, as would certainly be the case with a SARH weapon.

 

Secondly, you are making a very distinct division between "close range" and "long range" in your argumentation. It should be obvious that the longer the range the less likely it is that the missile, without midcourse guidance, will manage to end up in a proximity/aspect to target where the seeker can acquire it on its own.

 

However, imagine a situation(let's use the R-77 as an example) where you have a head-on target locked at 25 km range and launch your missile - now the R-77 seeker has a stated max acquisition range of some 16km against a medium sized fighter target, so the target is outside seeker range at this point and you intend on keeping the target locked for a while until you are confident that the missile is homing on its own, but need to take evasive action yourself and loose the lock in the process. How long will the missile be flying without midcourse guidance before target is within seeker range and how much will it matter? - consider:

 

- that the missile has a pre-loaded fly-out point to follow in the direction of target.

 

- the combined closure rate of the missile/head-on target vs. the range(~10km) it will have to cover before reaching seeker acquisition range.

 

- that a missile fired from TWS isn't getting continious split second update anyway.

[Kula66]

Because each source of RF energy is different :)

 

Some forms of jammer are EXACTLY like an out-going radar source ... thats how they work!

 

This is why you see the 'real' AWACS killers being active radar guided missiles or IR, not passive RF homing. You could barrage a bunch of passives and one would probably hit, but why do it when you can use one or two much higher Pk missiles and accomplish the same task with less money spent?

 

But our Soviet friends developed them ... they must have thought they would work and be worth while! The implementation of some of their technology may suck, but they have some very bright people and good ideas!

[GGTharos]

Yep, but look at all the new developments ... ARH ... not ARM.

The idea of using ARMs against aircrafts seems to be getting put away slowly.

 

And yes, some forms of jammer pretend to be YOUR radar for the missile's benefit. This is why youhave ECCM ... because you're working with frequencies/waveforms similar to what the missile normally uses, so you don't need additional hardware to detect and process additional frequencies etc.