Air-to-Air Missile Discussion

[maturin]

Weapons that are 10 years newer are generally better. What's the problem?

 

And a T-34 can kill an Abrams if the Abrams presents it's rear armor at point blank range. I guess the T-34 is better, then.

[GGTharos]

SARH seeker range of 30nm? That would explain just the basic short inertial phase, certainly. Do you have any links for the seeker range numbers?

 

Nothing handy, sorry. 22nm for 2m^2 for the AIM-7F, 30nm for a larger target (I forget the RCS value, probably 5m^2, ie fighter size).

 

 

I thought it would be necessary for engaging low-flying targets at least to filter out the ground reflections?

 

I implied that :)

 

 

Regarding my earlier target ranging while in EOS mode, I found this description on the supposed modes on the MiG-23:

 

The SIST switch has 5 operating modes. „R, T-R, T, T-phi0, NAV.

The „R“ mode determines the onboard radar as a main targeting system. Also during ground attack the radar can measure distance to the target.

The „T-R“ mode means cooperation between the radar and the IRST, if the radar is jammed the IRST can pick up the target distance and vice-versa.

The „T“ mode prioritizes the IRST as a main targeting system. Also this mode is used in case of radar damage or hidden approach. The S-23E radar works in so called quasi-scan mode. The radar antenna is slaved to IRST sensor and is providing the data for the launch of R-23T.

In the „T-phi0“ mode the R-23T missile seeker is caged to the axis of the plane.

 

Perhaps the same principle is used in the 27/29, although I don't get how hidden approach and radar ranging complement each other.

 

 

If radar ranging is used, the radar contact could be short enough to be rejected as spurious signal or just go unnoticed by the pilot in the electronic clutter. It's stealthier than having your radar on all the time, and the range is longer than the laser.

[Dudikoff]

If radar ranging is used, the radar contact could be short enough to be rejected as spurious signal or just go unnoticed by the pilot in the electronic clutter. It's stealthier than having your radar on all the time, and the range is longer than the laser.

 

It still is a search mode so perhaps it would make sense if the frequency was very low or (as you've said) if the whole transmission was very short so that the RWR ignores it (unless the details of this radar mode are known and the RWR is programmed to detect this mode :) )? But in DCS the target seems to be continuously updated by the search radar so not sure if developers could share some more details on how this mode works and why it's not detected by the target?

 

I updated the original post as there seem to be additional modes (the phi ones) which disable the radar ranging altogether.

Edited October 29, 2013 by Dudikoff

[GGTharos]

It isn't a search mode. The radar is directed by the EOS and pings when/as required. All it does is get immediate information from that train of pulses: Range, bearing, doppler shift.

 

I'm sure the RWR could show it, but RWRs are not perfect: They can sometimes show false contacts. So I believe the pilot might ignore it even if the RWR decides that it's 'something'.

 

As for what's going on in DCS, all I'll say it's that it's a moot point to discuss. The underlying physics and the user interface, as well as vehicle devices need to be developed to get more realistic action.

Edited October 29, 2013 by GGTharos

[Essah]

 

I still have LOMAC, FC1 and FC2 installed.

And I fly FC2 often when nobody is on DCS.

And I'm telling you, fanboys or not, the fact is that all the missiles' kinetic performance has been drastically improved since those simulators.

 

Aim-120C never reaches over 3500km/hr at any altitude in FC1/2.

ER never reaches over 3800km/hr at any altitude in FC1/2.

At medium the AMRAAM is maxed at about 2800km/hr and ER at 3200km/hr.

 

In DCS both reach 5000km/hr (Mach 4.5) terminal V easily..

Plus, the 120C's loft trajectory has been improved and it retains its speed longer.

 

could you do me a favor and provide tacview files of this? It's not that I don't believe you but I would like to see it for myself. Just create a scenario that has Aim-120 and R-27ER and record them in tacview.

 

Since DCS now moddels advanced FM for missiles the drag is much higher which is what's causing the problem in the first place and spawned this whole thread. what's the difference in maximum range for the 2 missiles from FC2 to FC3 ?

 

I have never seen this loft trajectory you talk about but would like to. What parameters do you need for it to do this?

[Ragnarok]

I still have LOMAC, FC1 and FC2 installed.

And I fly FC2 often when nobody is on DCS.

And I'm telling you, fanboys or not, the fact is that all the missiles' kinetic performance has been drastically improved since those simulators.

 

Aim-120C never reaches over 3500km/hr at any altitude in FC1/2.

ER never reaches over 3800km/hr at any altitude in FC1/2.

At medium the AMRAAM is maxed at about 2800km/hr and ER at 3200km/hr.

 

In DCS both reach 5000km/hr (Mach 4.5) terminal V easily..

Plus, the 120C's loft trajectory has been improved and it retains its speed longer.

 

You are not precise enough but there is truth in what you say. For your dilemma try this

Angle of atak does not exist but no maneuvering so called linear range it is more similar to FC3 than FC2.

Edited November 2, 2013 by Ragnarok

[L0op8ack]

You are not precise enough but there is truth in what you say. For your dilemma try this

Angle of atak does not exist but no maneuvering so called linear range it is more similar to FC3 than FC2.

precise，yes

There is a picture in this forum, somewhere.

 

In the lastest DCS World, AA missiles have AoA limit.

For example, max AoA of AIM-120C ~16.616 degree.

That's why AA is so important in 'close shot' scene - missile cannot turn quick enough , which means miss.

 

ARH missiles benefit from loft trajectory. Angle between trajectory and velocity is limited too, ~9.74 degree.

How to peform a 30 degree loft? nose up +20 degree, hold and fire.

Edited November 3, 2013 by L0op8ack

[Ragnarok]

precise，yes

There is a picture in this forum, somewhere.

[ATTACH]90383[/ATTACH]

 

In the lastest DCS World, AA missiles have AoA limit.

For example, max AoA of AIM-120C ~16.616 degree.

That's why AA is so important in 'close short' scene - missile cannot turn quick enough , which means miss.

 

ARH missiles benefit from loft trajectory. Angle between trajectory and velocity is limited too, ~9.74 degree.

How to peform a 30 degree loft? nose up +20 degree, hold and fire.

 

Exactly! Somewhere in the earlier pages I wrote that medium range missile can't follow a target of more than 30deg per/sec. Sudden reversal in the side of missile when the missile is very close to us, in theory, it is sufficient to avoid. The DCS is something similar!

Simple aerodynamic equations are based on calculations with AoA of missiles at the minimum speed up to aerodynamic collapse of the horizontal flight. Generally speaking, the ER after the engine is experiencing a rapid collapse (in low altitude) as opposed to the AIM-120, especially the R77, but however, these missiles have subsequently collapse, are actually gliding with small speed and as such they need a long time to move greater distances in. Speed of ARH is more important for the work of his radar. R77 additionally has a high resistance, and while experiencing the collapse of velocity of all medium missiles still has the smallest range at low altitudes! Situation where ER is the best when it launches from a great height and follows the target down (compared to ARH). AIM-120 is better when launched horizontally at lower altitudes or when to follow up on the target (for ER this is hard work). This is the biggest problem for the ER, where they are best used in kinematics it is easiest to break the radar lock. This is the main reason why ARH is better than SARH. Everything else are little things in the date of manufacture. Defensive ability of ARH's primary concept of constructors, of course!

Edited November 3, 2013 by Ragnarok

[GGTharos]

Exactly! Somewhere in the earlier pages I wrote that medium range missile can't follow a target of more than 30deg per/sec.

 

 

And you would be incorrect. A plane rating at 30deg/s means nothing to a missile. You can be at 200kt and rating 30deg/s. Does the missile care? No - why? You're not translating across its plane of view at 30deg/s.

 

Sudden reversal in the side of missile when the missile is very close to us, in theory, it is sufficient to avoid.

 

It's an in-plane turn, the missile will hit unless it's so slow that it can't turn any longer.

 

The DCS is something similar!

 

And it's wrong.

 

The only thing that matters is available g. It doesn't matter how fast your plane or the missile can turn. Available g is what dictates whether you can out-maneuver that missile or not. The missile needs 3x target g (when out of plane) to hit its target. In-plane it doesn't need quite as much, and the proximity fuze will deal with a lot of issues that could cause a near-miss.

[Ragnarok]

And you would be incorrect. A plane rating at 30deg/s means nothing to a missile. You can be at 200kt and rating 30deg/s. Does the missile care? No - why? You're not translating across its plane of view at 30deg/s.

 

To better clarify! If we go over the plane for 15deg of the direction of the oncoming missile, at a distance of 1.5km, missile has to go in front of the aircraft to intercept the example of 20deg, not like an aircraft at 15deg. If a sudden turn in the opposite direction, we are giving the task to the missile interception reorient to the opposite side. Although I say 30deg / s, I think 3/4 sec is how you might maneuver (this is just an example). For 3/4 sec for me to go around 22deg. Means to 15deg on one side I turn to the other side 7deg in relation to the missile. In order that missile to intercept, have a task of 20deg one side move to 10 deg on the other side. Because 3/4 sec missile can sometimes exceed approach 800 meters (point of interception is reduced this time), angle displacement can be for an additional 10deg on the other side starting from the initial position of the 1.5km which makes the overall task of 40 deg, ! The maximum turn missile depends, of course, limits G force. But the optimal speed for the most G force is not helpful if the electronics response is not consistent with the reaction of controllable surface missile. Because of this maneuver the plane does not even have to turn up quickly (although desirable) to overcome this effect. because of this situation, moving on the opposite side of the intercept, the missile must endure 3-3.5 higher G-forces from the plane, and because the velocity of the missiles (medium range) in a similar relation higher, than the plane! If the maneuver start earlier, missile have an easier task then no problem to escort the target.

Edited November 3, 2013 by Ragnarok

[GGTharos]

You're trying to make things too complicated. The real effect is this:

 

A missile doesn't care about you reversing. It only cares about out-of-plane maneuvers, in terms of its abilities, because there it will experience additional problems like seeker settling etc.

 

The control loop delays and available g just need to be enough to match the target maneuver.

 

The only time where we need to talk about deg/s is when the missile is launched in such poor parameters that the target is crossing the missile's path so fast that it exceeds the missile seeker slew limit OR the missile does not have enough available energy to to complete the turn while keeping the target in view. This will only happen at short ranged, poor parameter launch conditions.

 

It is not a problem for a missile that has been launched in good parameters; it doesn't matter what you do then because it is not physically possible for you to change the geometry in such a way that would cause any of the above problems. The only thing you can do to take advantage of seeker settling and other problems is to do an out-of-plane maneuver like an orthogonal roll. It has to be well timed, and the more modern the missile you face, the more lucky you need to get for it to work.

 

The only other caveat to all this is pulling more g than the missile's full available g - eg. sparrow and R-27 have 24-25G command (ie. 8g target, more modern missiles have 10-12g target), if you pull out-of-plane with 9g, you will probably generate a good miss distance.

But if you try to increase the g in an in-plane maneuver, you'll probably eat the missile.

 

Talking about deg/s really makes no sense in this case. The only thing that matters is g available, which is based on the missile's speed and pressure altitude.

Edited November 3, 2013 by GGTharos

[Ragnarok]

Then tell me this: on what type of interception is carried out in the last couple of kilometers from the target? (ARH or SARH)

 

- full interception?

https://www.dropbox.com/s/ajew3s25taqqiz0/2013-11-03_222706.png

 

- semi interception?

https://www.dropbox.com/s/5pm71tvyr4m72us/2013-11-03_222718.png

 

- method of "three points"(T/T)?

https://www.dropbox.com/s/2joantl8y97mtir/2013-11-03_222649.png

Edited November 3, 2013 by Ragnarok

[GGTharos]

Proportional navigation, and the more modern the missile is, the more filters are applied to PN (actually, terminal is usually not just PN, but APN + other fun things).

You're trying to compare AAMs to old SAM types. AAMs use PN.

[Grinch]

So what is the current state of affairs for MRMs? We're up to 107 pages now. For those of us newer to FC3 and FC in general, should we be using 120Bs or Cs with the current patch?

 

I've been playing online and launching 120Cs at approximately 15 nm and have a very, very low pk. I'm tempted to give the B mod a go to see if I have any better success. I'm launching at higher altitudes than the target with the intercept dot centered in my hud.

 

It appears that the 27ERs have no problem being launched from a greater distance against a foe at a greater altitude. I know you all are going to want track files, but just speak to me in general terms. What's the deal these days?

[Frostie]

So what is the current state of affairs for MRMs? We're up to 107 pages now. For those of us newer to FC3 and FC in general, should we be using 120Bs or Cs with the current patch?

 

I've been playing online and launching 120Cs at approximately 15 nm and have a very, very low pk. I'm tempted to give the B mod a go to see if I have any better success. I'm launching at higher altitudes than the target with the intercept dot centered in my hud.

 

It appears that the 27ERs have no problem being launched from a greater distance against a foe at a greater altitude. I know you all are going to want track files, but just speak to me in general terms. What's the deal these days?

It all depends on what the bandit is doing when you launch on him, if he is medium to high 15nm is a good pk using TWS, provided he doesn't anticipate your shot, but against a low bandit he can quickly put your missile on the beam and he will find it easier to defeat. The 120B is similar to the R-77 and both are inferior to the 120C.

 

Against a low flying bandit you should be able to defeat him, fail in this situation by him defeating your shot and you pushing too much.

Against a medium flying bandit you should have no trouble defeating him providing you do the right thing and don't push in too much if he is working well.

 

The main issue is understanding what the bandit is doing and how your attack is progressing and then combining this with knowing when to push and when not to, this is what determines whether you win or lose rather than how the missiles are performing or not performing. Also understand that just because you fired a missile in good parameters doesn't mean a kill will follow this is true of all missiles and happens to them all a lot.

[Grinch]

Yeah, I understand notching and the tactics involved. My question is in regards to the sim itself--not that of tactics or real world scenarios.

[L0op8ack]

And you would be incorrect. A plane rating at 30deg/s means nothing to a missile. You can be at 200kt and rating 30deg/s. Does the missile care? No - why? You're not translating across its plane of view at 30deg/s.

 

I think what Ragnarok said is LOS rate limit.

He is right, so far.

LOS rate limits of AIM-120B/C/ R-77, are the same, 29.79 degree/sec, as FC2 did.

 

So what is the current state of affairs for MRMs? We're up to 107 pages now. For those of us newer to FC3 and FC in general, should we be using 120Bs or Cs with the current patch?

 

I've been playing online and launching 120Cs at approximately 15 nm and have a very, very low pk. I'm tempted to give the B mod a go to see if I have any better success. I'm launching at higher altitudes than the target with the intercept dot centered in my hud.

 

It appears that the 27ERs have no problem being launched from a greater distance against a foe at a greater altitude. I know you all are going to want track files, but just speak to me in general terms. What's the deal these days?

 

120C is the best for 1 vs 1, R-27ET is the best for MP. :)

120C head-on shot, dot centered, for reasonable pks:

high to medium, 6-8nm

high to high, 10-12nm

medium to low, 5nm

 

R-27ET will get LA within 30km if target turns AB on.

 

SARH missiles benefit from altitude advantages, but suffer from lock-break and chaff.

Edited November 4, 2013 by L0op8ack

[Frostie]

Yeah, I understand notching and the tactics involved. My question is in regards to the sim itself--not that of tactics or real world scenarios.

Sorry but it seems to me you don't understand by believing that your missiles are useless while ER's are performing better in the sim.

The ER is slightly faster than the 120.

But launched at the same altitude ER's reach a target at approx. the same time as a 120C but a 120C will go active well before this.

The AIM-120C has better chaff rejection than the R-27.

The AIM-120C has a better maxG than the ER.

The AIM-120C has a bigger kill radius at detonation.

Against a much lower target a 120C will have much more range and speed than an ER, the only advantage the ER will have is the lack of ground clutter.

[Teknetinium]

Sorry but it seems to me you don't understand by believing that your missiles are useless while ER's are performing better in the sim.

The ER is slightly faster than the 120.

But launched at the same altitude ER's reach a target at approx. the same time as a 120C but a 120C will go active well before this.

The AIM-120C has better chaff rejection than the R-27.

The AIM-120C has a better maxG than the ER.

The AIM-120C has a bigger kill radius at detonation.

Against a much lower target a 120C will have much more range and speed than an ER, the only advantage the ER will have is the lack of ground clutter.

 

I hope some of this will change, ER-27 should be faster the Aim-120C!!!

[Frostie]

Sorry but it seems to me you don't understand by believing that your missiles are useless while ER's are performing better in the sim.

The ER is slightly faster than the 120.

But launched at the same altitude ER's reach a target at approx. the same time as a 120C but a 120C will go active well before this.

The AIM-120C has better chaff rejection than the R-27.

The AIM-120C has a better maxG than the ER.

The AIM-120C has a bigger kill radius at detonation.

Against a much lower target a 120C will have much more range and speed than an ER, the only advantage the ER will have is the lack of ground clutter.

 

I hope some of this will change, ER-27 should be faster the Aim-120C!!!

Why would it change much, it's pretty much how it should be. The FC3 AIM-120C is a C5.

 

The ER is slightly faster than the 120.

This is still WIP.

 

The AIM-120C has better chaff rejection than the R-27.

The 120C is more advanced missile so this seems correct, plus the 120C5 had ECCM upgrades over the previous versions, though this was improved again with the C7.

 

The AIM-120C has a better maxG than the ER.

The above probably applies.

 

The AIM-120C has a bigger kill radius at detonation.

I'm not sure about this, maybe GG can shed some light here as the TDD and QTDD weren't incorporated until the C6 and C7 onwards while the ER packs more explosive.

Edited November 4, 2013 by Frostie

[Ragnarok]

Against a much lower target a 120C will have much more range and speed than an ER

 

At low altitudes when a smaller distance, the most important factor for range is the time of the engine. The second is the resistance (diameter of missile and AoA) that also limits the maximum speed ( even if the benefit is for Mach 0.5 at high altitude, low altitude of this difference is almost obliterated). Massive missile in these conditions will not add to the range of its inertia as a high-altitude! At high altitudes and long range all the reversed: 1. max speed + inertia (mass) most important; 2. resistance; 3. time of the engine smallest factor, believe it or not!

 

Should be noted that mass is a one factor for AOA (a factor of resistance), but I said it as a factor of inertia.

 

if the engine for AIM-120C is 13 seconds and the engine for ER 9 seconds, if this is relevant, then the range at low altitudes is realistic in DCS.

 

My advice for playing with ER (no for 51., they known this :) ) is: shoot ER high over the enemy and keep the lock on below the enemy, deep diving.

Edited November 4, 2013 by Ragnarok

[GGTharos]

Not necessarily. The arrangement of the rocket stages for the R-27ER does not necessarily support this.

 

I hope some of this will change, ER-27 should be faster the Aim-120C!!!

[GGTharos]

In certain documents created prior to AIM-120C6 delivery the lethal range of the 120C (and in some cases B, but it's been a while since I looked) is described as 50', which is about 15m. (Almost no one ever talks about triggering range of the TDD, so we can only assume).

 

This is attributed to basically more powerful/faster explosives that propel the frag at higher speed, as well as the ability to direct them. However lethal radius with the 120 is very tricky: The new warhead which is lighter allegedly has the same performance, but more importantly it is hinted that the 120's miss distance is far smaller than this lethal radius (typical assumptions that I have seen against a maneuvering target put it anywhere from 5m to 10m).

 

The other problem is that the fuzes in game detonate against a specific point on the plane, instead of against the 3D shape. At the same time, lack of frag modeling and the fact that the in-game TTD is always a sphere can cause some strange situations where missile explode but do no damage, where they should have achieved a direct impact.

 

The AIM-120C has a bigger kill radius at detonation.

I'm not sure about this, maybe GG can shed some light here as the TDD and QTDD weren't incorporated until the C6 and C7 onwards while the ER packs more explosive.

Edited November 4, 2013 by GGTharos

[blkspade]

The other problem is that the fuzes in game detonate against a specific point on the plane, instead of against the 3D shape. At the same time, lack of frag modeling and the fact that the in-game TTD is always a sphere can cause some strange situations where missile explode but do no damage, where they should have achieved a direct impact.

 

I'm guessing the lack of fragmentation modeling is the core reason for fuze detonation point. I've seen missiles get scary close to a target that detonation would likely damage or disable the aircraft, but they just don't blow. Just a couple days ago I was in an engagement where I had pretty much kinematically defeated what I assume was an ET. I looked over my shoulder in time to see it slowly creeping up me from my 8 o'clock. It was close enough that I probably could have read the markings on it, if my initial response wasn't 'oh sh*' hit the burner and climb. It was definitely guiding to me while my TEWS was clean, but did not have the energy to climb with me. As close as it was a proximity detonation would have certainly done damage.

[GGTharos]

I'm guessing the lack of fragmentation modeling is the core reason for fuze detonation point.

 

Nope, it's just how it's programmed. The two things have nothing to do with each other.