About Sidewinders - and other missiles

[+Crusader]

I'm working on updating the AIM-9 (and other types) in the game. Started already back in 2018. First release will be using stock 3d, a 2nd release with (hopefully) as many accurate 3d as possible later on.

This update/mod will change the way the player has to employ the missile. Accurate aiming (pulling the sight/aiming mark/reticle directly on the target) is required to get a seeker lock-on.  Until now,  it is easy to get a lock-on because the missile seekers are set up by default to act as a "super-seeker", covering the full seeker gimbal angles. With that removed, its more fun/challenging to fight with IR missiles and it also makes more sense to actually use the radar for targeting. That works (seeker slaved to radar) only with few AIM-9 types,  the 9L, 9M, 9P-5, 9JULI and the 9X. The AIM-4D also has this function and the French Magic 2.

To be continued..

[+Stratos]

Sounds interesting Crus, looking forward to it.

[+KnightWolf45]

cool!

[tiopilotos]

I always considered air to air missiles of the game (both blue and red side) as hyper effective. Short range IR missiles can be launched from long distances, from very wide angles and sometimes their kinetic energy is quite superior. I think that this project is badly needed. 

[jeanba]

Looks good !

[+Crusader]

The "super seeker"

In the TW weapon Editor, the IR missiles have a option "Seeker Uncage" which can be set On/Off

By default, all AIM-9 starting with the 9E have this option enabled. What does it do?  The seeker will search the whole Field of Regard (FOR) as defined by the Seeker Gimbal Limits (generally +/- 40° for all -9 between the B and the X) with the speed set by the Seeker Tracking Rate value. And that is the "super seeker", covering a large area in front of the aircraft in SF2. Such a seeker function is correct for few real missiles, the French Magic series is one type which does have a seeker covering a large FOR and scans it with a very high rate. The Magic has been designed as a close-combat missile able to be used in a dogfight without the need to use a radar or radar-lock.

So, "Seeker Uncage" has been disabled - is that bad/does it affect the AIM-9 in a bad way?

No. The game has functions which are automatic, out of player control. What I call "auto-uncage is one of them. with the seeker locked-on to a target, the seeker is automatically uncaged and keeps tracking the target until the exceeding the Gimbal Limits / the Tracking rate / background noise / decoys  break the lock.

A second function is a automatic preference for the target positioned closest to the players center of view. Even with a radar lock and a missile with a slaved seeker. That is close to a real "Manual Boresight" function, where the pilot manually  re-cages the seeker (back from the radar slave mode) to point the seeker (by maneuvering) to another target.

The screenshot shows that I have locked the target on my left, but the seeker circle is on the target in front of me. Missile used is a 9L.

 

To be continued..

[+streakeagle]

15 hours ago, tiopilotos said:

I always considered air to air missiles of the game (both blue and red side) as hyper effective. Short range IR missiles can be launched from long distances, from very wide angles and sometimes their kinetic energy is quite superior. I think that this project is badly needed. 

The missiles were not always hyper effective. In fact, they were originally only a little better or in some cases worse than historical effectiveness. I don't know when you started playing SF, but the original SFP1 early AIM-9s and AIM-7s were very likely to be duds or miss. The AIM-7C and AIM-7D were at best 25% effective against easy targets and couldn't hit anything else. I could get the AIM-7E to work fairly well head on, but it otherwise didn't track/hit that often. The AIM-7E2 was good from a stern dogfight position, but didn't do so well with the head on shots. The AIM-9B needed a solid stern position on a non-maneuvering target. The AIM-9E wasn't much different. But if you flew Navy jets, you got the half-decent AIM-9D and once you graduated to the AIM-9G/H, you had an excellent weapon, just short of AIM-9L performance, i.e. lacking the head-on capability.

So what changed? TK was desperate to make the game more appealing to casual gamers and they would be complaining about not being able to hit anything. So, TK made some changes that led to the missiles being a lot easier to employ, at least for the player.

[tiopilotos]

@streakeagle Excuse me but it was just a general conclusion I have made after so many years of flying in SF2. Yes... there are few cases like AIM-9B or Shafrir-2 where in game performance comes close to real life. Concerning AIM-7E wikipedia states a Pk of less than 10% in Vietnam. In SF2 I usually get one kill out of 4-5 shots against easy targets with AIM-7E. Later Sparrow versions such as 7F or 7M seem to have far superior performance. Everytime these missiles are fired and the target can not jam or deploy chaff, then usually it's a kill. I get at least 3 kills out of 4 shots with 7F (Pk=0.75) compared with the 0.55-0.59 which wikipedia states for 7M which is actually better than 7F. I don't know what other users experience with Sparrow but in my experience in SF2 the missile seems to be much superior than the real one.

I agree that TK made some things easier for the blue side player and not only speaking about air to air missiles. Stock SAMs are quite ineffective compared with what they can actually do.

@Crusader So, if I have understood correctly, if a missile has Seeker Gimbal Limits +/- 40 then FOV is 40*2 = 80 ?

Edited April 22, 2020 by tiopilotos

[+Crusader]

Yes, the SeekerGimbleLimit=  value is the angle measured from boresight 0 to the max angle the seeker can move off-boresight. The whole Field Of Regard (FOR) that the seeker can cover is 80° with a GimbleLimit=40

The AIM-7 will receive some attention as well. For example, max flight time of the 7E's is 40 seconds. And the 7E-2 does not have a shorter range than the 7E, it only has a shorter minimum range.

But I digress...

[tiopilotos]

I think that you should also increase the fuze distances in order to simulate the hit but not kill situation. Almost 100% of stock missiles kill an aircraft when impact.

[+Crusader]

Good that you mention fuzing distance - thats my next point to elaborate on :)

Stock missiles have a fuzing distance value of 0 or 0.5 meters. Ive changed that to values (for AIM-9) of 6.0 and 8.0 meters, depending on the type of fuze of the AIM-9 variant. The result is that about 75% of the hits still result in fatal destruction, with 25% causing damage and the target keeps flying on. Some crash after a few minutes or catch fire. Big bombers sometimes need a second AIM-9 hit.

Beagle screenies: first a proximity-fuzing hit which caused damage to the right wing, second Beagle is hit fatally.

[+Crusader]

AI F-4 with AIM-9J -  the target Mirage is still within the seeker FOR and the 9J makes the turn and hits

[+Crusader]

Some additional proxy-pix

[+strahi]

I hope it's not a big digression, I wrote about it a long time ago, did you notice that it was impossible to lock on cruise missiles with IR missiles? 

[+Crusader]

Naw :)

No, Ive not attempted to shoot down a cruise missile with IR missiles. Probably wont work because the game doesnt "categorize" the cruise missile weapon as a target for IR missiles, only for radar missiles.

Another thing is that while IR missiles do turn skywards for the sun (after loosing lock or with too much "sun" in the seeker FOV", there is no change of the IR acquisition tone if the player points the seeker at the sun.

[+strahi]

3 minutes ago, Crusader said:

Naw :)

No, Ive not attempted to shoot down a cruise missile with IR missiles. Probably wont work because the game doesnt "categorize" the cruise missile weapon as a target for IR missiles, only for radar missiles.

Another thing is that while IR missiles do turn skywards for the sun (after loosing lock or with too much "sun" in the seeker FOV", there is no change of the IR acquisition tone if the player points the seeker at the sun.

Of course I didn't even doubt it 

Btw, there have been cases of shooting down cruise missiles with IRM.

[+Crusader]

AFAIK some Tomahawks, and decoys as well.

EDIT: And the Kuwaitis attempted to shoot down Silkworms with SA-7.. no hits!

Edited April 22, 2020 by Crusader

[+Crusader]

AIM-9 project - next point: the "reduced smoke" motor.

One probably reads about that when reading/finding info (old books, lists with AIM-9 variants) in connection to the AIM-9E-2. Its true, but it is only the tip of the iceberg :D And it was not in use in the late 60s. The new motor has a new grain which burns cleaner, producing less smoke. Theres more to it, the motor also has more thrust and gives the missile a higher impulse. Production of the new SR116-HP-1 motor started in 1978, with first deliveries 1979/80. While thrust per second is slightly increased over the old Mk17 motor, the burn time is 3.2 seconds versus 2.2 seconds of the Mk17. The new motor is used with variants of the 9B/E/J/N/P series.

The combination of motor and fuse define the AIM-9 variant in combination with the Letter-specific Guidance and Control Section (GCU), the basic variants have no  dash-suffix (e.g AIM-9J = basic J variant)

Variant = motor + fuze

9J = Mk17 + Mk303

9J-1 = Mk17 + DSU-21

9J-2 = SR116 + Mk303

9J-3 = SR116 + DSU-21

This matrix applies to all B/E/J/N/P variants, the 9P has two more:

9P-4 = SR-116 + DSU-21

9P-5 = SR116 + DSU-21

Fuses: the Mk303 is the original IR influence fuse, the DSU-21 the new optical/laser fuse available from ~1979.

Thus the -2 and -3 are generally the best variants, with the 9P-4/P-5 which have all-aspect capability having a further improvement.Of all the variants mentioned above only the 9P-4 and 9P-5 seeker can be slaved to the radar. For all other variants it is required to point the seeker directly at the target to obtain a lock-on.

To be continued..

EDIT

Edited September 30, 2020 by Crusader

[+Stratos]

I love you're taking care of the fuze distances too, would be amazing once you release it. BTW, will all those changes affect the AI missiles as well, right?

[jeanba]

I had tested fuzing distance for the Magic sometimes ago, and did not find any significant changes in terms of damages to the target plane.

On 22/04/2020 at 7:22 PM, Crusader said:

Good that you mention fuzing distance - thats my next point to elaborate on :)

Stock missiles have a fuzing distance value of 0 or 0.5 meters. Ive changed that to values (for AIM-9) of 6.0 and 8.0 meters, depending on the type of fuze of the AIM-9 variant. The result is that about 75% of the hits still result in fatal destruction, with 25% causing damage and the target keeps flying on. Some crash after a few minutes or catch fire. Big bombers sometimes need a second AIM-9 hit.

Beagle screenies: first a proximity-fuzing hit which caused damage to the right wing, second Beagle is hit fatally.

 

[+Crusader]

Yep, I do remember the test with the Magic.

I have also changed/updated the warhead explosive mass for my mod. Most stock missiles have the complete warhead weight set for the explosive mass. The real amount is much less. Ive gone one step further. Ive converted the several different explosive types to their TNT equivalent. The results are between 4.9 kg and 6.2 kg explosive mass for the AIM-9's.

Combined with the increased fuzing distance, the results are more damaged targets and less immediate fiery explosions.

[+Crusader]

3 hours ago, Stratos said:

I love you're taking care of the fuze distances too, would be amazing once you release it. BTW, will all those changes affect the AI missiles as well, right?

Only TK really knows what the AI is doing with them    Cant really see any thing different with AI jets compared to the player. Their hit rate with early missiles is miserable as well!  

[jeanba]

19 hours ago, Crusader said:

Yep, I do remember the test with the Magic.

I have also changed/updated the warhead explosive mass for my mod. Most stock missiles have the complete warhead weight set for the explosive mass. The real amount is much less. Ive gone one step further. Ive converted the several different explosive types to their TNT equivalent. The results are between 4.9 kg and 6.2 kg explosive mass for the AIM-9's.

Combined with the increased fuzing distance, the results are more damaged targets and less immediate fiery explosions.

yes, this is what missed in my tests

[+Crusader]

More on the J/N/P variants

AIM-9J (original version), 1970-1983 (approx. date of conversions finished)

AIM-9J-1 (original version, USAF improved variant introduced in 1977, then renamed to AIM-9P in 1978

Will only be available as AIM-9P in game, from 1977 (I try to simplify as much as possible..)

AIM-9J-1 (new version) from 1979 with new optical fuze

AIM-9J-2 new upgraded version with SR116 motor and old influence fuze

AIM-9J-3 new upgraded version with SR116 motor and optical fuze

I set the start date for them to 1980, thats about the time when supplies the new components became available

The availability of the new motor and fuze lead to a complete new set of new and upgraded J/N/P missile variants.

Existing stocks of AIM-9J could be upgraded to AIM-9N (Danemark N-2, Belgium N-3, more for other NATO members (Spain)). The 9N has the same variants like the new 9J series, but the Guidance and Control Unit (GCU) was updated with all solid-state electronics. That made it better than the 9J GCU, but still not as good as the all-new 9P GCU.

The new-production 9P series - again same variants as 9J/N, with the additional AIM-9P-4 with all-aspect capability and improved seeker range(1986), and the AIM-9P-5 with a further improved GCU/seeker for better range/guidance(1989). P-4/P-5 are the only versions with the electronics for SEAM mode and seeker look angle feedback.

All E/J/N/P series GCU's have electric-powered cooling, P-4/5 inclusive.

 

To be continued..

EDIT

Edited September 30, 2020 by Crusader

[+strahi]

Any news for AIM-9X and AIM-7,AIM-120 series?