DCS: F-14 Development Update - AIM-54 Phoenix Improvements & Overhaul - Guided Discussion

[draconus]

17 minutes ago, Predator-78 said:

The Phoenix in particular is quite complex, I understand that it is a missile created to hit high-altitude bombers, but is it effective against small fighters? I also didn't understand after the launch where to look to see that the missile went into Pitbull.

When you launch the AIM-54 in TWS you can see a counter near the target symbol on TID repeater. When it starts blinking it means the WCS has sent the signal to go active.

Phoenix is capable of shooting down fighters but it's effectiveness depends on shooting parameters (range, speed, altitude, attitude), target parameters (speed, altitude, attitude), target maneuvering/defending and countermeasures (ECM, chaff).

[Tweety777]

The phoenix is definitely useful against fighters as well, though the seeker head is not on par with that of the AMRAAM but due to it's range can be very hard to get rid off.

 

You can see if it turned Pitbull when the timer next to the target on the lower screen is flashing.

[Predator-78]

Thanks !!!

Inviato dal mio SM-G998B utilizzando Tapatalk

[Predator-78]

I have another question, when I lock with jester, the TID shows up like this, why? I have no way to view information...

[Comstedt86]

4 hours ago, Predator-78 said:

I have another question, when I lock with jester, the TID shows up like this, why? I have no way to view information...

Looks to me you are locking a jamming target and is too far away to burn through / and got no range information yet.

[Karon]

11 hours ago, Comstedt86 said:

Looks to me you are locking a jamming target and is too far away to burn through / and got no range information yet.

Brilliant answer!

The AI turn on their jammers the nanosecond you switch to STT in an attempt to confuse your avionics. This is not a problem between TCS and LINK4, though.

[tavarish palkovnik]

 

AIM-54 zone puska.pdf

 

[Machalot]

On 11/13/2023 at 4:14 AM, tavarish palkovnik said:

 

AIM-54 zone puska.pdf 3.09 MB · 23 downloads

 

I would guess the altitude grids are 10,000 ft and the Mach grids are 0.5.

[tavarish palkovnik]

 

I would take it as 0,4 M

 

Edited November 18, 2023 by tavarish palkovnik

[tavarish palkovnik]

This is how I see flight as per Figure No.7 could looks like, targeting high speed/high altitude ''Mig-25''

 

 

Missile usually after releasing is with small decline relatively to airplane axis, I gave it as negative 2 degeess. Then first 4 seconds after motor started, missile released starts its flight, after that I overloaded missile with constant 5g. That is red part of trajectory, and than missile is again released.

For velocity this overload has significant influence, 5g in 10 seconds is flight with angle of attack from 25 to 13 deg ->

 

   

 

For comparison, three cases, this one, horizontal constantly overloaded flight and ballistic shot with start elevation 30 deg

 

 

 

 

 

[tavarish palkovnik]

Check of mathematical model (with used like they wrote ''publicly available data'' , meaning here I used 13595 N / 27 sec), and comparison with famous NASA ''shots'' 45000ft ; 1,2M ; 0 / 30 / 45 deg

 

45000ft ; 45deg ; 1,2 / 0,8 / 0,5 M

 

 

It fits nice, only this thrust envelope has nothing related with real condition

 

 

[tavarish palkovnik]

Is there volunteer to simulate this situation in-game to see how it behaves? Most probably it will be a bit, or quite, most likely, different because basic postulates are different.

I didn’t mention, thrust envelope I’ve used is linear drop function from 26210 N (0+s) to 8418 N (25s) what makes total impulse of 432850 Ns or 97313 lbs. With drag coefficients I don’t occupy too much (don’t see those as over too much significant) so I always use Cx58 rule and for this situation I selected i58 as 1,2 for active and 1,5 for passive time (PS…numbers are not exact Cx numbers but factors relative to Cx58 numbers). And for lift coefficients in supersonic range, simple linear function (-0,03*M+0,26) 

Another case 72000ft/2,8M/50nm is also interesting as well as low flying target (Figure 10) 

 

Edited November 20, 2023 by tavarish palkovnik

[captain_dalan]

On 11/2/2023 at 5:07 PM, Katsu said:

 

 

 

Is the AIM-54A configured to hunt chaff instead of planes now?  

1.09 MB · 2 downloads Test 6 - 1 Kills.acmi 1.09 MB · 2 downloads Test 7 - 0 Kills.acmi 1.45 MB · 2 downloads Test 8 - 1 Kills.acmi 1.15 MB · 4 downloads Test 9 - 0 Kills.acmi 1.43 MB · 3 downloads Test 10 - 0 kill.acmi 1.39 MB · 3 downloads Test 1 - 0 kills.acmi 1.65 MB · 2 downloads Test 2 - 0 Kills.acmi 1.24 MB · 2 downloads Test 3 - 0 Kills.acmi 1.44 MB · 2 downloads Test 4 - 1 Kills.acmi 1.24 MB · 2 downloads

Yes, despite first hand accounts of the AIM-54A being more resistant to CM then contemporary Sparrows (we are talking pre AIM-54C era here), ED has decided to make them worse. Hooray! Just learn to live with it. We are living with UFO AI's and Unobtanium powered Hornets. Is it so hard to live with a Phoenix that prefers not to hit its targets? 

[tavarish palkovnik]

Another case, launch against super fast high altitude flying target

 

 

 

In two options, overload with 5g and 3g, and all is to be better with higher/shorter overload. It is nearly (almost) same time untill contact but terminal velocity is higher with 5g becuase missile would take a bit less dense atmosphere

[draconus]

19 minutes ago, tavarish palkovnik said:

Another case, launch against super fast high altitude flying target

I know these are theoretical cases but both in DCS and IRL it would be lofted shots.

[tavarish palkovnik]

2 hours ago, draconus said:

I know these are theoretical cases but both in DCS and IRL it would be lofted shots.

I will try to explain, with my poor English, this last scenario. This is loft, actually attempt to loft over such quick approaching target (in 55 seconds target travels 45,5 km). This starting 5g overload up there could be boundary condition for AIM-54, like said it is starting 25 degrees angle of attack for missile. Theoretically with overload >5g missile could in this scenario go over target altitude, with significant velocity shock performing such maneuver. And that is not all, to avoid situation that target slips under, missile should perform one more overloaded maneuver, now with negative angle of attack which will take additional velocity potential. Two such maneuvers will result with terminal velocity for sure less than managed 2,8M as presented.

Eventually, if airplane will be in moment of launch with some elevation angle relatively to horizon, and by that missile in start will not need to handle with initial pushing nose from downward to upward, having starting elevation angle in opposite direction to what loft is looking for.

And honestly, I’m not sure airplanes like F-14 made real launches of missiles like AIM-54 at such altitudes flying overloaded, flying with height gain, flying with axis elevated relatively to horizon. 

If this scenario would be with target flying a bit lower than these 22km and slower than these insane 2,8M, missile would go with this 5g in visually full blooded loft. However, these two sample shots are everything but not standard shots.

[draconus]

4 hours ago, tavarish palkovnik said:

This is loft, actually attempt to loft over such quick approaching target...

No, this is only manual loft by aircraft pitch - the missile is programmed to loft - meaning to fly the lobbed path by using the high thin air for most of its flight.

Here's how it looks in DCS (and how would it fly during combat IRL). A bit different launch numbers due to radar/Jester and Mission Editor limitations.

AIM-54A Mk47 test MiG-25.trk

[tavarish palkovnik]

We didn't understand each other well, these shots of mine are not shots with elevation (airplane pitch) but shots from horizontal fly and red parts of trajectory are parts where missile is overloaded, missile performs loft alone by its energy as it should be.

Also this sample you made is not case we have. Launch range is 50nm (92,6km) , distance between fighter and target in moment of launch. Shot range in that case is something about 25 nm (46km) measured from starting point and that for me is point of launch. It is fligth time for missile of only 55 seconds  or something like that

[draconus]

44 minutes ago, tavarish palkovnik said:

Launch range is 50nm (92,6km)...

Yeah, my bad, I lost it with all these unit conversions. I was trying to do the exact 92nm shot but Jester refused to STT the MiG, only seconds later he was able to do it.

But it's not worthless. You can see that the missile at 01:34 (that would be 55s of missile flight) is easily over 94k ft (28km) without any struggle, in very high energy state - M2.8. Of course the profile for 50nm will be different but still not that flat - maybe another time.

[tavarish palkovnik]

Thanks @draconus for time and efforts. If you manage to find some extra time, try to make this exact shot and I’m pretty sure there should not be some significant or any loft.

I know in game lot of things are simplified, when I make some specific trajectory I put “in machine” program which makes integrating of mostly all mutually linked factors…and missile simply doesn’t like  to go in loft.

 

[draconus]

4 hours ago, tavarish palkovnik said:

If you manage to find some extra time, try to make this exact shot and I’m pretty sure there should not be some significant or any loft.

Well, it did slightly loft as expected.

AIM-54A Mk47 launched from F-14B ~M1.2 41000ft vs Mig-25PD (AI) flying straight and level ~M2.8 65600ft (Mission Editor limit, sorry).

Flight time: 69s
Max: 5G, 40° pitch, alt 72400ft, then glided down to target.

 

AIM-54A Mk47 test MiG-25 50nm.trk

Edited November 22, 2023 by draconus

[FWind]

[tavarish palkovnik]

This one was tough but after several attempts I manged to get it flies that way

 

 

 

It was all about when, how and how much to overload missile

 

 

This is how Cx and Cy change with time

 

 

Motor of course is not Spoonge Bob form but more as it should be

 

 

 

This is change of dynamic pressure with time

 

 

And at the end how trajectory looks like

 

 

Of course this has nothing related with original Phoenix, NASA planned to use it for other purposes. 

[tavarish palkovnik]

Finding answers how Phoenix’s motor actually looked and worked was with lot of fun. 
Is there some other motor of US or Russian origin which might be interesting, or which is with questionable current numbers, to strip it down in free time reserved for nerve relaxation 

[GGTharos]

It would be nice to analyze AIM-7 motor.