[INVESTIGATING]Weapons behavior on F-5E and MiG-21Bis

I did a exhaustive investigation about some typical weapons used on both platforms.

The first topic is about the seeker tone distance on rear and front aspect.

# TONE - REAR ASPECT

F-5E		MiG-21	
---------------------------------
R-55	1.53 nmi	2.21 nmi
R-60	1.78 nmi	2.56 nmi
R-3S	1.90 nmi	2.73 nmi
R-60M	2.41 nmi	3.46 nmi
R-13	3.56 nmi	5.18 nmi
R-13M1	3.58 nmi	5.19 nmi
R-3R	5.34 nmi 	5.34 nmi (RADAR GUIED)
RS-2US	5.34 nmi 	5.34 nmi (RADAR GUIED)

GAR-8	5800 ft 	1.38 nmi
AIM-9P	2.35 nmi	3.42 nmi
AIM-9P5	4.75 nmi	7.00 nmi

As you can see seems that the MiG-21 IR signature is almost the double than the F-5E, later will discuss a bit about this topic. Also the seeker distance seems a bit strange, look at R-13s, R-60M and AIM-9P5, something seems broken there.

# TONE - FRONT ASPECT

F-5E		MiG-21	
---------------------------------
R-55	4200 ft		4200 ft
R-60	4400 ft		4400 ft
R-13M	4400 ft  	4400 ft  (NOT GUIDING)
R-13M1	4500 ft  	4500 ft  (NOT GUIDING)
R-3S	4800 ft  	4800 ft  (NOT GUIDING)
R-60M	1.34 nmi	1.34 nmi
R-3R	5.15 nmi 	5.15 nmi (NOT GUIDING??)
RS-2US	5.15 nmi	5.15 nmi (RADAR GUIED)

GAR-8	0.00 nmi	0.00 nmi (NO TONE)
AIM-9P	0.00 nmi	0.00 nmi (NO TONE)
AIM-9P5	1.68 nmi	2.35 nmi

Ok, this is really strange. The R-3R seems to be "rear aspect" and from front it's unguided, like a rocket but the fuse works, the R-13M, R-13M1 and R-3S works the same (but on IR).

Now this is the effective current lethal range:

# RANGE - LETHAL

R-55	1.25 nmi
RS-2US	1.42 nmi
R-60	1.78 nmi
R-3S	1.86 nmi
R-60M	1.88 nmi
R-3R	2.02 nmi
R-13	2.10 nmi
R-13M1	2.33 nmi

GAR-8	1.38 nmi
AIM-9P	2.60 nmi
AIM-9P5	2.75 nmi

The ranges, also seems to be bad, the R-60 and R-60M range is too small.

Also I tried to know the maximum range on a pure heads-on, but I was unable to launch the soviet missiles without tone, and with tone, is always into the maximum range.

# RANGE MAXIMUM

RS-2US	3.26 nmi
R-3R	5.15 nmi
AIM-9P5	8.95 nmi (NO TONE IMPACT!!!)

Yes, the AIM-9P5 will impact a hot contact on front aspect at 9nmi WITHOUT TONE.

Now we will return to the IR signature. I don't have any IR image to confirm that, but the F-5E engine exhaust temperature at 100% RPM (without AB) is 550ºC for each engine (two engines) and the MiG-21Bis at same parameters is on 630ºC I doubt a lot that this can make a huge difference in favor of F-5E.

TL;TR

Maybe the Mig-21 IR signature is too high, the R-60 and R-60M seeker too bad, the R-13s too good on rear aspect and the AIM-9P5 can hit from a god-alike distance without tone.

F-5E_AIM9P5_WLOCK.trk

F-5E_AIM9P5_LOCK_F5.trk

F-5E_AIM9P5_LOCK_MIG21.trk

Very interesting investigation! I'm flying both planes for some years now but this thread has really opened my eyes!

For the R-60, the original non cooled variant someone in another thread posted these:

could be worth looking at. Additionally how are the IR signature values calculated? What do the values mean?

I can't say about MiG-21 IR signature because data files of 21 are cripted, but I can show what we have in the DCS for several aircraft.

 

Su-17

IR_emission_coeff = 0.69,

IR_emission_coeff_ab = 3,

Ok, is it possible to ask to LN about the MiG-21 values?

Also checking it, the Su-17 Lyulka AL-21F-3 engine is similar to the F-4 GE-J79 but using only one engine. Maybe this value is a bit high.

Why do you think so?

The R-60 OGS-60TI "Komar" seeker, had a conventional single colour scanning detector with a ±12..±17° (more like to ±12°) off-boresight capability and 35°/sec tracking rate. The R-60M OGS-75 "Komar M" seeker increased the off-boresight capability to ±20° and improved tracking rate. With this the Komar M seeker is a bit better than the AIM-9L seeker and the Komar, like the AIM-9P-4.

About the rocket solid fuel and engine, I don't have good sources, for this I will only estimate some data, knowing that the R-60 mass is 43.5kg with 3kg warhead, and for the R-60M the mass was increased to 45km and 42mm larger (probably all is fuel and fuselage) using the same fuel this can be a 106.15% burning time (the warhead and fuselage mass was already taken account), this also will increase the mid speed.

With this we will suppose that the ISP is around to 120s, with a burning time of 4s and an a rate of 5kg/s this means an a thrust of 5.884kN, using a full mass of 43.5kg and a dry mass of 23kg (3 for the warhead, 2 for the seeker, 18 for the fuselage and engine) will gave us an a dV of 750m/s that plus 150m/s plane speed is the same that the alleged 2.5 mach speed for the rocket. With this is easy to say a peak speed of 750m/s plus the plane speed at 4s burn time for the R-60 and 790m/s plus the plane speed for the R-60M.

IMHO, the current R-60 and R-60M implementation is very far from this estimated data, all is similar (burn time, mass rate, etc.) but the ISP is totally off with a peak speed at 4s of 460m/s plus plane speed.

To add to the topic: AIM-9P5 is smokeless, while the newer AIM-9L is not in DCS. Why so? Will this be corrected?

Yes. You can do it.

These engines are distinguished by thrust.

AL-21F has 110 kN

J79 has 80 kN

The IR fingerprint in DCS is according to thrust?

I thing the western technology in 9L and 9P-4/5 is a qute better then soviet Komar.

Soviet missiles have always tried to catch up with the American. An exception may be the R-73, which was very good for its time.

Ok, but the current seeker values are too low, the Komar M seeker detection is almost the half than the AIM-9P5 in DCS, and in reality is only a bit worse than the AIM-9L.

# TONE - REAR ASPECT

F-5E		MiG-21	
---------------------------------
R-60M	2.41 nmi	3.46 nmi
AIM-9P5	4.75 nmi	7.00 nmi

According to our estimates, the R-60 missiles in the DCS is very close to the his real prototype. We focused on Soviet documents on flight performance.

You can compare it by yourself.

 

R-60 motor impulse total = 3726 kN

Ok, replicating this chart in DCS it gave me these ground distances.

10km - 14.31km
5km  - 10.50km
1km  -  8.13km

This is a bit less than the attached chart. I attached tracks.

R60M_10km.trk

R60M_5km.trk

R60M_1km.trk

Yeah DCS's R60 performance in terms of kinematic range isn't awful, my own CFD results matched almost exactly with ED's current implementation so the range is good imo.

In terms of seeker range its hard to say i personally havn't seen anything saying DCS's representation of the R60/60M seekers are wrong in terms of range not this

Additionally:

I'm wondering does a chart like this exist for the SU-27? I'd base the relative range values off of how these charts compare to the baseline.

I know I've somehow been hit head on at probably a mile distance by a Mig21's R3. In tacview it just said R3, but I assume it was a radar missile?

Probably but it does seem it may be a bit buggy at the moment according to that other thread.

was it indicated if this value was max possible? Or was it more along the lines of max head on?

R-60 motor impulse total = 3726 kN

I was wrong.

It is impulse of R-3S missile.

 

R-60 and R-60M total impulse = 2452 kN.

We are all human and make mistakes.

It takes a man to admit a mistake has been made.

You Sir, Chizh, I shake your hand.

:beer:

Glad you are here interacting with the community to make DCS the best it can be / will be through this type of leadership you have displayed.

Thank you,

Monnie

I am guessing the MiG-21 afterburner heat signature disappearing bug also plays a part

It is maximum seeker range about 45 degree aspect angle, without any missile dynamic estimation.

Ok seems reasonable for a heli from that aspect, now of course in DCS as you noted this number is a bit high. Maybe something worth investigating is a rework of some of these values?

May I ask why the R-55 seeker is performing so bad? It is said to have the R-13 seeker, so should it not behave equally?

On 2/7/2020 at 6:55 PM, riojax said:

 

Ok, is it possible to ask to LN about the MiG-21 values?

 

Also checking it, the Su-17 Lyulka AL-21F-3 engine is similar to the F-4 GE-J79 but using only one engine. Maybe this value is a bit high.

 

 

 

 

The R-60 OGS-60TI "Komar" seeker, had a conventional single colour scanning detector with a ±12..±17° (more like to ±12°) off-boresight capability and 35°/sec tracking rate. The R-60M OGS-75 "Komar M" seeker increased the off-boresight capability to ±20° and improved tracking rate. With this the Komar M seeker is a bit better than the AIM-9L seeker and the Komar, like the AIM-9P-4.

 

About the rocket solid fuel and engine, I don't have good sources, for this I will only estimate some data, knowing that the R-60 mass is 43.5kg with 3kg warhead, and for the R-60M the mass was increased to 45km and 42mm larger (probably all is fuel and fuselage) using the same fuel this can be a 106.15% burning time (the warhead and fuselage mass was already taken account), this also will increase the mid speed.

 

With this we will suppose that the ISP is around to 120s, with a burning time of 4s and an a rate of 5kg/s this means an a thrust of 5.884kN, using a full mass of 43.5kg and a dry mass of 23kg (3 for the warhead, 2 for the seeker, 18 for the fuselage and engine) will gave us an a dV of 750m/s that plus 150m/s plane speed is the same that the alleged 2.5 mach speed for the rocket. With this is easy to say a peak speed of 750m/s plus the plane speed at 4s burn time for the R-60 and 790m/s plus the plane speed for the R-60M.

 

IMHO, the current R-60 and R-60M implementation is very far from this estimated data, all is similar (burn time, mass rate, etc.) but the ISP is totally off with a peak speed at 4s of 460m/s plus plane speed.

 

source?

On 7/3/2023 at 5:11 PM, Smoak741 said:

source?

- Seeker info: Doug Richardson (Janes Missiles and Rockets) in his article “Iraqi heat-seeking Gainfuls found”
- Rocket info: me