How to use TWS mode for Su27/33

[Gault05]

I've heard that the Su27 and 33 are capable of using TWS on their radar, but I wonder how does it work exactly as opposed to its RWS counterpart. I've never got to really try it out due to the standard weapon loadouts they carry.

[draconus]

From the manual, p. 53-54:

Quote

 

"СНП" (TWS) MODE
Another BVR combat mode is "СНП" (Track-While-Scan or TWS). It is activated from the "ОБЗ" (SCAN) mode by pressing [RAlt-I]. The radar can correlate tracks for up to 10 targets simultaneously in "СНП" (TWS). The main distinction from SCAN mode is that the radar retains target parameters, like elevation and velocity vector, while continuing to search for additional targets.

The HDD provides a top-down view of the tactical situation including all tracked targets, together with their direction of travel and position.
TWS mode provides automatic target lock on (transition to STT). This is enabled by moving the radar cursor over a target. The cursor will "snap" to the target and follow it thereafter. Automatic lock on occurs at a range equal to 85% of the calculated maximum weapon launch range. The pilot can force an earlier lock on by pressing the [Enter] key.

 

So it's mostly different radar mode but the weapon use is the same (needs STT).

[Gault05]

Ah, okay then. So it's essentially a tracking mode for the semi-guided weapons until it locks on(or until the pilot deems the lock necessary). Thanks.

[Pavlin_33]

It's good for keeping a soft lock on a target without them getting alerted.

[AeriaGloria]

On 9/4/2024 at 10:25 AM, Gault05 said:

Ah, okay then. So it's essentially a tracking mode for the semi-guided weapons until it locks on(or until the pilot deems the lock necessary). Thanks.

It helps keep SA around the target before you get into weapons range 

[Skuva]

I only wish ED would make it not autolock the targets as soon as it get inside wez.

[AeriaGloria]

6 hours ago, Skuva said:

I only wish ED would make it not autolock the targets as soon as it get inside wez.

The real thing works the same. However, it will also automatically soft lock the target with higher proportion of cluster rate/range, which we don’t have in DCS and have to manually tag the radar connect with TDC 

[Skuva]

1 hour ago, AeriaGloria said:

The real thing works the same.

I'm really pressing the "Doubt" button on that. It makes no sense and serves no purpose. So if a pilot wanted to use TWS for any target closer than 40km he would either need to change to a closer range missile (I personally just leave at the R-73 and change it in the last second) or turn off the weapons system (or even worse, jettison all his weaponry)?

On top of that, in DCS most of the times the aircraft atempts to auto-lock it just loses lock immediatly (specially the Mig-29) and then you need to move TDC again over the target, and don't even get me started on AI that insta-jamm you on lock and puts you back into default radar settings (SCN + MED).

EDIT: This is all specially infuriating on the 29S, when you are trying to launch the R-77 at 2 targets but the thing decides to just lock the first target instead of soft-locking the second one.

Edited October 8, 2024 by Skuva

[AeriaGloria]

2 hours ago, Skuva said:

I'm really pressing the "Doubt" button on that. It makes no sense and serves no purpose. So if a pilot wanted to use TWS for any target closer than 40km he would either need to change to a closer range missile (I personally just leave at the R-73 and change it in the last second) or turn off the weapons system (or even worse, jettison all his weaponry)?

On top of that, in DCS most of the times the aircraft atempts to auto-lock it just loses lock immediatly (specially the Mig-29) and then you need to move TDC again over the target, and don't even get me started on AI that insta-jamm you on lock and puts you back into default radar settings (SCN + MED).

EDIT: This is all specially infuriating on the 29S, when you are trying to launch the R-77 at 2 targets but the thing decides to just lock the first target instead of soft-locking the second one.

 

Press doubt all you want, or don’t believe me, but it is true and what every MiG-29 and Su-27 manual will say. Here’s some examples 

“For SNP (track while scan) this case, automatic strobing of the target (when there are several targets it chooses the most dangerous),  and automatic engagement (locking) at distances close to the missile launch distances are provided, which favors the speed of execution and secrecy of the attack“

“ in TWS, According to the logic adopted in the targeting computer, the target with which the fighter has the shortest approach time is considered the most dangerous, and its mark on the HUD screen is automatically framed by a strobe and subsequently followed by it until the radar goes into acquisition mode. The computer calculates the zones of permitted launches of guided missiles for the conditions of attacking a the target. When approaching the current range mark and the maximum permitted launch range mark, the RLPK-293 complex automatically switches to the acquisition mode. Approaching the target in the TWS mode to the range of the missile engagement zone increases the stealth of the attack on the selected target.”

1. Design choices often don’t make “common sense,” and using it as a filter for what something might/should do can often lead to issues when context is lacking, especially with these complex military aviation birds. For example IRL, IRST/radar interaction is extremely limited in MiG-29 for seemingly no reason, yet works flawlessly and automatically in Su-27 

As mentioned above, the idea was to allow the pilot to select the most dangerous contact, keep situational awareness of the surrounding area, and only lock right before weapon firing for minimal warning to the enemy 

2. You say pilot couldn’t use TWS at close range with R-27,  but this isn’t true. Not only is R-27 can have a range as low as 4-5 km in rear aspect at low altitude. But if you were in situation where it has 40-50 km range and was closer then that, what would happen is the radar would enter TWS, see the most dangerous contact after a search cycle, then lock it if within missile range. There is no need to change weapon, jettison, or turn off missiles.

If they want to scan the area without locking, this is exactly why there is a switch to turn TWS off. The mode works fine at any range, and nothing stops you from turning it off if you don’t like it. The plane is not forcing you to use it 

And in DCS, there is no automatic target selection. So you can enter TWS at any range without automatic lock unless you physically place the TDC over the target or the target flies into it. 
 

3. Yes, TWS does not work with jamming. I have no problem using it to lock an unjamming target. If they turn on their jammer the mode automatically returned to regular search/scan mode. Yes you might need to reselect target, but likely you will only need to do it once since the pilot should be aware that TWS won’t work with jamming  

So yes, with jamming you need to use normal search and are limited to one target in case of MiG-29S. This is a technical limitation, it’s not like they intentionally designed it that way 

Technology has limits, and the designers believed that TWS would be helpful to minimize the time the target’s RWR see’s a STT signal and increase SA. And that if it sees jamming it reverts to normal scan so you can still search normally, since TWS requires more processing power then it can handle while jamming. Player F-16/18 has lock breaking jammer, and there is good reason it was decided to equip those planes with it. Hopefully someday FC3 jammers can get the same treatment 
 

Is there still an issue? 

Edited October 9, 2024 by AeriaGloria

[Skuva]

15 hours ago, AeriaGloria said:

Press doubt all you want, or don’t believe me, but it is true and what every MiG-29 and Su-27 manual will say. Here’s some examples 

“For SNP (track while scan) this case, automatic strobing of the target (when there are several targets it chooses the most dangerous),  and automatic engagement (locking) at distances close to the missile launch distances are provided, which favors the speed of execution and secrecy of the attack“

“ in TWS, According to the logic adopted in the targeting computer, the target with which the fighter has the shortest approach time is considered the most dangerous, and its mark on the HUD screen is automatically framed by a strobe and subsequently followed by it until the radar goes into acquisition mode. The computer calculates the zones of permitted launches of guided missiles for the conditions of attacking a the target. When approaching the current range mark and the maximum permitted launch range mark, the RLPK-293 complex automatically switches to the acquisition mode. Approaching the target in the TWS mode to the range of the missile engagement zone increases the stealth of the attack on the selected target.”

These paragraphs come from the 29A combat manual:

I can understand the first variants, that had the main role of GCI Interception while having easy operation in mind, getting such a feature. But neither the Su-27SK's flight and technical manuals mention this "automatic switch", even though it mentions all the other stuff like priority target logic, auto-boxing and general TWS functionality with both PRF modes:

And It would be reasonable to think, given the different role of the Su-27, it would be more focused on independent interception features, and not having the pilot flying and finding targets on such a on-rails manner as the MiG-29A.

It is even more confusing when looking at the J-11 and MiG-29S, which supposedly were upgraded with fox-3's and BVR in mind, why would they program it to not give any room for the pilot to choose, switch and lock targets at will in TWS? Meaning if there is a single aircraft unknowingly flying inside your WEZ, you are unable to use TWS to track any other aircraft, because it would prioritize that target, auto-box it and then imediately auto-lock it?

 

15 hours ago, AeriaGloria said:

2. You say pilot couldn’t use TWS at close range with R-27,  but this isn’t true. Not only is R-27 can have a range as low as 4-5 km in rear aspect at low altitude. But if you were in situation where it has 40-50 km range and was closer then that, what would happen is the radar would enter TWS, see the most dangerous contact after a search cycle, then lock it if within missile range. There is no need to change weapon, jettison, or turn off missiles.

I'm not talking about 4-5km ranges, who would chase a target at that distance using TWS? I'm talking about the most common situation, flying high and detecting hot targets far away, thats where the R-27ER will normally have 40-50km range and you will be forced to switch to a smaller range missile if you just don't want to scream into the enemy's ears that you are locking them until you get closer to the optimal range, or if you just want to keep a soft-lock on a target that is changing altitude and not bother with constantly changing radar elevation in SCN mode.

On a historical note, I imagine this particular situation wasn't a perceivable problem back on the 29A because it would primarilly use the R-27R (even the manual you cited doesn't account for the ER), so the WEZ, being almost half of the ER's, would give no problem to the radar auto-lock as it has when it tries to auto-lock with the ER selected at these very long ranges.

 

15 hours ago, AeriaGloria said:

3. Yes, TWS does not work with jamming. I have no problem using it to lock an unjamming target. If they turn on their jammer the mode automatically returned to regular search/scan mode. Yes you might need to reselect target, but likely you will only need to do it once since the pilot should be aware that TWS won’t work with jamming  

I know TWS is not suposed to work when jammed, I'm just saying that adds insult to injury with the current AI bad ecm modelling.

Edited October 9, 2024 by Skuva

[Pavlin_33]

On 10/8/2024 at 4:41 PM, Skuva said:

I only wish ED would make it not autolock the targets as soon as it get inside wez.

Switch to R-73s and it will not lock.

I use it all the time 'cause the NATO drivers don't pay attention to Soviet radars unless they are being hard-locked.

Edited October 9, 2024 by Pavlin_33

[AeriaGloria]

On 10/9/2024 at 8:16 AM, Skuva said:

These paragraphs come from the 29A combat manual:

I can understand the first variants, that had the main role of GCI Interception while having easy operation in mind, getting such a feature. But neither the Su-27SK's flight and technical manuals mention this "automatic switch", even though it mentions all the other stuff like priority target logic, auto-boxing and general TWS functionality with both PRF modes:

And It would be reasonable to think, given the different role of the Su-27, it would be more focused on independent interception features, and not having the pilot flying and finding targets on such a on-rails manner as the MiG-29A.

It is even more confusing when looking at the J-11 and MiG-29S, which supposedly were upgraded with fox-3's and BVR in mind, why would they program it to not give any room for the pilot to choose, switch and lock targets at will in TWS? Meaning if there is a single aircraft unknowingly flying inside your WEZ, you are unable to use TWS to track any other aircraft, because it would prioritize that target, auto-box it and then imediately auto-lock it?

 

I'm not talking about 4-5km ranges, who would chase a target at that distance using TWS? I'm talking about the most common situation, flying high and detecting hot targets far away, thats where the R-27ER will normally have 40-50km range and you will be forced to switch to a smaller range missile if you just don't want to scream into the enemy's ears that you are locking them until you get closer to the optimal range, or if you just want to keep a soft-lock on a target that is changing altitude and not bother with constantly changing radar elevation in SCN mode.

On a historical note, I imagine this particular situation wasn't a perceivable problem back on the 29A because it would primarilly use the R-27R (even the manual you cited doesn't account for the ER), so the WEZ, being almost half of the ER's, would give no problem to the radar auto-lock as it has when it tries to auto-lock with the ER selected at these very long ranges.

 

I know TWS is not suposed to work when jammed, I'm just saying that adds insult to injury with the current AI bad ecm modelling.

 

The pilot can choose. If they don’t like the selection, they can move the TDC to change it. It has to complete one full scan cycle before it can auto gate the target, determine missile engagement range, and then switch to STT which also takes multiple seconds (IRL). That gives the pilot 3.5 seconds to move the cursor as they like even just during that first scan. You have an unlock button if you want to undo switch to STT. 
 

I am not trying to talk only short ranges, I am just saying that TWS, in essence, is not your main weapon engagement mode for this radar! This is not like F-14/15/16/18. If you really want to kill someone that your radars detects, you use scan and go STT if all other methods fail. It is designed to attack one target at once, yes the computer could be upgraded for TWS2 and Fox 3. Pairing it with TWS2 is nice, and yes its susceptibility to jamming sucks, but if that fails you do what any MiG-29/Su-27 should do and lock the sucker and fire a missile one by one. It is the most reliable targeting method, and I can’t fault the engineers for not building in more substantial multi target track 
 

I do not believe that the engineers of N-019/19M/001 were trying to make the best thing to attack two planes at once, they were making the best radar they could to attack one target at a time. You do not need to use TWS, TWS2 if you don’t want to auto lock. And the featured TWS/TWS2 where the most dangerous target is auto magically gated by the TDC is not even in DCS! You don’t have to soft lock a target you don’t want to in DCS today unless you accidentally move the TDC over them or they fly into it. 
 

In Su-27, you have a nice datalink to show you more then one other enemy, so you need TWS for SA even less in that airframe. 
 

They made it to shoot one target as well as it could, and when MiG-29S upgrade came around they finally had the processing power to add a nice double target mode that has limits. Is it sad that everything they could’ve achieved didn’t happen because of lack of cost or political issues? Yes, yes it is. It is sad, but everything they have done I think they had good reason for, and made sure it could at least prosecute one target very well, the same as had been done with all previous Soviet mechanical scan array radars. 

Edited October 10, 2024 by AeriaGloria