Combat Tree?

[carss]

Ever heard of the Combat Tree? a supposed top secret capability the Phantoms possessed way back during Vietnam. It was basically an IFF system of sorts and would allow Phantoms to engage without VIDing the target. I was wondering if this capability could be included in the module too?

Here is a link about it..... https://tacairnet.com/2017/01/02/how-combat-tree-made-the-f-4-phantom-ii-the-deadliest-fighter-over-vietnam-in-the-1970s/

[SgtPappy]

38 minutes ago, carss said:

Ever heard of the Combat Tree? a supposed top secret capability the Phantoms possessed way back during Vietnam. It was basically an IFF system of sorts and would allow Phantoms to engage without VIDing the target. I was wondering if this capability could be included in the module too?

Here is a link about it..... https://tacairnet.com/2017/01/02/how-combat-tree-made-the-f-4-phantom-ii-the-deadliest-fighter-over-vietnam-in-the-1970s/

I was wondering about this as well. That's a good article that explains exactly what it is too. I've heard F-14's had it at one point as well (maybe they all had it). 

The F-4E's that arrived in Vietnam in November 1972 were mostly fitted with it in addition to TISEO. HB said they're making an F-4E from that time period but not sure if both those mods I mentioned will make it into the upcoming F-4E's since not all of them from that time period had these systems. If we do get it, I can see the F-4 being pretty powerful since other aircraft of the time period would basically need VID, as far as I'm aware. 

Do our MiG-21's have one of the transponders that would be vulnerable to this system? I admittedly have not flown it enough to know.

[upyr1]

13 hours ago, carss said:

Ever heard of the Combat Tree? a supposed top secret capability the Phantoms possessed way back during Vietnam. It was basically an IFF system of sorts and would allow Phantoms to engage without VIDing the target. I was wondering if this capability could be included in the module too?

Here is a link about it..... https://tacairnet.com/2017/01/02/how-combat-tree-made-the-f-4-phantom-ii-the-deadliest-fighter-over-vietnam-in-the-1970s/

I don't believe the Vietnam era E would have the combat tree, I could be wrong. The 1980s E would have something like that or better. I believe the first Phantoms with the system were Ds.

[divinee]

4 hours ago, upyr1 said:

I don't believe the Vietnam era E would have the combat tree, I could be wrong. The 1980s E would have something like that or better. I believe the first Phantoms with the system were Ds.

That’s what i’ve also read. Only some D’s had combat tree in Vietnam. Though the information is quite limited so i’m not 100% sure..

[SgtPappy]

8 minutes ago, divinee said:

That’s what i’ve also read. Only some D’s had combat tree in Vietnam. Though the information is quite limited so i’m not 100% sure..

In general, you're right. Most E's did not have them. However, as of November, 1972 under program "Rivet Haste", F-4E's with slats, cockpit ergonomics mods, long gun muzzles and TISEO arrived. Some of them had Combat Tree and these Phantom crews which trained together saw many many sorties, firing the first Mavericks in anger (most sorties were air-to-ground, 600 hrs or 600 sorties or so I forget the number) before the US left in 1973. They encountered MiGs on at least 3 occassions but their Sparrows missed.

Edited January 30, 2022 by SgtPappy

[divinee]

10 hours ago, SgtPappy said:

In general, you're right. Most E's did not have them. However, as of November, 1972 under program "Rivet Haste", F-4E's with slats, cockpit ergonomics mods, long gun muzzles and TISEO arrived. Some of them had Combat Tree and these Phantom crews which trained together saw many many sorties, firing the first Mavericks in anger (most sorties were air-to-ground, 600 hrs or 600 sorties or so I forget the number) before the US left in 1973. They encountered MiGs on at least 3 occassions but their Sparrows missed.

 

Thank you for the correction. Yeah I was familiar with the Rivet Haste, but i haven't found info about the Combat Tree in Rivet Haste program and that information seems to be under the rock . Can you share some sources where I can read more about those?

[SgtPappy]

I only have this one source after researching as much as I could on the Rivet Haste birds a couple years back. I haven't been able to find the original quoted report in full. I got it from http://www.aviationbanter.com/showthread.php?t=5985 

From the summary page of a report titled, "TAC Project 72A-068F: Rivet
Haste SEA Intoduction (U) Final Report" dated April 1973

"The introduction team was in place at Udorn Royal Thai Air Force
Base, Thailand, from 12 November 1972 to 12 January 1973. The 20 Rivet
Haste aircraft and aircrews were integrated into the 555th Tactical
Fighter Squadron of the 432d Tactitcal Reconnaissance Wing and
consisted of all Block 48 F-4E air superiority aircraft.

During this period of introduction, the Rivet Haste aircraft flew 238
combat sorties for a total of 643.6 combat hours..."

The 20 jets did NOT show up in one wave.

The first increment of 6 Rivet Haste aircraft arrived at Udorn on 20
November...first in-theather flights were flown on 24 November. [note:
none of these 6 had APX-81 Combat Tree]

Second batch of 6 Rivet haste arrived thusly...5 on 18 December 1972,
and number 6 the following day, 19 December (delay was due to radio
failure departing George AFB with the others). All 6 jets had Combat
Tree.

Last batch of 8 arrived at Udorn on 13 January 1973. Only 4 of the 8
had Combat Tree.

As stated above, the first combat mission was 24 November 1972. There
were ONLY three MiG engagements by Rivet Haste jets.

The first was on 22 December by a non-Tree jet, at night , closed to
within 4000' but could not get clearance to shoot.

Second was a during the day, the MiGs popped in and out of clouds
before a shot could be taken. [I infer a VID shot criteria, probably
due to numbers/proximity of radar contacts.]

The last was also at night, during a tail chase a max range AIM-7 shot
was taken...no luck. This was the ONLY missile shot by a Rivet Haste
jet.

[upyr1]

18 hours ago, divinee said:

That’s what i’ve also read. Only some D’s had combat tree in Vietnam. Though the information is quite limited so i’m not 100% sure..

You are right which is why I hope that if/when we get the D they have one with and one without 

[divinee]

5 hours ago, SgtPappy said:

I only have this one source after researching as much as I could on the Rivet Haste birds a couple years back. I haven't been able to find the original quoted report in full. I got it from http://www.aviationbanter.com/showthread.php?t=5985 

From the summary page of a report titled, "TAC Project 72A-068F: Rivet
Haste SEA Intoduction (U) Final Report" dated April 1973

"The introduction team was in place at Udorn Royal Thai Air Force
Base, Thailand, from 12 November 1972 to 12 January 1973. The 20 Rivet
Haste aircraft and aircrews were integrated into the 555th Tactical
Fighter Squadron of the 432d Tactitcal Reconnaissance Wing and
consisted of all Block 48 F-4E air superiority aircraft.

During this period of introduction, the Rivet Haste aircraft flew 238
combat sorties for a total of 643.6 combat hours..."

The 20 jets did NOT show up in one wave.

The first increment of 6 Rivet Haste aircraft arrived at Udorn on 20
November...first in-theather flights were flown on 24 November. [note:
none of these 6 had APX-81 Combat Tree]

Second batch of 6 Rivet haste arrived thusly...5 on 18 December 1972,
and number 6 the following day, 19 December (delay was due to radio
failure departing George AFB with the others). All 6 jets had Combat
Tree.

Last batch of 8 arrived at Udorn on 13 January 1973. Only 4 of the 8
had Combat Tree.

As stated above, the first combat mission was 24 November 1972. There
were ONLY three MiG engagements by Rivet Haste jets.

The first was on 22 December by a non-Tree jet, at night , closed to
within 4000' but could not get clearance to shoot.

Second was a during the day, the MiGs popped in and out of clouds
before a shot could be taken. [I infer a VID shot criteria, probably
due to numbers/proximity of radar contacts.]

The last was also at night, during a tail chase a max range AIM-7 shot
was taken...no luck. This was the ONLY missile shot by a Rivet Haste
jet.

Thank you for the link. There seems to be quite a lot of good info

[SuperEtendard]

On 1/29/2022 at 11:41 PM, SgtPappy said:

Do our MiG-21's have one of the transponders that would be vulnerable to this system? I admittedly have not flown it enough to know.

Afaik the 21bis has an updated encripted IFF transponder, the MiG-19P has the old one so it should work on it.

[USA_Recon]

It was confirmed 

https://discord.com/channels/1071433028045377637/1108849721566576671/1353575614581444698
 

“combat tree is a feature of the E and it will eventually get it”

Zabuzard 3/24/25

[Zabuzard]

It was confirmed 
https://discord.com/channels/1071433028045377637/1108849721566576671/1353575614581444698
 
“combat tree is a feature of the E and it will eventually get it”
Zabuzard 3/24/25

Everything marked in the manual as "todo" will eventually come :)

Combat Tree is quite cool, but the very limited IFF-environment in DCS makes it challenging to implement it. (Currently you cant query any IFF info from other planes, such as if their transponder is turned on/off or what code etc.)

What we have in mind is implementing it similar to friendly-IFF, that is it will show you any hostile aircraft (based on faction) on your screen, just like it was IRL.
And then provide mission editors with options to either turn it off completely or a historic mode where it only works on certain planes that were equipped with the specific russian IFF transponders that the US were able to crack.

[Omega417]

So in future will we be able to ask Jester to "perform IFF" and have bandits appear on the radar screen for him to lock?

[Zabuzard]

7 hours ago, Omega417 said:

So in future will we be able to ask Jester to "perform IFF" and have bandits appear on the radar screen for him to lock?

Jester already performs IFF by himself constantly and you also can already ask him to IFF explicitly.

When Combat Tree is added, I am sure Jester will also operate it so you get to benefit from it - if that answers your question

[streakeagle]

In DCS World, IFF generally works perfectly, which negates the need for Combat Tree. In reality, when you used IFF, if you got a response, you pretty much knew for sure you had interrogated a friendly. But if you didn't get a response, that could mean it is an enemy or it could be that the contact's IFF failed to respond for a number of reasons or that your IFF failed to detect the response. So, IFF only gave you one of two IDs: friendly or unknown. But with Combat Tree, if your intel was good, you could interrogate and get an IFF response from the enemy. No friendly could respond to Combat Tree. So, Combat Tree gave you one of two IDs: enemy or unknown. But as far as I can tell, Jester is 100% successful with IFF. If he says it is an enemy, it is, so you don't need Combat Tree to improve your odds of correctly identifying the enemy.

Fast forward a few years and you have F-15s using NCTR: an advanced digital signal processor can tell the jet engine type from the frequency modulation of the radar return, much the same way a sonar technician classifies sonar contacts by demodulating their broadband signals to get screw/blade information and reduction gear ratios (I was a submarine sonar tech for 8 years and know all too well what you can do with blade/rate information). Now you don't need to emulate enemy IFF and have intel on his IFF settings. Just like Combat Tree, you either get unknown or positive ID: good enough to shoot.

[Dragon1-1]

8 hours ago, streakeagle said:

In DCS World, IFF generally works perfectly, which negates the need for Combat Tree.

It doesn't, sometimes the check seems to fail, in the Phantom, at least. Jester declares a bandit while in friendly airspace. It's also worth noting that some aircraft (friendly or otherwise) don't have IFF. Civilian ones, in particular, would never respond in Mode 4. This is rarely a factor in DCS, but occasionally it can be.

[Kalasnkova74]

9 hours ago, streakeagle said:

In DCS World, IFF generally works perfectly, which negates the need for Combat Tree.

Not in the F-4s case. Combat Tree enabled reliable passive ID of hostile targets beyond the APQ-120s detection range. Knowing who is or isn’t a bandit is a bonus. 

[Zabuzard]

Yeah. In a nutshell, Combat Tree allows you to "magically" spot any contact in like 200nm distance. Its like getting gods vision. You see them all, regardless of what your radar is doing. It is not only used to ID a target that you picked up with your radar, it allows you to actually locate bandits like a "super-radar".

Just like it was IRL for the Phantom pilots in the time period where Combat Tree was used and enemies have not patched their systems yet.

Its not "magic" ofc, but the IFF receiver/transponder have a much greater range.

Edited Tuesday at 11:28 AM by Zabuzard

[Dragon1-1]

In fact, that's the reason for Mode 4 on Western aircraft. Modes 1, 2 and 3 are not encrypted, so anyone could do that sort of thing by simply interrogating them. If you don't turn off those modes, anyone with an interrogator can see exactly where you are.

[Omega417]

On 5/2/2025 at 5:27 PM, Zabuzard said:

Jester already performs IFF by himself constantly and you also can already ask him to IFF explicitly.

When Combat Tree is added, I am sure Jester will also operate it so you get to benefit from it - if that answers your question

That does, I have IFF mapped to my throttle and have been playing around with having Jester IFF the sky if I know something is out in front of me but he doesnt see it on radar.

[Zabuzard]

27 minutes ago, Omega417 said:

That does, I have IFF mapped to my throttle and have been playing around with having Jester IFF the sky if I know something is out in front of me but he doesnt see it on radar.

Sorry, what are you trying to say? Combat Tree is not there yet, if that is what you thought.

[Omega417]

I know its not, before I chimed into the thread,  I was doing this constantly thinking it would make Mr. Jester realize there was something out there. Now I just use it to help me see my tankers on the scope when jester doesnt lock them up.