'Combat Tree '- info sought about

64 views
Skip to first unread message

Jon W

unread,
Jan 30, 1999, 3:00:00 AM1/30/99
to
Reportly a Vietnam era (c 1972) fighter bourne electronic long distance
method of identification of friend or foe.

Anyone any further info on what is was and how it worked?


jon


g_al...@hotmail.com

unread,
Jan 30, 1999, 3:00:00 AM1/30/99
to
In article <36B31D...@dial.pipex.com>,

According to now declassified U.S. sources, Combat Tree was an IFF
interrogator that could interrogate MiG IFF transponders. It was first
installed on a small number (8?) of F-4Ds in late'71 or so, which were
operated by the 432nd TRW (The serial numbers are given in Anthony
Thornborough's "The Phantom Story"). I've checked his list against the Red
Baron reports, which identify whether and which a/c in a flight are Combat
Tree equipped and which contacts were due to Combat Tree, and cross-checked
those incidents with listings of those kills which include the a/c serial
numbers. They match).

Because of the small numbers available, typically only the flight lead (01)
and (when available) the element lead (03) would be in 'Tree'-equipped birds.
02 and 04 were often in F-4Es, to provide some gun capability without
forcing the F-4Ds to carry gun pods. Because of the loss of several of these
a/c, some more (about 20?) were modified in mid '72 (available July, I
think). Later, when the Rivet Haste slatted F-4Es showed up in theater to
re-equip the 555th, they were apparently all equipped with it.

Combat Tree had several positive effects. First, it allowed U.S. fighters to
acquire MiGs at much greater ranges than they could from a primary return
(i.e. a skin paint). Second, it allowed them to make contact looking down in
many cases. This meant that free-roving MiGCAPs were much more effective
than they had been; previously, the NVn would just vector there MiGs around
U.S. MiGCAPs by keeping them low until they'd gotten out of our a/c's radar
arcs. It also meant that we were allowed to take more BVR shots with the
AIM-7 than we'd previously been able to. An example the initial engagement
of Oyster flight on 10 May 1972. Lodge in 01 and Ritchie in 03 were both
flying Tree-equipped a/c, and Lodge's and Markle's kills were both fired BVR
because of a Combat Tree ident.

It wasn't perfect. There were limits as to how close a Tree contact could be
to other a/c, before a BVR shot was allowed. In at least one case, an a/c
ID'ed as a MiG by Tree was visually ID'ed by TISEO gear as an F-4,
fortunately before a shot was taken. In addition, the NVN was montitoring our
radio coms. When our pilots started to report contacts on MiGs at previously
unheard of ranges, they started to get suspicious, and curtailed their use of
transponders, only turning them on at turn points or the like instead of
using them continuously as they had previously.

For the best, most accessible discussion of Combat Tree, QRC-248 (a similar
interrogator installed on board the EC-121s from 1967; Michel, quoting from a
declassified document, says theat QRC-248 would tyypically allow an EC-121
Connie which might have trouble detecting a MiG at 100nm at medium altitude,
to detect them at 175nm at low altitude) and the rest of the Vietnam air
campaign, you should find a copy of "Clashes," by Marshall Michel (sp?).
This is based on declassified U.S. documents now available from the
Historical Research Center in the archives at Maxwell AFB, checked by
Michel's own experience. The HRC has a website listing some of what's
available, although it tends to be a bit out of date, and last time I
checked, none of it was on-line; yopu have to order the stuff by mail, or go
there. I have a friend who works there, and he's made copies for me.

I got my copy of "Clashes" from amazon.com for 30% off a year or two ago,
when it was published. If you're interested in how an air campaign is
fought, this is one book you've got to have. Another excellent book for
details of the F-4's weapons is the one by Thornborough mentioned above.

Guy

-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own

Dweezil Dwarftosser

unread,
Jan 30, 1999, 3:00:00 AM1/30/99
to
On Sat, 30 Jan 1999 14:54:52 +0000, Jon W <xw...@dial.pipex.com> wrote:

>Reportly a Vietnam era (c 1972) fighter bourne electronic long distance
>method of identification of friend or foe.
>
>Anyone any further info on what is was and how it worked?

Yes, there's lots of info. However, last I heard, most of it was
still classified.

- John T.

Roderick Horton

unread,
Jan 30, 1999, 3:00:00 AM1/30/99
to
What do you want to know about IFF. I will replay being that I am a former
IFF technician..
AN/APX64 AN/APX 72 AN/APX 76 AN/APX/118 AN/APX VERY CLASSIFIED...

All you have to do is ask and I will respond.. unfortunately my replies
will be in the form of CLASSIFIED
CLAssified and Classified..
Dweezil Dwarftosser wrote in message
<36b35625...@news.rdu.bellsouth.net>...

Dweezil Dwarftosser

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
On Sat, 30 Jan 1999 19:56:41 -0600, "Roderick Horton"
<Cwoh...@yahoo.com> wrote:

>What do you want to know about IFF. I will replay being that I am a former
>IFF technician..
>AN/APX64 AN/APX 72 AN/APX 76 AN/APX/118 AN/APX VERY CLASSIFIED...
>
>All you have to do is ask and I will respond.. unfortunately my replies
>will be in the form of CLASSIFIED
>CLAssified and Classified..

This is an inappropriate forum for such a discussion.

- John T.

SteveM8597

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
>It was first
>installed on a small number (8?) of F-4Ds in late'71 or so, which were
>operated by the 432nd TRW (The serial numbers are given in Anthony
>Thornborough's "The Phantom Story"). I've checked his list against the Red

Historical note. The "Tree: birds were first assigned to the 475th later 3rd
TFW operating out Misawa and Kunsan. They were deployed to the 432nd in Mar 72
during the Easter Offensive. They were apparently immediately successful with
kills as soon as they arrived in theater, though I heard one was shot down
shortly after its arrival. If I am not mistaken, one of the Wright Patterson
AFB F-4D gate guards (554, don't recall the rest) was a tree bird. It has two
kills to its credit. Not sure how much is stillclassified, but I will say that
from an aircrew standpoint, it was a very effective and capable piece of gear,
unlike some of the electronic systems in the F-4 (RHAW) to name one.

Matt Clonfero

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
In article <36B31D...@dial.pipex.com>, Jon W <xw...@dial.pipex.com>

wrote:
>Reportly a Vietnam era (c 1972) fighter bourne electronic long distance
>method of identification of friend or foe.
>
>Anyone any further info on what is was and how it worked?

IIRC it polled the IFF units fitted to North Vietnamese Air Force
aircraft. Getting a positive Combat Tree reading was sufficient
identification to engage with Sparrow, instead of having to wait for a
visual ID.

Aetherem Vincere
Matt
--
Matt Clonfero: Mat...@aetherem.demon.co.uk | To err is human, To forgive
My employer and I have a deal - I don't speak | is not Air Force Policy.
for them, and they don't speak for me. | -- Anon, ETPS.

Roderick Horton

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
That is why my replies are Classified...Did I say Tool shop..?

Dweezil Dwarftosser wrote in message
<36b40b76...@news.rdu.bellsouth.net>...

Tex Bennett

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
On Sun, 31 Jan 1999 18:03:35 +0000, Matt Clonfero
<Ma...@aetherem.demon.co.uk> wrote:

>In article <36B31D...@dial.pipex.com>, Jon W <xw...@dial.pipex.com>
>wrote:
>>Reportly a Vietnam era (c 1972) fighter bourne electronic long distance
>>method of identification of friend or foe.
>>
>>Anyone any further info on what is was and how it worked?
>
>IIRC it polled the IFF units fitted to North Vietnamese Air Force
>aircraft. Getting a positive Combat Tree reading was sufficient
>identification to engage with Sparrow, instead of having to wait for a
>visual ID.

Sound similar to the "Serrate" kit fitted to NF Mosquitos that
escorted the RAF Night Bombers later in WW2.
It triggered the IFF sets Luftwaffe Nightfighters letting the Mossies
home in.

EW is such fun :)

Ed Rasimus

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
steve...@aol.com (SteveM8597) wrote:

> They were deployed to the 432nd in Mar 72
>during the Easter Offensive. They were apparently immediately successful with
>kills as soon as they arrived in theater, though I heard one was shot down
>shortly after its arrival. If I am not mistaken, one of the Wright Patterson
>AFB F-4D gate guards (554, don't recall the rest) was a tree bird. It has two
>kills to its credit.

The existence of "tree" was pretty close-hold at the time. I checked
out in the F-4 at Luke in Spring '72 and arrived at Korat in July '72.
No discussion of the equipment was provided and it wasn't until
December and LB II that I first heard mention of it.

More common knowledge was of the "agile eagle" modded E-models with
LES, TISEO, etc. All flown by the 555th TFS and usually operated (to
the frustration of the rest of the strike package) on a separate radio
frequency with dedicated GCI controllers.

> Not sure how much is stillclassified, but I will say that
>from an aircrew standpoint, it was a very effective and capable piece of gear,
>unlike some of the electronic systems in the F-4 (RHAW) to name one.

I can't agree with that statement totally. Certainly the APS-107 in
the D-models was incomprehensible to anyone but the engineer who
designed it, but the APR-36/37 was exceptional in my experience. It
certainly beeped and flashed too much, but with a bit of experience to
correlate presentation with actual events (seeing real missiles after
RHAW presentation), it was virtually perfect.

I recall taking my new Lt. WSO downtown for the first time in December
and interpreting the 36/37 noise for him. I reassured him that when we
got a real launch, the tone would be clear, the strobe would be bright
and the threat display would be very accurate. Ten minutes later, I
was proven right.

Ed Rasimus *** Peak Computing Magazine
Fighter Pilot (ret) *** (http://peak-computing.com)
*** Ziff-Davis Interactive
*** (http://www.zdnet.com)

Matt Clonfero

unread,
Jan 31, 1999, 3:00:00 AM1/31/99
to
In article <36b6b3b5...@news.btinternet.com>, Tex Bennett
<T...@btinternet.com> wrote:

>Sound similar to the "Serrate" kit fitted to NF Mosquitos that
>escorted the RAF Night Bombers later in WW2.
>It triggered the IFF sets Luftwaffe Nightfighters letting the Mossies
>home in.

Then again, the Luftwaffe had a bit of gear that homed in on the tail
radar of the heavies.

>EW is such fun :)

Lead and mislead.

Kurt Plummer

unread,
Feb 1, 1999, 3:00:00 AM2/1/99
to

Tex Bennett wrote:

> On Sun, 31 Jan 1999 18:03:35 +0000, Matt Clonfero
> <Ma...@aetherem.demon.co.uk> wrote:
>
> >In article <36B31D...@dial.pipex.com>, Jon W <xw...@dial.pipex.com>
> >wrote:
> >>Reportly a Vietnam era (c 1972) fighter bourne electronic long distance
> >>method of identification of friend or foe.
> >>
> >>Anyone any further info on what is was and how it worked?
> >
> >IIRC it polled the IFF units fitted to North Vietnamese Air Force
> >aircraft. Getting a positive Combat Tree reading was sufficient
> >identification to engage with Sparrow, instead of having to wait for a
> >visual ID.
>

> Sound similar to the "Serrate" kit fitted to NF Mosquitos that
> escorted the RAF Night Bombers later in WW2.
> It triggered the IFF sets Luftwaffe Nightfighters letting the Mossies
> home in.
>

> EW is such fun :)

Hey Tex,

Yeah it is, if you happen to be on the winning side...'Gotta git me wunnadem
Russki Radios' doesn't quite parleview from my perspective...;)

Serrate-I-IV: RHAWS
Perfectos: IFF Spoofer Woofer

Also, if you ever get a chance, read _Confound and Destroy, 100Grp Operations
in WWII_ or _Intruder_ The one provides tabular data and the other a first
person account which shows that a lot of at least /night/ ops didn't really
improve with the use of intruders whether radar or RHAWS or Radar/RHAWS/IFF
equipped. I think this was at least partially to do with the useage of
'random' patrols (low equipped numbers with limited overtake and short sensor
ranges). They supposedly had better success near specific fields but with
the Luftwaffe 'migrating' and the Flakwehr shooting at every third swallow
call...

I would invite anyone else to go a little bit further it's always neat to
hear accounts from the Wiz War and there were -so- many variables to failure
or even 'success' (P-61 called to accounts for shooting a Mossie: "Uhh Gee,
it /looked/ like a Ju-88!"...;-/) that things seldom repeat.


KP

Tex Bennett

unread,
Feb 1, 1999, 3:00:00 AM2/1/99
to
On Sun, 31 Jan 1999 23:44:52 +0000, Matt Clonfero
<Ma...@aetherem.demon.co.uk> wrote:

>In article <36b6b3b5...@news.btinternet.com>, Tex Bennett
><T...@btinternet.com> wrote:
>

>>Sound similar to the "Serrate" kit fitted to NF Mosquitos that
>>escorted the RAF Night Bombers later in WW2.
>>It triggered the IFF sets Luftwaffe Nightfighters letting the Mossies
>>home in.
>

>Then again, the Luftwaffe had a bit of gear that homed in on the tail
>radar of the heavies.

That was the "Monica" tail warner - I forget what the Luftwaffe
homing receiver was called. Anyone?

As Kurt pointed out I was talking about Perfectos and not Serrate -
thanks Kurt.

>>EW is such fun :)
>

>Lead and mislead.

The in house magazine at Wyton was called "The Deceiver" IIRC.

Tex Bennett

unread,
Feb 1, 1999, 3:00:00 AM2/1/99
to
On Mon, 01 Feb 1999 00:53:21 -0700, Kurt Plummer
<ch1...@earthlink.net> wrote:


>Hey Tex,
>
>Yeah it is, if you happen to be on the winning side...'Gotta git me wunnadem
>Russki Radios' doesn't quite parleview from my perspective...;)
>
>Serrate-I-IV: RHAWS
>Perfectos: IFF Spoofer Woofer

Thanks Kurt - and a D'Oh! for me there :)

Being a member of the AOC I should be shit hot on this stuff - I blame
alcohol.

>Also, if you ever get a chance, read _Confound and Destroy, 100Grp Operations
>in WWII_ or _Intruder_ The one provides tabular data and the other a first
>person account which shows that a lot of at least /night/ ops didn't really
>improve with the use of intruders whether radar or RHAWS or Radar/RHAWS/IFF
>equipped. I think this was at least partially to do with the useage of
>'random' patrols (low equipped numbers with limited overtake and short sensor
>ranges). They supposedly had better success near specific fields but with
>the Luftwaffe 'migrating' and the Flakwehr shooting at every third swallow
>call...

I've only read Alfred Price's "Instrument of Darkness" which I also
commend to the audience. I also have the superb "The Radar War" by
David Pritchard which makes a refreshing change as it deals with the
German side of things.

I'm interested in your comments above - are you saying that because
there was no co-ordination of intruder ops they weren't as effective
as they could have been? I wonder if some kind of AWACs in a Heavy
based on H2S say, could have helped co-ord the bomber/intruder force?
- just idle speculation on my part

Matt Clonfero

unread,
Feb 1, 1999, 3:00:00 AM2/1/99
to
In article <36b5e99d...@news.btinternet.com>, Tex Bennett
<T...@btinternet.com> wrote:

>>Then again, the Luftwaffe had a bit of gear that homed in on the tail
>>radar of the heavies.
>
>That was the "Monica" tail warner - I forget what the Luftwaffe
>homing receiver was called. Anyone?

You got me.

>>>EW is such fun :)
>>
>>Lead and mislead.
>
>The in house magazine at Wyton was called "The Deceiver" IIRC.

Never saw a copy. I guess that's what you get for being stuck out in 84
Blg.

Dweezil Dwarftosser

unread,
Feb 2, 1999, 3:00:00 AM2/2/99
to
On Mon, 01 Feb 1999 17:55:31 GMT, T...@btinternet.com (Tex Bennett)
wrote:

>That was the "Monica" tail warner - I forget what the Luftwaffe
>homing receiver was called. Anyone?

"Monica tail warner" ? Was that a Secret Service guy ?
<G>

- John T.

Jeff Noakes

unread,
Feb 2, 1999, 3:00:00 AM2/2/99
to
In article <36b5e99d...@news.btinternet.com>, T...@btinternet.com (Tex
Bennett) wrote:

> On Sun, 31 Jan 1999 23:44:52 +0000, Matt Clonfero
> <Ma...@aetherem.demon.co.uk> wrote:
>

> >In article <36b6b3b5...@news.btinternet.com>, Tex Bennett


> ><T...@btinternet.com> wrote:
> >
> >>Sound similar to the "Serrate" kit fitted to NF Mosquitos that
> >>escorted the RAF Night Bombers later in WW2.
> >>It triggered the IFF sets Luftwaffe Nightfighters letting the Mossies
> >>home in.
> >

> >Then again, the Luftwaffe had a bit of gear that homed in on the tail
> >radar of the heavies.
>

> That was the "Monica" tail warner - I forget what the Luftwaffe
> homing receiver was called. Anyone?

Flensburg - it could detect "Monica" emissions from up to 60 miles away.
Naxos was the equivalent equipment for homing in on H2S emissions, and
could make successful detections from up to 30 miles away.

Hope this helps.

--
Jeff Noakes
Remove the "*" to reply by e-mail.

Tex Bennett

unread,
Feb 2, 1999, 3:00:00 AM2/2/99
to
On Tue, 02 Feb 1999 06:12:11 GMT, wc...@usa.net (Dweezil Dwarftosser)
wrote:

>On Mon, 01 Feb 1999 17:55:31 GMT, T...@btinternet.com (Tex Bennett)
>wrote:
>

>>That was the "Monica" tail warner - I forget what the Luftwaffe
>>homing receiver was called. Anyone?
>

>"Monica tail warner" ? Was that a Secret Service guy ?

LOL - As soon as I posted this I suddenly saw the comdeic value of
what I wrote.
Monica Tail Warner.... No, let's not start another Clinton thread!!
:0)

Tex Bennett

unread,
Feb 2, 1999, 3:00:00 AM2/2/99
to
On 2 Feb 1999 14:23:33 GMT, j*noa...@chat.carleton.ca (Jeff Noakes)
wrote:


>Flensburg - it could detect "Monica" emissions from up to 60 miles away.
>Naxos was the equivalent equipment for homing in on H2S emissions, and
>could make successful detections from up to 30 miles away.
>
>Hope this helps.

Yes - Thanks! Was Naxos also deployed on U-Boats to detect ASV
transmissions?

Jeff Noakes

unread,
Feb 3, 1999, 3:00:00 AM2/3/99
to
In article <36ba48a7...@news.btinternet.com>, T...@btinternet.com (Tex
Bennett) wrote:

Yes. It was a replacement/supplement for the "Hagenuk" (Wanze G.1) radar
detector. Wanze was an improved version of the Metox detector, and was
designed for reduced emissions - the Germans were under the mistaken
belief, courtesy of a captured pilot's deception, that Allied aircraft
were no longer using ASV but were homing in on the emissions from the
Metox radar detectors used by U-boats. This wasn't the case, but Metox
was tested and was found to emit radiation that could conceivably be
detected, so an improved version with reduced emissions, Wanze, was
produced. Wanze covered the 120 to 180 centimetre wave band, and so
couldn't detect the 10 cm ASV that many Allied ASW aircraft were using.
Efforts to further reduce the emissions from the Wanze G.1 detector led to
the development of a new model, Wanze G.2, codenamed "Borkum", which
reached the production stage by the last week of October 1943. Borkum
covered the 75 to 300 cm range, but could detect strong emissions in the
10 cm band.

In the meantime (and this is where Naxos comes in), according to "The RAF
in Maritime War,"

"early in September Doenitz had happened to be in a conversation with a
leading German physicist (Professor Esau) who was aware of the use by
R.A.F. Bomber Command of centimetric equipment (H2S) and of the measures
adopted by the G.A.F. to counter it. No positive action was taken by
Doenitz until nearly the end of September when his attention was focussed
on the efforts made by a batch of U-boats to penetrate past Gibraltar into
the Mediterranean. All three of the first comers reported continuous
surprise night locations and attacks of which no warning was given by
their Hagenuk wave indicators. Although one succeeded in getting through,
the others were beaten back and Doenitz abandoned further attempts. He
noted in his War Diary that it was suspected that the aircraft were using
centimetric A.S.V. Accordingly he sent for Professor Esau and
arrangements were expedited to modify the G.A.F. indicator - code name
Naxos - (*) for fitment into U-boats. No further attempt to enter the
Mediterranean was to be made until the boats had been so equipped."

(*) "The ex-G.A.F. Naxos set was a detector receiver for the 8 to 12 cm.
band. The maximum theoretical range on our Mk.III 10 cm. A.S.V. was no
more than about five miles. It was a delicate instrument with a long coil
of flexible cable and had to be passed below from the bridge before
diving. It was also adversely affected by spray and in general was a
makeshift affair."(1)

U-boats fitted with Naxos continued to suffer heavy losses from air
attack, which discredited the receiver and the theory that the Allies were
using 10 cm ASV, and confirmed incorrect German suspicions that the Allies
were homing in on electromagnetic radiation from equipment on board
U-boats. Naxos continued to be fitted to U-boats, though, not because it
covered the 8 to 12 cm wave band but because it didn't radiate.

This situation didn't change until the end of 1943 when Dönitz became
dissatisfied with the proliferation of research, and ordered that it be
re-organized. He created a Naval Scientific Directional Staff to
co-ordinate radio and radar matters, under the guidance of a Professor
Kuepfmuller, who was directly subordinate to Dönitz. This committee
established that the Allies were using 10 and 3 cm ASV, and made Naxos the
standard detector until a more effective replacement could be provided.(2)

Naxos was replaced by the Fliege and Mücke detectors, which were used to
detect 10 and 3 cm radar emissions respectively. They were combined in
May 1944 to produce a detector called Tunis.

Hope this helps.

Sources:

(1) Great Britain. Air Ministry. Air Historical Branch, _The R.A.F. in
Maritime War, Volume IV: The Atlantic and Home Waters - The Offensive
Phase, February 1943 to May 1944_, 174.

(2) _ibid_, 175.

Reply all
Reply to author
Forward
0 new messages