Vietnam era F-4s Q

Hello

many thanks to everybody who came it this topic and have answered all my questions.
Great discussion

Best wishes
Ivan

"Guy Alcala" wrote in message
. ..
Zajcevi wrote:
..
Was APX-76 used on F-4Js/Es, and also Combat Tree birds?

No idea. The diagrams of F-4E cockpits I've got show the IFF interrogator
panel (in the RCP, left of the radar scope) as a
blank panel, but photos show that it is indeed for that purpose.
Unfortunately, the label can't be seen. Photos of the
back cockpit of F-4Gs show a panel labeled APX-80 in the same spot.

I can't answer when APX-76 was first put in Phantoms, nor whether Combat
Tree birds also had APX-76, but I worked on APX-76 in F-4Es in the early
1980s, along with APX-81. I believe APX-81 may have been "Combat Tree",
though it is also quite possible Combat Tree was an earlier generation
Soviet IFF Interrogator than APX-81. The "APX-80" control box at the WSO's
lower left panel by his left knee controlled both the APX-76 and APX-81. To
my knowledge there was never really any such thing as "APX-80" other than
what was printed on the control box. I always figured 80 was sort of an
average between 76 and 81, so that's why it was labeled as such on the
control box. APX -76 was a real piece of **** so far as reliability. As a
Comm-Nav avionics specialist, I spent more time working on APX-76 writeups
than all the other systems I worked on combined. The aircrews seemed really
love it when it worked, it helped them find targets much more easily than
just trying to get a radar paints.
Scott Wilson

I can't answer when APX-76 was first put in Phantoms, nor whether Combat
Tree birds also had APX-76, but I worked on APX-76 in F-4Es in the early
1980s, along with APX-81. I believe APX-81 may have been "Combat Tree",
though it is also quite possible Combat Tree was an earlier generation
Soviet IFF Interrogator than APX-81. The "APX-80" control box at the WSO's
lower left panel by his left knee controlled both the APX-76 and APX-81. To
my knowledge there was never really any such thing as "APX-80" other than
what was printed on the control box. I always figured 80 was sort of an
average between 76 and 81, so that's why it was labeled as such on the
control box. APX -76 was a real piece of **** so far as reliability. As a
Comm-Nav avionics specialist, I spent more time working on APX-76 writeups
than all the other systems I worked on combined. The aircrews seemed really
love it when it worked, it helped them find targets much more easily than
just trying to get a radar paints.
Scott Wilson



I think that one of the earliest applications must have been the Misawa F-4Da
that belonged to the 475th TFW in 1971 or so and then transferred in 1972 to
the 3rd TFW at Kunsan. Combat Tree was indeed useful for such things as tanker
rendezvous weather joinups, and yes we used it to pick out hostile tracks at a
distance. It would locate a tanker at 150 miles whereas the radar would not
see one until less than 50 miles.

The 8 or so birds that were so equipped were sent to Thailand during the April
72 NVN offensive. One was immediately shot down after it arrived but the
others had some success. One of them with two MiG kills guards the main gate
at Wright-Patterson AFB today. Tail# is 550 but I forget the block number.
Probably 63-XXX

Smartace11 wrote:

I can't answer when APX-76 was first put in Phantoms, nor whether Combat
Tree birds also had APX-76, but I worked on APX-76 in F-4Es in the early
1980s, along with APX-81. I believe APX-81 may have been "Combat Tree",
though it is also quite possible Combat Tree was an earlier generation
Soviet IFF Interrogator than APX-81. The "APX-80" control box at the WSO's
lower left panel by his left knee controlled both the APX-76 and APX-81. To
my knowledge there was never really any such thing as "APX-80" other than
what was printed on the control box. I always figured 80 was sort of an
average between 76 and 81, so that's why it was labeled as such on the
control box. APX -76 was a real piece of **** so far as reliability. As a
Comm-Nav avionics specialist, I spent more time working on APX-76 writeups
than all the other systems I worked on combined. The aircrews seemed really
love it when it worked, it helped them find targets much more easily than
just trying to get a radar paints.
Scott Wilson



I think that one of the earliest applications must have been the Misawa F-4Da
that belonged to the 475th TFW in 1971 or so and then transferred in 1972 to
the 3rd TFW at Kunsan. Combat Tree was indeed useful for such things as tanker
rendezvous weather joinups, and yes we used it to pick out hostile tracks at a
distance. It would locate a tanker at 150 miles whereas the radar would not
see one until less than 50 miles.

I presume you meant APX-76 for tanker join-ups? Combat Tree wouldn't seem to be
useful for them, unless our KC-135s were carrying Soviet IFF systems ;-)


The 8 or so birds that were so equipped were sent to Thailand during the April
72 NVN offensive. One was immediately shot down after it arrived but the
others had some success. One of them with two MiG kills guards the main gate
at Wright-Patterson AFB today. Tail# is 550 but I forget the block number.
Probably 63-XXX

A FY-63 bird would be a C-model, and the full number would be 63-7550. The dual
MiG-kill C-model IN the museum is 64-0829, in which Robin Olds claimed two MiG-17s
on 20 May 1967:

http://www.wpafb.af.mil/museum/modern_flight/mf47.jpg

here's another shot of the same a/c outside:

http://www.wpafb.af.mil/museum/modern_flight/mf47.htm

66-7550 was the F-4D in which Dan Cherry/Jeff Feinstein got a MiG kill on 18 April
1972, but at least at that time it wasn't equipped with Combat Tree (per Red Baron,
which says that only Lead was Tree-equipped in that fight. Lead was Fred Olmsted
in Basco 01; Cherry was Basco 03). "and Kill Migs" says the tail code of Cherry's
a/c was 'PN', which would mean that the a/c was from the 405th at Clark.

Thornborough (via Alan Howarth) lists the first 8 Combat Tree birds as Block 29
D-models FY 65-0783 through -0785 and -0801, and FY 66-0232, -0237, -7463 and
-7482. He states that three of the 8 had been lost by June '72, and replacements
were sent between June and September. The total number sent is unknown, but
included 66-0239/-0240, -0267 through -0269, -0271, -7459, -7461, -7468, -7486 and
-7501.

Guy

"Scott R. Wilson" wrote:

"Guy Alcala" wrote in message
. ..
Zajcevi wrote:
.
Was APX-76 used on F-4Js/Es, and also Combat Tree birds?

No idea. The diagrams of F-4E cockpits I've got show the IFF interrogator
panel (in the RCP, left of the radar scope) as a
blank panel, but photos show that it is indeed for that purpose.
Unfortunately, the label can't be seen. Photos of the
back cockpit of F-4Gs show a panel labeled APX-80 in the same spot.

I can't answer when APX-76 was first put in Phantoms, nor whether Combat
Tree birds also had APX-76, but I worked on APX-76 in F-4Es in the early
1980s, along with APX-81. I believe APX-81 may have been "Combat Tree",
though it is also quite possible Combat Tree was an earlier generation
Soviet IFF Interrogator than APX-81. The "APX-80" control box at the WSO's
lower left panel by his left knee controlled both the APX-76 and APX-81. To
my knowledge there was never really any such thing as "APX-80" other than
what was printed on the control box. I always figured 80 was sort of an
average between 76 and 81, so that's why it was labeled as such on the
control box.

snip

Thanks for the info, that clears up a lot of confusion about APX-80/-81.

Guy

(Smartace11) wrote:


I presume you meant APX-76 for tanker join-ups? Combat Tree wouldn't seem to
be
useful for them, unless our KC-135s were carrying Soviet IFF systems

At that time the whole system was called Combat Tree, as least by the aircrews.
I was a dumb crew dog and just flew the things


I'll go with Guy on this one. The beacon mode of the E-model radar we
were using at Korat sure wasn't Tree. It worked on 100 and 200 mile
scope and was nice for finding your tanker. But it was strictly
"cooperative" target recognition.

I used to tweak Rod Bates, my back-seater after Linebacker II, to take
tanker "judy" as far out as he could. If he could get the tank to
squawk, he'd try to judy in the turn out of traffic. He got some
contacts at 125 to 150 miles and ran the whole intercept.

Of course, the beacon return on that long a range was a wide slash on
the scope. It got you going in the right general direction and you got
a refined return as you closed the range. By the time you got to skin
point you would be right on track.

Sorry bout this one, Steve, you're old memory is fading. CRS, I guess.



Ed Rasimus
Fighter Pilot (ret)
***"When Thunder Rolled:
*** An F-105 Pilot Over N. Vietnam"
*** from Smithsonian Books
ISBN: 1588341038

Smartace11 wrote:

snip

66-7550 was the F-4D in which Dan Cherry/Jeff Feinstein got a MiG kill on 18
April
1972, but at least at that time it wasn't equipped with Combat Tree (per Red
Baron,
which says that only Lead was Tree-equipped in that fight. Lead was Fred
Olmsted

Again just a dumb crew doig here. My log indicate that bird had it installed
at the Kun'.

Could be. There's a photo of Cherry with a big SEG in "And Kill MiGs," standing on
the a/c ladder of an F-4 with both a red star and the Combat Tree self-destruct
package placard on the splitter plate ("WARNING DESTRUCT SAFETY PIN MUST BE
INSTALLED PRIOR TO EJECTION SEAT MAINTENANCE T.O. 1F-4D-2-3CL-1"), but there's no
way to tell what the tail number is. It could be a different a/c - the red star
doesn't appear to be brand new, but looks slightly weathered. Olmsted had gotten a
kill on 30 March, and 555th crews Lodge/Locher and Kittinger/Hodgdon had both
claimed MiGs at night while flying Lead in Combat Tree a/c, on 21 Feb and 1 March
respectively. Here's all the Red Baron III summary says:

"Event 11. 16 April 1972/1035H. Fargo: Four F-4Ds, Lead equipped with Combat
Tree, providing MiGCAP support for the first daylight strike in RP-6 in over 4
years, encountered four MiG-21s and destroyed two."

Cherry's (presumably unclassified) account in "And Kill MiGs" says that Olmsted's
WSO Stu Moss got contact at 20nm and was apparently the only a/c to get contact as
the range closed to 5nm, at which point "we picked them up visually," so it may
well have been a skin paint. In addition to Olmsted, Cherry states that the other
two ACs in 02 and 04 were Steve Cuthbert and Greg Crane.

FWIW, some years back I checked Alan Howarth's F-4D Combat Tree-equipped serial
number list against F-4D kill claims where either Red Baron or occasionally other
sources stated/indicated that the a/c had Combat Tree installed, and AFAIR all
matched up. Doesn't mean that an a/c or two might not have slipped through his
list, or that Red Baron is error-free. OTOH, there were supposedly only 8 Tree a/c
total in the 555th and 13th TFS' at the time, and Cherry says that the 432nd put up
five MiGCAP flights for the mission; given the usual non-operational a/c, typically
only the lead a/c in each flight would be TREE-equipped. If they had an extra then
the element lead would get the other Tree bird, and since Cherry was flying 03 it's
not impossible that he had one.

I guess you could ask Jeff, a squadron mate at the time in the
80th.

Be happy to; could you give me an intro and/or his email, or ask him for me?

Guy

I'll go with Guy on this one. The beacon mode of the E-model radar we
were using at Korat sure wasn't Tree. It worked on 100 and 200 mile
scope and was nice for finding your tanker. But it was strictly
"cooperative" target recognition.

I never got any more than 100 mile skin paints on tankers in the F-4D radar and
that was rare, but you are right, the beacon mode would pick it up
a long ways out when it worked. I guess the tanks used it routinely on the
BUFF joinups. I usually let GCI do the vectoring until about 50 - 75 nm then
take when I got a skin paint, judy at 50-60 nm and turn the tanker at 35 nm.

Loved the 5 nm range indicator in the E - great for joinups in the weather at
nght.

Be happy to; could you give me an intro and/or his email, or ask him for me?

I lost contact with him years back and have no idea where he is but I will look
him up in my 80th Headhunters roster - think I saw his name there. He and I
were in F-4 RTU, the 391st at Misawa and 80th at Kunsan together then he went
to Udorn and I went to Tahkli via Holloman.

At the time of its MiG Kill 66-7550 was sporting the red fin flash and
PN tail code of the 523d TFS from Clark. Did you guys give some of
your jets to them as well as the 555th and 13th TFSs?

Just curious...

I had left the Kun' a month before the planes were transferred (Apr 72) and got
to Holloman just in time to repack my bags for Tahkli. I was under the
impression that all of then went to the 555th but that is just an assumption.
The Combat Sage guys at
Clark could have had their hands on one for testing.
Juvat (...F-16A era)