Thursday, March 13, 2014

US Navy F-4 EW development - Revisited

Ok, let’s try this again.  After much research and a heap of help from Mike France and Craig Kaston, I think I can present a better picture of the sequence of EW fits to the Navy Aircraft.   I will be presenting these in several parts, so keep coming back to see what has been posted. If you are new to this subject or these posts, I suggest you start by reading the first section so you get some background. 

Just click on the links to read more about each system.


BACKGROUND INFORMATION


  • Historical Background

1965 / 1966


Equipment installed without Airframe Change (AFC):
F-4B
AFC-331 Pt. 1 (ECP-F-4-703 &703S1) installs:
F-4B, F-4J*
The KY-28 was installed on all aircraft, ships, and fixed bases in the Vietnam theater of operations starting in 1965. It synced with the KY-38 man pack used by ground forces and KY-8 vehicular unit. These units provided secure encrypted voice communications.
* F-4Js would come off the assembly line with this equipment installed.

1966 / 1967


Equipment installed without Airframe Change (AFC):
F-4B
Installed on all F-4B aircraft for VF-92 and VF-96 on CVAN-65 USS Enterprise during its 1966-1967 Vietnam cruise. These were the only aircraft with this equipment.
F-4B
Installed on 4-5 aircraft for VF-151 and VF-161 on CVA-64 USS Constellation, 4-5 aircraft for VF-14 and VF-32 on CVA-42 USS Franklin D Roosevelt, and 4-5 aircraft for VF-96 on CVAN-65 USS Enterprise during their 1966-1967 Vietnam cruises. This equipment was removed after their cruise.
AFC-296 (ECP-F-4-707R1) installs:
F-4B
Sent as kits and installed on-board during the 1966-1967 Vietnam Cruises of CVA-64 USS Constellation, CVA-42 USS Franklin D Roosevelt, and CVAN-65 USS Enterprise. Future deployments had the APR-27 installed prior to departure.

1967 / 1968


This is a time when the changes made to the EW equipment gets sort of messy. There were a lot of new EW developments that were happening in quick succession. With these changes happening so quickly it isn't always easy to tell how an aircraft was configured by merely looking at fairings. This is because we often see that a change was made and the old fairings weren’t removed, just left empty (or full but disconnected) or that old fairings were used with new equipment installed. 
Equipment installed without Airframe Change (AFC):
F-4B

(This will be referred to as "AN/APR-25 Mod 1" for our purposes - click here for more information.)

This was a pre-Shoehorn fit as seen only in aircraft of VF-142 and VF-143 on CVA-64 USS Constellation during its 1967 Vietnam cruise.
PROJECT SHOEHORN
Project Shoehorn was a program providing a complete suite of EW equipment to the F-4Bs. It was considered "state of the art" at the time, and several doors had to be added/enlarged to provide room to "shoehorn" in all the needed equipment.



AFC-333 (ECP-F-4-707R1S1, S2) installs:
  • Melpar Inc. AN/APR-30 S/C/X-band Radar Homing & Warning System
F-4B
F-4B
F-4B
AFC-334 (ECP-F-4-761S1) installs:
F-4B
  • Magnavox AN/ALQ-91 IFF Countermeasures System
F-4B
F-4B
First seen on CVA-59 USS Forrestal with VF-11 and VF-74 on its tragic 1967 Vietnam cruise. It should be noted that the Forrestal's squadrons showed a mix and match of aircraft on this cruise. Some were fully configured with the new shoehorn fit while others were not. It has been suggested that delays in the equipment becoming fully operational meant that the Forrestal had to sail before all her F-4Bs were fully modified to the "Shoehorn Mod 1" spec. I would imagine that the unmodified aircraft would be paired with a Shoehorn aircraft to offer some type of protection.

The disastrous fire on ship soon after the start of combat operations ended any mid cruise updates and so her surviving F-4B aircraft were not finally brought up to the full spec until her return to the USA in September 1967 with all being updated by early 1968. These surviving aircraft would appear to be the same as those modified under AFC-339 and AFC-375 in 1967 having the original APR-30 fairings but being equipped with APR-25 under the skin.

CVA-43 USS Coral Sea with VF-151 and VF-161 during her 1967-1968 Vietnam cruise ws the only carrier to bring a full compliment of  "Shoehorn Mod 1" equipped F-Bs into the Vietnam conflict. The USS Coral Sea along with the USS Forrestal were the only carriers to deploy the "Shoehorn Mod 1" equipped F-4Bs into Vietnam.

AFC-339 (ECP-F-4-761) and AFC-375 Pt.1 (ECP-F-4-830) installs:
F-4B
  • Magnavox AN/ALQ-91 IFF Countermeasures System
F-4B
AFC-375 Pt.1 (ECP-F-4-830) and AFC-375 Pt.2 (ECP-F-4-707R2) installs:
  • Applied Technology Inc. AN/APR-25 S/C/X-band Radar Homing & Warning System
F-4B
F-4B
F-B
It would seem that the Navy was not happy with APR-30 and decided to replace it with the proven APR-25 RHAW system and did so with many aircraft already on the mod line being prepped for APR-30 Shoehorn Mod 1.

Appears on F-4Bs of VF-21 and VF-154 on the CVA-61 USS Ranger, VF-11 and VF-213 on the CVA-63 USS Kitty Hawk, and VF-92 and VF-96 on CVAN-65 USS Enterprise on their 1967-1968 Vietnam cruises.

1968 / 1969








AFC-339 (ECP-F-4-761) and AFC-375 Pt.1 (ECP-F-4-830) continues to install:
F-4B
  • Magnavox AN/ALQ-91 IFF Countermeasures System
F-4B
AFC-375 Pt.1 (ECP-F-4-830) and AFC-375 Pt.2 (ECP-F-4-707R2) continues to install:
  • Applied Technology Inc. AN/APR-25 S/C/X-band Radar Homing & Warning System
F-4B
F-4B
F-B


The first aircraft to be modified to "Shoehorn Mod 3" specs in 1968 were those on the USS Constellation with VF-142 and VF-143. They differed from what became the standard 1968 fit in that while they did indeed have a single fairing fin cap already in place from their 1967 cruise they also were fitted with the original APR-30 hook shaped chin pod fairing. It is thought this was nothing more than using up the last of the available stocks of these fittings and indeed a small number of the first Marine aircraft to go into the Shoehorn project acquired the same fit.

New aircraft coming into VF-151 and VF-161 on the Coral Sea were the first to get the new and correct shaped antenna fairings associated with AFC-339 and AFC-375. It should be noted that the aircraft assigned in 1967 that were to stay with the Coral Sea's squadrons retained their original APR-30 fairings but had the revised fairings fitted when they returned Stateside at the end of the 1967 / 1968 Vietnam cruise. 

1968 saw the introduction of the F-4J to Vietnam combat operations deploying with VF-33 and VF-102 on CVA-66 USS America. The aircraft assigned to these squadrons were the first Navy F-4Js to get the shoehorn mods on the production line and the first of them was BuNo. 155529.


AFC-352 (ECP-F-4-687S3) installs:
  • Hazeltine AN/APX-76 Air-to-Air IFF System
F-4B
AFC-388 (ECP-F-4- 840S1, S2) installs:
  • Applied Technology Inc. AN/APR-25 S/C/X-band Radar Homing & Warning System
F-4J
F-4J
F-4J
  • Magnavox AN/ALQ-91 IFF Countermeasures System
F-4J
  • Hazeltine AN/APX-76 Air-to-Air IFF System
F-4J


The USS America was followed in to combat operations by (Shoehorn Mod 3) modified F-4B aircraft of VF-151 and VF-161 on CVA-43 USS Coral Sea,
VF-21 and VF-154 on CVA-61 USS Ranger with (Shoehorn Mod 4) F-4J aircraft,
VF-11 and VF-213 on CVA-63 USS Kitty Hawk with
(Shoehorn Mod 3)  F-4Bs and VF-92 and VF-96 on CVAN-65 USS Enterprise with (Shoehorn Mod 3) F-4Bs.

F-4B aircraft from this 1968 / 1969 deployment period world wide would show a mix of aircraft with the original AN/APR-30 fittings of Shoehorn 1&2 and the later AN/APR-25 fittings of Shoehorn 3. But it is worth noting all aircraft would have the same AN/APR-25 RHAW system under their different skins.

It should be noted that USMC aircraft in the Pacific area finally got their own aircraft straight from the new mod lines set up in Japan and in the Philippines during this 1968 /1969 time frame. Previously any shoehorn aircraft seen with the Marines would have been ex US Navy aircraft swapped out when the Navy deployments were done. There would always be a lot of aircraft switching between Navy and Marine squadrons in this period.

During this period Atlantic fleet carriers would also start to get AN/APR-25 Shoehorn equipped F-4s (CVA-59 USS Forrestal being the only Atlantic carrier to have AN/APR-25 equipped aircraft prior to this time).

1970


APC-524 (ECP-F-4-1023R2S1, S2) installs:
  • Applied Technology Div. (ITEK) AN/ALR-45 Countermeasures Receiving Set
F-4B, F-4J
  • Raytheon AN/ALR-50 Radar Receiving Set
F-4B, F-4J

1975


AFC-541 (ECP-F-4-1035S1) installs:
F-4J*, F-4N**
*The first F-4Js did not have this system installed during assembly, but looking at my resources I begin to see a few with the modification appearing by late 1972. But there are also many pictures without the modification in this time frame so the conversion is by no means complete.  Pictures from 1975-76 show that most aircraft had been converted by this time.

** The first F-4Ns did not have this system installed initially during conversion, but were retrofitted by 1975. The first carrier deployment of F-4Ns was on CVA- USS Midway out of Yokosuka, Japan from September to October 1973. These aircraft did not have the shoulder wave guide antennas of AN/ALQ-126 fit yet.

Revision History:
  • 29 MAR 2014 - Added pages for Shoehorn Mod 4
  • 24 MAR 2014 - Added pages for AN/APR-25, AN/ALQ-51/100 & AN/ALQ-126
  • 19 MAR 2014 - Added pages for Shoehorn Mod 1, 2, & 3
  • 13 MAR 2014 - Original Post
Sources:
  • Michael France and his unending patience and tremendous work on F-4 Phantom II changes
  • Craig Kaston and his patience and help with the "Navy Way" of doing things