The SIGINT community is notoriously loath to completely declassify it's historical materials, even documents over a half-century old. But thanks to an FOIA request submitted in 2015 by Dr. Christine Lamberson of the Angelo State University History Department, we have now received copies of almost all the 6994th Security Squadron histories, including those of the detachments. Beginning in January, 1966, these classified, limited distribution histories were compiled and published twice yearly, representing the periods 1 January-30 June and 1 July-31 December.
The format of the histories, which varied somewhat over the years, appears to have been dictated by USAFSS Headquarters in San Antonio. The first chapter was generally titled “Mission and Organization”, followed by “Tasking and Collection”, then one or two more chapters dealing with “Processing and Reporting” and occasionally one-time topics such as “Special Projects” or “Hostile Activities.” For the years 1966 through 1968, the detachment histories are embedded within the main 6994th histories, along with the histories for the ARDF Coordination Center (ACC) when those histories were included.
The quantity and quality of operational details—that is, mission objectives and results—vary greatly. For instance, the early histories contain a fair amount of data relating to supported ground operations which, when viewed side-by-side with contemporary After Action Reports and “official” war histories written years later, make it possible to “connect the dots” and understand the impact our EC-47 crews and their support functions made on the conduct of the war. Some histories contain fewer operational details but shed light on the technical, tactical, and political considerations which influenced EC-47 operations.
The supporting documents appended to most of the histories represent the documentary foundation around which the histories were written. Unfortunately, much of this material remains redacted due, apparently, to the various intelligence "equities" involved, each of which must separately agree to release "their" material—a process that would add years to the already interminable delays encountered in receiving answers to an FOIA request. Regardless, these unit histories probably represent the nearest thing to an ongoing account of the SIGINT aspects of EC-47 operations—written more or less as the events occurred—that still exists.
By the fall of 1971 the drawdown of U.S. forces in Vietnam was well underway. The 460th Tac Recon Wing stood down on 31 August; the TEWS were subordinated to the 483d Tactical Airlift Wing, presumably to consolidate units flying prop-driven aircraft. When the 483d in turn went away, the remaining EC-47 squadrons were assigned to separate 7th Air Force wings. Det 1 of the 6994th (Phu Cat) was inactivated on 31 October, its personnel absorbed by Det 2 at Da Nang. Det 3 continued to operate out of NKP.
The histories from 1966 through 1971 are linked below. Histories not received are so indicated. Whether these were never written, have been lost, or simply not yet declassified, we don't know. The post-1968 histories are larger files. As a matter of convenience and to shorten download times the detachment histories have been extracted and processed as separate files. (Beginning with 1970, Det histories were received separately.) To reduce file size, some supporting documents have been extracted as well.
NOTE: These files may be viewed in your web browser. However, the histories have been booked-marked for easy access to the various sections. For optimum viewing, right-click on the link then "Save link as ... " to a location on your hard drive.
At the end of November, 1972, operations at Tan Son Nhut ceased. The 6994th moved to NKP, while Det 2 hung on at Da Nang until the end of February when it was inactivated. By that time, all USAF EC-47 operations had moved to NKP. Listed are the histories for that timeframe:
6994th History, January-June, 1972
6994th History, July-December, 1972 (Not Received. Unit moved to NKP 1 Dec 1972)
Det 2 History, January-June, 1972 *
Det 2 History, July-December, 1972 (Inactivated 28 Feb 1973)
Det 3 History, January-June, 1972
Det 3 History, July-December, 1972 (Not Received)
6994th History, January-June, 1973
6994th History, July-December, 1973 (Not Received)
6994th/Det 3 History, July 1973-January 1974
? ? ? January-May, 1974 ? ? ?
In January, 1974, operations moved from NKP to Ubon Royal Thai AFB. The last USAF EC-47 missions flew from Ubon on 15 May 1974. In 1971, the South Vietnamese began training to take over 33 Electric Goons and by late 1972 the lone VNAF EC-47 squadron was operational. When Saigon fell on 30 April 1975, those EC-47s still flyable took off for Thailand, just ahead of onrushing NVA troops.
If you can elaborate on some aspect of these histories, or if you have a comment or question, by all means let us know!