Term or Acronym Description
7th Air Force The 7th Air Force, a numbered air force (also "7 AF" ... see history fact sheet) was activated on 28 March 1966 to take over the mission, functions, and activities in Vietnam of what was at the time the 2d Air Division (a smaller, now obsolete, type of organization). Located at Tan Son Nhut Air Base (near Saigon) the 7 AF was the Air Component Command of the Military Assistance Command (MACV) and responsible for most USAF operations in Vietnam from April 1966 through 1973. (Trivia: In late 1965 or early 1966, General Joseph Moore, then commander of 7th AF, tried to put control of the ACRPs under the 7 AF, but NSA, with good reason, nixed that idea.)
25th Air Force
(25 AF)
Current successor organization (sixth iteration) to USAFSS. Redesignated 25 AF on 29 September 2014 to succeed AFISRA.
See “Successor Organizations". (See also the 25 AF Fact Sheet.)
ACRP Airborne Communications Reconnaissance Program. After the term was coined, "ACRP" often simply referred to the "Airborne Communications Reconnaissance Platform" — i.e., the actual aircraft, e.g., RB-50, RC-130 or RC-135 — depending on context.
AFB Air Force Base (mostly used after name of AFB, e.g., Offutt AFB). Overseas most USAF military installations are "Air Bases" (AB, e.g., Yokota AB).
AFCYBER Air Force Cyber Command (24th Air Force)
AFEWC Air Force Electronic Warfare Center
AFIC Air Force Intelligence Command. The third iteration of USAFSS (1991-1993).
AFISRA Air Force Intelligence, Surveillance, and Reconnaissance Agency (2007-2014). The fifth of six successor organizations to USAFSS. (See also the AFISRA Fact Sheet)
AFOUA Air Force Outstanding Unit Award. The 6988th SS was awarded a total of five AFOUAs during its existence.
AFSA Armed Forces Security Agency (1949-1952) a failed organization that was the precursor to NSA.
AFSC Air Force Specialty Code: An alphanumeric code used to specify a given specialty (career field) and proficiency level. The AFSCs for USAFSS were entirely different than what is used today. Previously, a linguist would have a five-digit AFSC beginning with "203" and a suffix to denote language in his current assignment (some linguists cross-trained and learned a 2nd or 3rd language). The suffixes most commonly seen in the 6988th were "-1" for Russian, "-2" for Chinese, "-4" for Vietnamese and "-9" for Korean. the dash and number were replace in the mid-sixties with "MA" for Russian, "MB" for Chinese, etc. AFSC is the AF version of "MOS" (Military Occupational Specialty) that's used by the Army and Marine Corps.
AFSS (USAFSS) Air Force Security Service. Created in 1948, USAFSS was tasked with a cryptologic mission and to provide communications security (COMSEC) for the relatively new Department of the Air Force. USAFSS was the Air Force Cryptologic and SIGINT operating agency (collection arm) of the NSA. (See Service Cryptologic Component)
AIA Air Intelligence Agency. The fourth of six successor organizations to USAFSS (1993-2007)
aka "also known as" ...
AMS Airborne Mission Supervisor - At the 6988th, this person was our "Bat 1" ... the guy in charge.
AMT Airborne Maintenance Technician ... the behind-the-scenes and much-appreciated guys who expertly kept everything working
AO Agent Orange
ARP Airborne Reconnaissance Program
ARVN Army, Republic of Vietnam
ASA Army Security Agency - 1945-76. Its successor (1977) is INSCOM, US Army Intelligence and Security Command
Back-ender Typically a "back-ender" refers to an airborne SIGINT reconnaissance crewmember of any specialty — e.g., linguist [voice intercept operator], Morse intercept operator, analyst, ELINT intercept honcho, AMS or AMT. Compare front-ender.
Bat A back-ender (see above) in, and arguably unique to, the 6988th SS (or one of its Dets) (~1954?-1972). Note the round, gray & black "Bat patch" at the top of each page on this site. Most Bats wore this patch on their flight suit.
C2 Command and Control (sometimes C2)
C3 Command, Control and Communications (sometimes C3)
C4 Command, Control, Communications & Countermeasures (sometimes "C3CM" or C4)
C4I Command, Control, Communications, Computer and Information (sometimes C4I)
CIA Central Intelligence Agency
Combat Apple The unclassified project name used to identify the RC-135's that were assigned to the 6091st SRS/556th RS at Kadena AB, Okinawa, and crewed by USAFSS back-enders [mostly] from the 6990th SS.
COMINT Communications Intelligence. Information obtained for intelligence purposes from the intercept of foreign language communications by other than the intended recipient(s).
Commando Lance One of three project names used for RC-130B-II ACRP missions in SE Asia during the Vietnam War. The three were "Queen Bee," Charlie and Delta (fall 1963 - fall of '65), "Silver Dawn" (fall '65 - Feb '67), and "Commando Lance" (Feb '67 - 31 Dec '67).
COMSEC Communications Security. The protection of US Government radiotelephone and other telecommunications from exploitation by unintended recipients. This includes ensuring the security of cryptosystems, preventing electronic emissions from, and physically protecting, communications equipment. COMSEC dates back to WWI.
Cryptologic Linguist A Cryptologic Linguist monitors, records, complies, processes and examines signals intelligence (SIGINT) information, using radio receivers, recording devices, and related equipment.
CSS The Central Security Service (CSS) was created in 1972 as a companion organization to NSA "to promote full partnership between the NSA and the service cryptologic components (SCCs) of the Armed Forces." CSS conducts SIGINT collection, processing, analysis, production, and dissemination, and other cryptologic operations as assigned by DIRNSA — the Director NSA / Chief CSS (one individual).
CW Continuous Wave (or waveform). In common usage, "CW" refers to (and is essentially synonymous with) Morse Code.
DAV Disabled American Veterans
Det Detachment. In the Air Force, detachments are segments or parts of a larger unit, generally located away from the physical location of the parent unit. Detachments usually carry a number, such as Detachment 5 (often abbreviated: "Det 5", "Det 2", etc.), of a particular squadron. Any unit may have one or more detachments, which are often mistaken for units because they have commanders and are subject to some of the same organizational actions applying to units, including activation, assignments, and inactivation.
DF Direction-finding. Fundamentally, direction-finding detects azimuth (direction, usu. in degrees from north; not distance or altitude, if airborne) of the origin of a radio transmission; typically in the VHF or UHF frequency bands because those frequencies are unidirectional as opposed to omni-directional. "Triangulation" must be employed to determine estimated location.
DIA Defense Intelligence Agency (US Department of Defense)
DIRNSA Director, National Security Agency. Also serves as Chief, Central Security Service. Acronym is typically used as DIRNSA/CHCSS.
DLI Defense Language Institute - Monterey, CA.
DoD Department of Defense
EC-121 A reconnaissance aircraft used during the Vietnam War by both the Air Force and Navy. C-121s were the military version of the Lockheed Constellation.

An element identifies Air Force personnel on duty with agencies outside the Department of the Air Force that are the "Air Force Element" of the agency where they perform duty. (AFI 25-201, 18 OCT 13)

With respect to the relationship between USAFSS and NSA, the "Air Force Element" would be USAFSS (and its successors through AFISRA) and NSA would be the agency "outside the Department of the Air Force".

ELINT Electronic Intelligence. Consists of information derived from intercepting and monitoring the adversary's non-communication emitters. It exploits the adversary's radar, beacons, and other non-communication signals, allowing friendly forces to locate radars and air defense systems over a wide area.
ESC Electronic Security Command. The second iteration of USAFSS (1979-1991)
ESS Electronic Security Squadron
ESSA Electronic Security Systems Assessment (USAF's 21st century COMSEC). ESSA includes monitoring, collection, analysis, processing and reporting of Department of Defense (DoD) telecommunications such as telephone, computer-to-computer, facsimile, radio, and wireless transmissions to determine critical information deficiencies, weaknesses and vulnerabilities that could potentially be compromised and exploited by hostile intelligences services.
EW Electronic Warfare
FAC Forward Air Controller
FISINT Foreign Instrumentation Signals INTelligence is intelligence from the interception of foreign electromagnetic emissions associated with the testing and operational deployment of foreign aerospace, surface, and subsurface systems. FISINT can provide technical details of foreign weapons system development. allowing US forces possible insights into foreign technological advances.
Front-ender Any aircraft cockpit crewmember (pilot, co-pilot, navigators, flight engineer) on USAFSS reconnaissance reconnaissance missions. (compare back-ender)
FTV "Freedom Through Vigilance" – Motto of USAFSS and successor commands (adopted 27 July 1963; authored by Lt Mike Egan)
FTVA Freedom Through Vigilance Association
GCI Ground control (or controlled) intercept (or interception). GCI is an air defense system whereby one or more radar stations or other observational stations are linked to a command communications center which has the capability to guide interceptor aircraft to (typically) an airborne target.
GEOINT Geospatial Intelligence

Greenwich Mean Time. Since mid-20th century, the term GMT has largely been displaced by UTC or "Coordinated Universal Time". See UTC.

HF High Frequency
HQ Headquarters
HUMINT Human Intelligence. The Air Force re-established the field of human intelligence in May 2007 as part of the Air Force's ISR transformation efforts. This was the first HUMINT unit in the Air Force since 1995. The 25th Air Force reintegrated HUMINT into our arsenal to meet the warfighting requirements.
IFEL Institute of Far Eastern Languages, Yale University. IFEL (which was shuttered in 1966) is where many USAFSS linguists first learned their basic (or higher) language. IFEL mostly taught Chinese, as well as Korean. Following the closure of IFEL, almost all USAF language training has been taught, as it is today, at the Defense Language Institute, Foreign Language Center, in Monterey, CA.
INSCOM (USINSCOM) Intelligence & Security Command (United States Army Intelligence & Security Command). Successor organization to the Army Security Agency (ASA), which was redesignated in 1977 using ASA elements and other intelligence elements of the US Army.
IRAN Acronym for Inspection and Replacement as Necessary. This is where ACRP aircraft are sent for upgrades, reconfigurations, etc.
ISR Intelligence, Surveillance and Reconnaissance: "An activity that synchronizes and integrates the planning and operations of sensors, assets, processing, exploitation, and dissemination systems in direct support of current and future operations. This is an integrated intelligence operations function." ISR consists of separate elements but requires treatment as an integrated whole in order to be optimized.
MIA/KIA Missing in action/Killed in action. In 1976, the Pentagon declared all persons who were listed as MIA as "Killed in action, body not recovered" indicated by the abbreviation MIA/KIA.
Monkey Mountain

"Monkey Mountain" was a name the US military gave to an area on the top of a small mountainous peninsula about 8 miles (14 km) NE of Da Nang AB (and, yes, there were monkeys on the mountain).

USAF and Marine installations predominated, but the Naval Security Group also had a small installation, and the Armed Forces Vietnam Network (re: "Good Morning, Vietnam" movie) had one of their many transmitters there, too.

The two main Air Force units at Monkey Mountain were Det 2, 6925th Security Group (the SIGINT site), and the radar site run by the 620th Tactical Control Squadron (TCS) which was technically a Control and Reporting Post (CRP — later upgraded to a Control and Reporting Center) basically acting as an air route traffic control center with the call sign "Panama".

NARA National Archives and Records Administration (same as National [Military] Personnel Records Center). Located in St. Louis, MO
NPRC National [Military] Personnel Records Center – SEE NARA
NPS National Park Service (Used here in the context that the Vietnam Wall in Washington, D.C., is overseen by the NPS.)
NRO National Reconnaissance Office
NRP National Reconnaissance Program
NSA (.../CSS) The National Security Agency[/Central Security Service]. Founded in 1952, NSA/CSS is part of the Department of Defense and a member of the US Intelligence Community. NSA/CSS is a DoD Combat Support Agency and is the US Government lead for cryptology, and its mission encompasses both Signals Intelligence (SIGINT) and Information Assurance (IA) activities.
The Central Security Service (CSS), a companion organization to NSA since its creation in 1972, conducts SIGINT collection, processing, analysis, production, and dissemination, and other cryptologic operations as assigned by the Director, NSA/Chief, CSS (one individual). NSA/CSS provides SIGINT and IA guidance and assistance to the DoD Components (e.g., USAFSS and now 25 AF), as well as national customers.
NSG Naval Security Group. From 1935 - 2005, NSG was the US Navy's Cryptologic operating agency/component. In 2009, the US Fleet Cyber Command/US Tenth Fleet were established simultaneously (under one commander) and are jointly responsible for intelligence activities for the US Navy.
NVP National Vigilance Park, NSA, Ft. Meade, MD
OL Operating Location. Similar to a detachment, but smaller, and used when a detachment seems unnecessary. Operating locations do not have commanders; usually, the highest ranking individual is placed in charge.
OPSEC Operations Security
PCS Permanent Change of Station (compare "TDY")
PSYOPS Psychological Operations
Queen Bee Original project name used for RC-130B-II ACRP missions in SEA during the Vietnam War (1964 - fall of '65). Changed in the fall of '65 to "Silver Dawn" due to suspected compromise (the project name was classified at the time) and finally "Commando Lance" (Feb '67 - 31 Dec '67).
Rivet Gym Project name for EC-121 airborne warning and control aircraft in SEA.
Rivet Joint Project name for present-day RC-135V/W airborne reconnaissance platform/missions conducted by 25 AF.
Round-robin A flight of any type — for example, reconnaissance or training flights — that takeoff and land at the same location.
RSM Radio Squadron Mobile
RTAFB Royal Thai Air Force Base
RVN Republic of Vietnam. South Vietnam.
RVNAF Republic of Vietnam Air Force South Vietnam's Air Force.
SAC Strategic Air Command
SAM Surface-to-air Missile
SCA Service Cryptologic Agency. SCA was the term for the intelligence collection and delivery components of the Air Force, Navy, and Army on behalf of the NSA since WWII. The name was later changed to "Service Cryptologic Elements", and is currently, "Service Cryptologic Components" (see SCC, below), although the term "elements" is used within the context of SCC.

Service Cryptologic Component. Term used to designate components of the Army, Navy, Marine Corps, Air Force, and Coast Guard assigned to the Central Security Service (CSS) for the conduct of cryptologic operations funded by NSA/CSS.

Air Force Service Cryptologic Component (AF SCC, which is now the 25 AF) is the "lead for AF cryptologic activities and has management oversight of those elements of the USAF performing cryptologic functions. This applies to the cryptologic staff of the [25th Air Force*], its subordinate elements, and cryptologic elements assigned to other USAF organizations. The [25 AF*] Commander is the AF/SCC Commander and principal USAF advisor to DIRNSA/CHCSS for USAF cryptologic matters." Additional information is detailed in the Air Force Instruction entitled AIR FORCE SERVICE CRYPTOLOGIC COMPONENT (AF SCC), AFI 14-128.

* AFI 14-128 happens to be dated before the redesignation of AFISRA to 25 AF, so the AFI literally calls out the AFISRA staff, commander, etc., NOT the 25 AF. But according to wording in a companion AFI, 14-125, which was "Certified Current on 11 March 2015," indicates that the above version [of AFI 14-128] is still in effect as it stands ... at least as of 11 MAR 15, that is. Whew!)

SCE Service Cryptologic Element (see SCC, above)
SEA Southeast Asia
SG Security Group. A "Group" is a formal USAF organization. See "Types of Air Force Organizations" for more information.

Signals Intelligence. The category of intelligence which includes, individually or in combination, all communications (COMINT), electronic (ELINT), or foreign instrumentation signals intelligence (FISINT).

NSA/CSS: "SIGINT is a category of intelligence that includes transmissions associated with communications, radars, and weapons systems used by our adversaries. It complements other forms of intelligence that are the responsibility of other US agencies in the Intelligence Community." (Source: NSA/CSS website)

From NSA/CSS: "The Signals Intelligence mission collects, processes, and disseminates intelligence information from foreign signals for intelligence and counterintelligence purposes and to support military operations." (Source: NSA/CSS website)

Silent Warriors

In the genre of all intercept operators of USAFSS and each of its successor organizations as well as their counterparts in the other services — the term Silent Warriors refers to all those who performed (or are currently performing) critical intelligence-gathering missions in silence ... whether in the air or on the ground; whether in times of conflict or the "peaceful" years of the Cold War; or in the present day.

Its origin is unknown, but the reference was apparently first used to describe the men (and, now, women) of USAFSS and its successor organizations during the memorial dedication at NSA's National Vigilance Park at Fort Meade, Maryland, in recognition of the men who perished in the shootdown of the USAFSS C-130A, tail number 91528, over Soviet Armenia in 1958.

HISTORY: The term "Silent Warrior", as one would expect, is not unique to US military intercept operators; it has been around for literally centuries. Some say it was first coined by Euripides in one his plays, and has since been widely used to refer to Native Americans, Joe Frazier (in a poem by Mohammed Ali), snipers in Vietnam, song titles (Enigma), an album title ("XIT"), and more.

Silver Dawn Project Name for RC-130B-II ACRP missions in SE Asia during the Vietnam War (fall '65 - Feb '67). Known previously as "Queen Bee" (from 1963 - fall of '65) and subsequently as "Commando Lance" (Feb '67 - 31 Dec '67).
Sqdn Squadron. See "Types of Air Force Organizations" for more information.
SS Security Squadron. The 6988th was a Security Squadron. In very general terms, the hierarchy of USAF organizations, from the smallest "unit" (i.e., not a detachment or operating location) up, is Flight, Squadron, Group and Wing.
SW Security Wing
TDY Temporary Duty. Temporary assignment for anyone in the military to a location other than where s/he is permanently assigned for a fixed period of time, typically less than 180 days. Compare to "PCS".
UHF Ultra High Frequency. The frequency range from 300-3000 MHz in the frequency spectrum. Cell phones, for example, use select frequency ranges in this band in the US (see VHF)

Coordinated Universal Time. UTC, like GMT, nominally reflects the mean solar time along the Earth's prime meridian (0° longitude at Greenwich England). UTC is calculated by, and is the average of, over 200 highly accurate atomic clocks located throughout the world. Also known as Zulu time (0000Z = 0000 UTC) — used mostly in the military, civil aviation, weather reporting, etc.

Trivia: The abbreviation "UTC" is a compromise between CUT (the English abbreviation) and TUC — the French abbreviation (Temps universel coordonné). The French, being the French, also had their own "prime meridian" ("Why the hell should it be in England?") but that lasted only for a few months. At the time (late 19th Century), almost 75% of all the nautical charts in the world were based on the Prime Meridian being at Greenwich.

USAF United States Air Force/US Air Force
USAFSS United States Air Force Security Service (sometimes "AFSS")
VA US Department of Veterans Affairs (formerly the Veterans Administration 1930-1988, and prior to 1930, the Veterans Bureau. The VA was elevated to a cabinet-level department by President Ronald Reagan and retained the "VA" moniker.)
VFW Veterans of Foreign Wars

Very High Frequency. The frequency range from 30-300 MHz in the frequency spectrum.

VHF and UHF (300-3000 MHz) offer higher voice quality and clarity and are virtually devoid of atmospheric interference ("static") compared to lower frequencies (High Frequency [HF] & Low Frequency [LF]). Most air-to-air and air-to-ground radios since the end of WWII are in the VHF and/or UHF frequency bands. Starting about 30 MHz, radio waves become "line of sight". Frequencies below 30 MHz can "bend" or bounce off various layers of the atmosphere, enabling long-range communication.

YUP Yale University Press Main site.
Yale University Press Links directly to Chinese language books.
YVA Yale Veterans Organization A non-partisan, non-political veterans organization comprised Yale alumni, IFEL graduates, students, faculty, and staff who have served or are currently serving in the US or allied armed forces. Membership is free for those individuals in any of the above groups.


Freedom Through Vigilance