History of Signals Intelligence

in the U.S. Air Force

USAFSS - The Beginnings

He cleaned out his desk, said his good-byes to old friends and headed for the front door of Air Force Security Service Headquarters at Brooks Air Force Base, San Antonio, Texas. Suddenly, he heard the inimitable voice of Colonel Robert H. Augustinus' secretary, "Lieutenant Harriger, the colonel must talk to you immediately."

It was a hot afternoon in San Antonio on 25 June 1950. Hours earlier, events began unfolding 14 time zones away in Korea that would change Russell "Hop" Harriger's life and the lives of hundreds of thousands of Americans forever. The North Korean army had invaded South Korea and was marching on Seoul, the South Korean capital. The United States Air Force Security Service (USAFSS) was about to go to war, and for the third time in a decade, Hop Harriger's plans to attend law school were put on hold. Faced with its first operational crisis, USAFSS had other plans for Lt. Harriger and other assigned personnel who were approaching the end of their active duty military commitments.

Participation in the Korean War truly would be its baptism under fire for Security Service, a totally new command within the U.S. Air Force, which itself had been an independent branch of the United States armed forces only since 1947.

U.S. Air Force - A Brief History

The United States Air Force had its beginning as the Aeronautical Division of the U.S. Army Signal Corps on 1 August 1907, and the Corps accepted the Army's first airplane two years later (2 August 1909). Less than six months later (19 January 1910), a Signal Corps pilot dropped three two-pound bags of flour in an attempt to hit a target, the Army's first bombing experiment. Thirty-three years later, Signal Corps communications intelligence (COMINT) platoons were providing targeting information in support of Allied bombers carrying out bombing raids against Nazi Germany.

The Aviation Section of the Signal Corps was created on 18 July 1914, and five months later a couple of Signal Corps lieutenants demonstrated two-way air-to-ground radio communications. Thirty years later, Technical Sergeant Herman L. Roesler was flying as a voice interceptor (German linguist)-providing internal advisory warning support-during U.S. Army Air Corps B-17 bombing missions against German facilities in Europe. Japanese-American (Nisei) linguists performed similar airborne duties aboard Air Corps aircraft in the Far East, intercepting Japanese air force and air defense communications in 1945.

On 24 May 1918, the U.S. Army Air Service was organized, giving the air arm of the army parity with other army branches. After WW I, Brigadier General William (Billy) Mitchell and other airpower pioneers spoke out forcibly for an independent air force. Envisioning aviation as a separate strike force, they opposed the Air Service remaining an arm of the U.S. Army. For speaking out so vehemently, Mitchell was court-martialed in 1925 and demoted, and he resigned from the service. Later he was vindicated and declared a hero by U.S. Air Force leaders.

Congress and the army rejected Mitchell's argument for an independent air force. However, on 2 July 1926, the Air Service became a separate combat arm-the U.S. Army Air Corps-equal in status with the infantry, cavalry and artillery. With the threat of world war looming in Europe and the Far East in 1938-39, the Air Corps budget grew dramatically. In 1939, the U.S. defense budget for fiscal year 1940 authorized $300 million to support an Air Corps consisting of 6,000 planes, 3,203 officers and 45,000 enlisted troops.

With the buildup in airpower, on 20 June 1941, the War Department reorganized its ground forces and created as its air arm the U.S. Army Air Forces. However, from 9 March 1942 to 18 September 1947 the Army Air Corps continued to operate as a combatant arm of the Army Air Forces.

The National Security Act dated 26 July 1947 created the U.S. Defense Department and laid out provisions for reorganizing the War Department. The Department of the Air Force was created on 18 September 1947, with Army Air Forces personnel, aircraft and facilities transferred to the new U.S. Air Force. Soon AAF troops wearing olive drab uniforms and brown shoes became Air Force airmen in blue uniforms and black shoes. However, the Army Air Forces radio squadrons mobile-the air arm's communications intelligence resources-remained in the Army Signal Corps as Army Security Agency resources until 1949 when the RSM's were transferred to the newly created U.S. Air Force Security Service.

U.S. Air Force Security Service

An Overview

The United States Air Force Security Service was created as a separate Air Force command on 20 October 1948; however, the history of USAFSS would be incomplete without addressing its predecessor entities and successor commands. Army Signal Corps radio intelligence companies (aviation) were activated in World War II expressly to intercept enemy air force communications and provide "radio intelligence" to American air force field commanders.

The signal radio intelligence company (aviation) evolved into the radio squadron mobile. An RSM was attached to and supported a numbered Air Force-for example, the 3rd RSM supported the Ninth Air Force in Europe from the D-Day Invasion at Normandy, France, until the end of the war. Other Signal Corps entities monitored American military communications-communications security or COMSEC during WW II. The mission that USAFSS inherited in 1949 was essentially those two activities-providing radio intelligence (aka communications intelligence and signals intelligence) and COMSEC support to Air Force commanders.

Over the years, the Air Force communications intelligence mission evolved to keep pace with technology and changes in enemy operations. Before World War II, almost all military communications by radio (audible comms) were transmitted using Morse code and fairly low level techniques to encrypt messages. However, as less bulky, more reliable radios became available-including mobile units-voice communications increased dramatically, creating an immediate shortage of trained linguists and voice interceptors. That linguist shortage exists to this day in the intelligence community.

The deployment of radar during World War II added to the complexities of the Air Force intelligence mission, as did the introduction of multichannel communications and computer-controlled weapons systems in the 1950's and 1960's. The signals intelligence (SIGINT) environment now included communications, electronic and data transmissions. By the late 1970's the Air Force SIGINT mission had expanded to include the use of command, control and communications countermeasures (C3CM), and USAFSS became the Air Force Electronic Security Command (ESC) in 1979.

Further changes in communications technology-advent of personal computers, email and widespread usage of cellphones-and the end of the Cold War resulted in other changes in the signals intelligence mission and a realignment of the U.S. Air Force intelligence community. The Electronic Security Command was redesignated the Air Force Intelligence Command in 1991. After additional changes, the AFIC became the Air Intelligence Agency two years later. Finally on 8 June 2007, a newly activated Air Force Intelligence, Surveillance and Reconnaissance Agency (AFISRA) replaced the AIA. Thus, the lineage of U.S. Air Force signals intelligence runs from the Army Air Forces signal radio intelligence company (aviation) in 1942 to USAFSS (1948), ESC (1979), AFIC (1991), AIA (1993) and finally to AFISRA (2007 to Present).

Book Layout

The majority of FREEDOM THROUGH VIGILANCE addresses the Air Force Security Service (1948-1979), with limited coverage of ESC, AFIC, AIA and AFISRA. "FTV" is divided into four volumes. Volumes I, II and III chronicle the U.S. Air Force Security Service SIGINT ground-site histories during the Cold War and females in USAFSS. Volume IV will address USAFSS airborne SIGINT reconnaissance operations.

The author struggled with formats, event groupings and layout that would most clearly present our USAFSS history, and in the end, settled on a hybrid approach. I also grappled with level of detail and number of photographs included in this product. The trade-off was to eliminate significant amounts of information (and photos) from the manuscript and publish a single volume or retain historic relevance and publish multiple volumes. I chose the latter option. To the extent feasible, events are covered geographically then chronologically by individual units (events) within a specified area.


Chapter Layout
Volume I
Chapter 1   Army Air Force Ground-based COMINT & COMSEC in WW II
Chapter 2   USAFSS General History
Chapter 3   Female Contributions to USAFSS & Succesor Organizations
Volume II
Chapter 4   USAFSS in Germany & Austria
Chapter 5   USAFSS in Turkey, North Africa (Libya), Greece, Italy & Pakistan
Chapter 6   USAFSS in the UK (England & Scotland)
Volume III
Chapter 7   USAFSS in Alaska
Chapter 8   USAFSS in the Far East, including Support in Korean War & Vietnam War
Volume IV
Chapter 9   Airborne SIGINT Reconnaissance in World War II
Chapter 10   Early USAFSS Airborne Reconnaissance
Chapter 11   6916th Security Squadron History
Chapter 12   6988th Security Squadron History
Chapter 13   6985th Security Squadron History
Chapter 14   History of USAFSS "Navy"
Volume V
Chapter 15   USAFSS Spanish Flyers
Chapter 16   6949th Security Squadron History
Chapter 17   6954th Security Squadron History
Chapter 18   6990th Security Squadron History
Chapter 19   6994th Security Squadron History
Chapter 20   Miscellaneous Airborne ISR/EW
--   25th Intelligence Squadron
--   169th Intelligence Squadron
--   Compass Call


While Volume I provides a general history of the Air Force Security Service command and female contributions to the USAFSS mission, the real "meat" of Freedom Through Vigilance-the history of worldwide USAFSS field operations-lies in Volumes II, III, IV and V. Appendix A of all five volumes contains a list of acronyms and abbreviations used in Freedom Through Vigilance, and Appendix B is a list of worldwide locations at which USAFSS units operated (1949-1979).

USAFSS Unit Locations List

Created by Air Force Security Service (or Electronic Security Command) Headquarters from official records about 1979, the USAFSS Unit Locations List (Appendix B) should be invaluable to USAFSS veterans desiring to refresh their memories regarding locations/units in which they served during the period 1949-1979. The units included in the list are valid, albeit the list is not all inclusive. For example, many of the early detachments created overseas by radio squadrons mobile in the early 1950's are not on the list, perhaps because copies of special orders activating those units may not have found their way to the USAFSS HQ archives used to create the list. We are indebted to retired USAFSS Major Frank Clark for providing a copy of this "Location/Unit/Date" listing for our USAFSS history. In 2010, Clark recalled that he had obtained the unclassified listing from the USAFSS history office shortly before he retired in 1980.

Index & Endnotes

Each volume also contains an index. Additionally, source documents and other clarification are cited in endnotes. The author takes responsibility for all errors.

Where to Purchase

"Freedom Through Vigilance" is available directly from the author via email or from Infinity Publishing.

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