Information on the EC-121S

Written By

Harold L. Bowman, CMSgt. PaANG


The genesis of the EC-121S was in 1965 when the US Navy started broadcasting AM radio from a converted aircraft to the Dominican Republic.  It was during the attempt to overthrow the government in support of the deposed President Juan Bosch. The aircraft with an AM transmitter, a special generator and a wire that was deployed and retrieved from underneath the aircraft providing a vertical antenna, reportedly was very successful. Much of the broadcast was made up of baseball games, music and “information to civilian population” in support of the government.


The Navy, believing it had considerable success with this capability, set out to design a new EC to meet it’s needs. The aircraft had a 10Kw LF transmitter, (for submarine communications) a 10 Kw MF transmitter, (for commercial AM broadcasting) two 10 Kw HF transmitters one of which could be connected to a 40Kw final amplifier. A special designed and manufactured 2.5 Kw with 4 different amplifiers VHF/UHF capable of broadcasting tactical AM, commercial FM and TV channels 2-13 on the US standard. The unique exterior of the “S” model is not always recognized and often confused with the “R” model that had a radar mission. First it was painted in “Air Line” colors with a white top, dark blue center, a gray bottom with fine gold detail lines between the colors. There were two large radomes on the bottom and one on the top that housed VHF broadcast antennas some of the. Several smaller radomes populated the bottom and top for UHF Connie001.jpg (134049 bytes)broadcast. Originally toward the front of the fuselage were two large masts that connected wires to the tail for the high power HF transmitters. These were removed in the early 70’s after one aircraft had the area fail causing a rip in the aircraft skin during a flight. There were two additional HF antennas configured between the wing tip, the horizontal stabilizer and the aft area on the cabin called the “Bat Wing Antennas”.


As the story goes the Joint Chiefs reviewed the program under a mid 1960’s alignment of missions and requirements of each of the services determined that the mission should be operated by the Air Force. The Air Force did not want the mission seeing it as a training nightmare with little long-term stability of forces. It was during this same time frame that the 168th Military Airlift Sq. flying C-121’s located at Olmsted Field in Middletown Pa. was to be decommissioned. The Commander and Staff heard of this new mission and with much effort they were able to win the mission and be redesignated the 193rd Connie 005.jpg (344248 bytes)Tactical Electronic Warfare SQ. (193rd TEW Sq.) An interesting problem arrived before the aircraft. It was a classified mission and aircraft! The existing crews and all the new members in the mission crew about 50 operators/technicians would need to have at least   Secret Clearances.  This would be a large undertaking since the training for the first crews started in 1968 in Nyack NY with the delivery of the first aircraft in 1968.


One thing for sure it was originally a Navy project. The initial manuals delivered to the 193rd were written for the Navy using port and starboard instead of left and right. Another issue that arrived with the aircraft was that the weight of the equipment prevented the full loading of gas thus severely limiting the range of the aircraft. The initial weight reduction included the removal of the LF transmitter and 23,000 ft of wire from the spool that fed the vertical antenna leaving 2,000ft thus aligning the equipment to broadcast on both civilian frequencies and HF/VHF/UHF tactical military nets.


Kw Kilo watts/LF Low Freq/ MF Medium Freq/ HF High Freq/VHF Very High Freq/ UHF Ultra High Freq/ 

Copyright by Harold Bowman

Note: The successor to the EC-121S, the C-130 Cornet Solo
flew in Iraq in the war 2003.