1 May from the headquarters and headquarters company (HHC) of the 278th Brigade. The 1st and 2nd Squadrons were redesignated from existing units on the same day. The 2nd Battalion, 117th's HHC was redesignated as the HHT of the 278th ACR's 1st Squadron at Athens. 1st Squadron was mostly redesignated from the 2nd Battalion. The 1st Squadron's Troop A was redesignated from Company B at Cleveland, Troop B from the Support Company at Sweetwater, Detachment 1 of Troop B from Company C at Lenoir City, Troop C from the 376th Signal Company at Newport, Company D from Detachment 1 of the 130th Military Police Company at Oak Ridge, and the Howitzer Battery from Company A at Maryville. The headquarters and headquarters detachment of the 330th Transportation Battalion at Kingsport was redesignated as the HHT of the 2nd Squadron. Troop E was redesignated from the 1130th Transportation Company at Morristown, Troop F from the 1174th Transportation Company at Bristol, Troop G from Detachment 1 of the 376th Signal Company at Greeneville, Company H from the 130th Military Police Company at Clinton, and the Howitzer Battery from Detachment 1 of the 117th's 2nd Battalion at Knoxville. On 30 September 1978, the 777th Maintenance Company (GS), a separate unit stationed in Knoxville at the Knoxville Armory, was reorganized and redesignated as the Air Troop of the 278th. The unit was later relocated to Alcoa. A year later, the 450th Assault Helicopter Company, stationed in Smyrna, was reorganized and redesignated as the Attack Helicopter Troop of the regiment. The headquarters and headquarters detachment of the 130th Aviation Battalion and the 1155th Transportation Company (Aviation Intermediate Maintenance) were attached to the 278th by the State Area Command to serve as command and control for the separate air troop and attack helicopter troop. On 1 February 1980, the HHC of the 3rd Battalion, 117th at Cookeville was redesignated as the HHT of the 278th ACR's 3rd Squadron. 3rd Squadron was mostly redesignated from the 117th's 3rd Battalion. Troop I was redesignated from Company A at McMinnville, Detachment 1 of Troop I from Detachment 1 of Company A at Smithville, Troop K from the Support Company at Livingston, Detachment 1 of Troop K from Detachment 1 of Company B at Jamestown, Troop L from Detachment 1 of the Support Company at Crossville, Detachment 1 of Troop L from Detachment 1 of Company C at Harriman, Company M