Here's what I found out about the Smyrna Airport.
Units:
Army Aviation Support Facility #1
4th Squadron, 278th Armored Calvary Regiment
Smyrna Airport currently operates as a joint use training facility with the Tennessee Army National Guard helicopter unit, AASF#1 (Army Aviation Support Facility #1). AASF#1 operates 60 helicopters with 300 full time National Guard personnel. The airport also serves as a C-130 training facility for the 118th Air Wing of the Air National Guard from Nashville as well as C-141 training from Memphis Air National Guard. Smyrna Airport also serves as a hurricane evacuation point for military facilities along the Gulf and East Coasts.
The Tennessee Army National Guard leases part of the airport to maintain the Grubbs/Kyle Training Center and 24 different units, 1,270 assigned National Guard personnel, 162 of which are full time, and numerous aircraft.
Here's the link for the above post, along with some more pertinent info.
http://www.globalsecurity.org/military/facility/smyrna.htm
Located twelve nautical miles south of Nashville Airport, Smyrna Airport is the "reliever" airport for Nashville. With over 1,700 acres, Smyrna Airport is the third largest airport in Tennessee and the busiest general aviation airport in Tennessee. Smyrna Airport users have, within ten miles, access to rail and three interstate systems which transverse Middle Tennessee. Smyrna Airport is located in the geographic center of Tennessee and more importantly the center of the eastern United States. Eighty percent of the United States population lives within a 700 mile radius of Smyrna. These factors influence the location of industry in the Smyrna area.
Excellent findings and you were quick!