Advise, Assist, Control
A TACP is a Tactical Air Control Party. It is comprised of a JTAC (Joint Terminal Air Controller) and a ROMAD (essentially a JTAC in training, though the reality is ROMADs are frequently seasoned operators in their own right, having completed lengthy and arduous blocks of training and lacking only the final JTAC certification). JTACs direct the action of combat aircraft operating in CAS (Close Air Support) and other offensive operations, calling in airstrikes and gun runs like an FO or an ANGLICO Marine calls in artillery or naval gunfire. The NATO is Forward Air Controller. A typical TACP (JTAC or ROMAD or both) might be on an infantry patrol one day to coordinate immediate CAS and attached to an ODA the next day for the same reason.
The whole TACP/JTAC/ROMAD (and CCT) series of monikers often creates confusion, which isn’t surprising. A TACP is a Tactical Air Control Party. It is comprised of a JTAC (Joint Terminal Attack Controller) and supporting personnel, typically a ROMAD; though with the high demand for JTACs in the field with conventional units, many patrols are actually supported by ROMADs. They are usually a 2-man team and usually assigned to a conventional infantry patrol (usually platoon size or smaller) though they will frequently support SOF forces as well. TACP personnel are usually collocated with the unit they are supporting, so for instance you might find 2 Airmen bunked down at a COP with a particular platoon or perhaps company sized element, and those Airmen may only rarely encounter anyone else from their “own” unit during the deployment.
The difference? A JTAC is has completed JTACCQC. A ROMAD has not, although with the high operational tempo their squadrons experience, many ROMADs have a great deal of combat experience “on call”. Technically speaking, the primary difference between a JTAC and a ROMAD is that a JTAC is legally allowed to say CLEARED HOT on the radio and direct aircraft to drop their ordnance on target. ROMADs can and do talk the aircraft into position and frequently just hand control authority to a JTAC that may be miles away who (essentially relying on the ROMAD to do his job right) stays on the line long enough to clear the aircraft hot and then goes back to doing whatever he was doing (which is frequently talking CAS missions in wherever he is, if he’s not in the TOC).
The JTAC motto is ADVISE, ASSIST, CONTROL