TRIA
Telemetry Range Instrumentation Aircraft
At some point after the ARIA aircraft procurement, four additional KC-135Bs, aircraft 61-0331, 61-2664, 62-4128, and 62-4133, were obtained and structurally modified. They were nearly visually identical to the ARIA aircraft, except for engines installed and the planes displaying "US AIR FORCE" on the fuselage. In contrast, the ARIA Aircraft showed "UNITED STATES OF AMERICA." The history of the mission of these TRIA, Telemetry Range Instrumentation Aircraft, has been lost to time. The modification timeline is unknown, but I do know that two of these aircraft had the complete ARIA package installed and would supplement the ARIA program. The third aircraft eventually modified as an RC-135S, and the fourth aircraft extensively modified to detect and analyze nuclear explosions and their related electromagnetic pulses.
Credit: Randy L. Losey