This is the McDonnell-Douglas Queen Air test aircraft used for TERCOM flight tests jointly conducted by the Navy-Air Force team. It allows the guidance system to make fixes in real time. Because terrain contour matching is independent of aircraft speed, using an aircraft less expensive to operate is attractive. at the Dugway proving ground in Utah
U.S. Department of the Navy
<a rel="nofollow" class="external text" href="https://babel.hathitrust.org/cgi/imgsrv/download/pdf?id=mdp.39015076084030;orient=0;size=100;seq=23;num=5141;attachment=0">Fiscal year 1976 and July-September 1976 transition period authorization for military procurement</a>, Statement of Capt. Walter M. Locke, Project Manager, Sea Launch Cruise Missile, United States Navy, pt. 10, p. 5141