Area 51 YF-117A. At 6:05 am on 18 June 1981 Lockheed Skunk Works test pilot Hal Farley lifted the nose of YF-117A "79–780"' off the runway of Area 51. Meanwhile, Tactical Air Command (TAC) decided to set up a group-level organization to guide the F-117A to an initial operating capability. That organization became the 4450th Tactical Group (Initially designated "A Unit"), which officially activated on 15 October 1979 at Nellis AFB, Nevada, although the group was physically located at Area 51. The 4450th TG also operated the A-7D Corsair II as a surrogate trainer for the F-117A, and these operations continued until
Utah State Route 51 of the oldest grade separated interchanges in Utah still in use. Although portions of Interstate 15 were constructed in 1955, the Beck Street interchange (I-15/US-89) is the only original structure from 1955 still in use. Utah State Route 51 State Route 51 is a short highway completely within Utah County in northern Utah that connects SR-147 to US-89. The highway runs for three miles (5 km) and is an old routing of U.S. Route 91. The route begins at the intersection of 400 North (SR-147) and Childs Road in Spanish Fork, SR-51 heading northeast as a two-lane undivided highway on