Two Sukhoi Su-27UB trainers have just turned up in the US. They're probably not the first aircraft of the type to be acquired by US operators - but are probably the first that anyone will talk about, since there have been multiple Su-27 sightings in the neighborhood of Air Force Flight Test Center Detachment 3, popularly known as Area 51.
One of the two Su-27s before delivery (Tac Air)
The two new arrivals have been acquired from the Ukraine by Reno-based Tac Air, which provides training and test support to the military. (The company was involved with testing of Raytheon's hush-hush LSRS radar, for instance.) They arrived some months ago in suburban Rockport, Illinois, in the hold of an An-124 cargo aircraft, and are being overhauled and modified (with US radios, for example) by warbird specialist Pride Air. The company says that the work is nearing completion.
Su-27 arrives in Rockport (Pride)
The new aircraft will join Tac Air's fleet of L-29 and L-39 trainers and MiG-17 fighters, and enable Tac Air to become "the first company offering fourth-generation fighter training support," the company says.