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.

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.

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.