This is a beautiful Souvenir Sheet, issued in Burundi in 2012, featuring different models of helicopters. The sheet includes images of the twin-turbine transport/gunship Mil Mi-8, the twin turbine turboshaft U.S. Navy Sikorsky S-MH-60S Seahawk, and Leonardo da Vinci's design for his "aerial screw." The stamp includes an image of the medium transport/utility U.S. Army Sikorsky S-70A Firehawk. The sheet is Scott catalog #1088, and is Post Office fresh, mint never hinged, and F/VF.