'In 1913 he built & flew the first 4-engine airplane; later he built helicopters'
Igor Sikorsky
AVIATION: In 1913 he built & flew the first 4-engine airplane; later he built helicopters
In 1913 he built & flew the first 4-engine airplane; later he built helicopters
In 1913 he built & flew the first 4-engine airplane; later he built helicopters
AVIATION
Igor Sikorsky
AVIATION