The S-3, S-4, and S-5 followed in quick succession, each a refinement of its predecessor, and each adding to Sikorskys’ piloting experience.
Finally, by the summer of 1911, in an S-5 with a 50-horsepower engine, Sikorsky was able to remain in the air for more than an hour, attain altitudes of 1,500 feet (450 metres), and make short cross-country flights. This success earned him International Pilot’s License Number 64.
Span: top 39’4″ bottom 29’6″ or 27’11”
Length: 27’11” or 26’3″
Weight loaded: 970 lb
Speed: 78 mph
All Aero 