Sikorsky S 5

The Sikorsky S-5 was an early design by Igor Sikorsky, completed in late April 1911, with a 50 hp (37 kW) Argus water-cooled engine. The S-5 was tested in a series of 20 to 30-second straight-line flights, over a period of three weeks, before the designer was able to make what he called his first real flight of four minutes, in a circuit of the field, on 17 May 1911.

After outperforming Russian Army aircraft during manoeuvres watched by Czar Nicholas II, the S-5 earned Igor Sikorsky his first income with a series of exhibition flights during a country fair at Belaya Tzerkov, near Kiev. Between nine and ten flying hours were logged before the S-5 was lost through an engine failure.