Classic Project: Sikorsky R4 Helicopter

Author(s): N. Smith
Source: Volume 9, Issue 3, April 2014, p. 100 – 101
DOI: 10.1049/et.2014.0338 , Print ISSN 1750-9637, Online ISSN 1750-9645

Published

Sikorsky R4 - the world's first production helicopter.