Hong Kong Study Circle Specialising in the Philately of Hong Kong and the Treaty Ports Founded 1951 

Exhibits


The History of Rotary Wings by Philippe Orsetti

Contents
Synopsis
Section 1. Early History
Pages 2 to 16
Section 2. Helicopter Development Through Its Manufacturers
Pages 17 to 48
Section 3. Diversity of Helicopter Usages
Pages 49 to 80