I will describe in this paper some features of current Boeing-Vertol production helicopters that I have selected as those which strike me personally as being of particular engineering interest. But first just to provide some perspective on the subject I would like to summarise the background of the present Vertol Division of The Boeing Company. The Company was formed in 1944 as the Piasecki Aircraft Corporation and its first product was the HRP Tandem Rotor Helicopter, which first flew in 1945. This was followed by the HUP in 1948, the H-21 in 1952 and the H-16 in 1953. In 1956 the Company was renamed Vertol and the next aircraft to fly was the Model 107 Prototype in 1958. In 1960 Vertol was acquired by Boeing and became the Vertol Division. The currently manufactured models about which I am going to talk, are the 107 series (now mostly in production as the US Marine Corps Model CH-46, Sea Knight) and the 114 series (in service with the US Army as the CH-47, Chinook) of helicopters.