I would first like to thank the Royal Aeronautical Society for inviting Entwicklungsring Süd to give this lecture on the development work on vertical take-off aircraft. The Southern Germany Development Group—Entwicklungsring Süd—the abbreviation of which is EWR—was founded at the beginning of 1959 for the purpose of developing a vertical take-off and landing strike-fighter, the VJ 101, and was an association of the three firms: Bölkow-Entwicklungen KG, Ernst Heinkel Flugzeugbau GmbH und Messerschmitt AG. Heinkel has recently left the association and joined Vereinigte Flugtechnische Werke (VFW), Bremen. The work is now carried on by the remaining two firms, Bölkow and Messerschmitt. Since July 1965 EWR has the form of GmbH (Ltd).