R-101 Credit - © Mark Wade

Russian derivative of the German Wasserfall, an interim design between the R-101 and R-108. The missile did not reach flight test stage before it was cancellation in 1951.

The R-109 was an interim version of the R-101, between the R-101 and the ultimate R-108, which would use air-pressurised kerosene fuel and a new Russian feed system, resulting in a more economical size and weight of pressurant bottles. This version had a payload of 500 kg and a longer range than the German Wasserfall or the R-101. It also featured more compact radio guidance and electronics, and auto-stabilisation in flight. There were improvements as well in camouflage and anti-countermeasures.

Manufacturer: Sinilshchikov.

• Yeftifyev, M D, Iz istorii sozdaniya zenito-raketnovo shchita rossii, Vuzovskaya kniga, Moscow, 2000. Comprehensive history of development of the development of surface-to-air and anti-ballistic missiles in the Soviet Union, with summaries of work in other countries as well. Accessed at: http://www.eastview.com/xq/ASP/sku=A2010232/f_locale=/Evtif'ev/MD/Moskva/Russia/Russian/qx/russian/books/product.asp.