crankshafts. By 1930 the Soviet helicopter pioneers, Boris N. Yuriev and Alexei M. Cheremukhin, both employed by Tsentralniy Aerogidrodinamicheskiy Institut (TsAGI, the Central Aerohydrodynamic Institute), constructed one of the first practical single-lift rotor machines with their TsAGI 1-EA single rotor helicopter, powered by two Soviet-designed and built M-2 rotary engines, themselves up-rated copies of the Gnome Monosoupape rotary engine of World War I. The TsAGI 1-EA set an unofficial altitude record of 605 meters (1,985 ft) with Cheremukhin piloting it on 14 August 1932 on the power of its twinned M-2 rotary engines. Use in cars and motorcycles Although rotary engines were mostly used in aircraft, a few cars and motorcycles were built with rotary engines. Perhaps the first was the Millet motorcycle of 1892. A famous motorcycle, winning many races, was the Megola, which had a rotary engine inside the front wheel. Another motorcycle with a rotary engine was Charles Redrup's 1912 Redrup Radial, which was a three-cylinder 303 cc rotary engine fitted to a number of motorcycles by Redrup. In 1904 the Barry engine, also designed by Redrup, was built in Wales: a rotating 2-cylinder boxer engine weighing 6.5 kg was mounted inside a motorcycle frame. The early-1920s German Megola motorcycle used a five-cylinder rotary engine within its front wheel design. In the 1940s Cyril Pullin developed the Powerwheel, a wheel with a rotating one-cylinder engine, clutch and drum brake inside the hub, but it never entered production. Other rotary engines Besides the configuration of cylinders moving around a fixed crankshaft, several different engine designs are also called rotary engines. The most notable pistonless rotary engine, the Wankel rotary engine has been used by NSU in the Ro80 car, by Mazda in a variety of cars such as the RX-series, and in some experimental aviation applications. In the late 1970s a concept engine called the Bricklin-Turner Rotary Vee was tested. The Rotary Vee is similar in configuration to the elbow steam engine. Piston pairs connect as solid V shaped members, with each end floating in a pair of rotating cylinders clusters. The rotating cylinder cluster pairs are set with their axes at a wide V angle. The pistons in each cylinder cluster move parallel to each other instead of a radial direction, This engine design has not gone into production. The Rotary Vee was intended to power the Bricklin SV-1. See also Petrol engine Monosoupape engine Manly–Balzer engine