YAK-18 at the Olympic Air Show 2012 in Olympia WA.
The Yakovlev Yak-18 was a Soviet tandem two-seat military primary trainer aircraft. Originally powered by one 119 kW (160 hp) Shvetsov M-11FR-1 radial piston engine, it entered service in 1946. It is also produced in China as the Nanchang CJ-5.
Canadian Aviation Blog
Olympic Flight Museum