Among the modifications of the Yak-18, this variant occupies, perhaps, a special place as a milestone in the development of the design. The Yak-18A appeared in 1956 as a result of equipping the Yak-18U with a more powerful engine. The idea of such a re-equipment arose in December 1946, when the Air Force, summing up the results of the control tests of the Yak-18, proposed to improve its LTX and operational qualities in its further modifications to provide for the installation of a more powerful engine (200 hp). This requirement was implemented only 10 years later, when, under the leadership of chief designer A.G. Ivchenko, the AI-14R engine was created (initially with a capacity of 220 hp, later 260 hp). Replacing the M-11FR with the AI-14R literally breathed new life into the Yak-18.It was necessary to pay for this with regular alterations of the aircraft design. In particular, since the new engine was a 9-cylinder, it was necessary to radically alter the engine frame, hood and oil system of the aircraft.