Staff Writer (Updated: 3/20/2014):
The Yak-18 utilized a conventional configuration with a front-mounted engine (driving a two-bladed propeller assembly), single-finned tail unit and low-set monoplane wings. The main wings were fitted ahead of midships. The two crew sat in tandem under a long-running canopy. The undercarriage of early forms was partially retractable, the main legs semi-recessed under the wings and the tail wheel fixed in place.
Original production forms were designated simply as Yak-18. The Yak-18A utilized the Ivchenko AI-14 FR series engine of 260 horsepower and overtook production lines, becoming the definitive Yak-18 form. The Yak-18U was a limited-run model utilizing a retractable tricycle undercarriage. The Yak-18P ("Mouse") was a single-seat acrobatic platform, the Yak-18PM of similar scope though with retractable tricycle undercarriage and the Yak-18PS following suit but incorporating a retractable tailwheel. The sole foreign mark included the Nanchang CJ-5 of China and 379 aircraft of these were produced into 1958. China originally received the aircraft in 1950 as kits delivered from the Soviet Union for assembly before eventually turning to local factories for outright production of the design in the mid-1950s.
While a trainer by design, the Yak-18 was pressed into service as a light bomber by North Korea during the Korean War (1950-1953). Changes to the airframe were minimal for bomb racks were simply added to the fuselage centerline. Due to their slow speed, these light bomber Yak-18s were utilized by the North Koreans in night sorties - and this with limited effect. The United Nations assigned the reporting name of "Max" to the series.
Yak-18 numbers have increasingly dwindled over time, beginning to close the door on the storied Soviet-era design for good. Fewer than 50 make up the flyable stable today (2014).