The United Aircraft Corporation (OAK) presented four rare passenger projects of the Yakovlev Design Bureau that were never realized in metal.
Yak-33 — a project for a supersonic VTOL aircraft, developed in the early 1960s. The maximum estimated speed reached Mach 3, and the flight range was up to 4000 km. It was planned to install two RD36-41 cruise engines and six lift engines. The aircraft was optimized for low-altitude flights, and steel and titanium were planned for its construction. The project was deemed too small for the tasks set and was closed.
Yak-46 — a project for a 78-seat turbofan aircraft for local airlines, developed in 1982 based on the Yak-42. The cruising speed was 700 km/h, and the normal range was 800 km. D-36 engines were located on the sides of the fuselage's tail section. The project was closed in 1982 after the Yak-42 crash, which temporarily halted the operation of all aircraft of this type.
Yak-242 — a project for a medium-haul airliner, developed in 1993 as a deep modernization of the Yak-42. The aircraft was supposed to accommodate 156–162 passengers and be equipped with two PS-90A12 engines. The design solutions of the Yak-242 formed the basis of the modern MC-21, although the name "Yak-242" was abandoned at the production stage.
Yak-48 — a project for a light administrative and regional passenger aircraft. The Russian Government Decree on its creation was issued in February 1995. The aircraft was to be equipped with two RD-35M engines. The administrative version for 4 passengers was designed for a range of up to 5000 km at a cruising speed of 870 km/h, and the 19-seat passenger version for 3310 km. In the 1990s, joint work was carried out with Israel Aircraft Industries, but due to lack of funds, development was discontinued.