D-20P

First Russian Turbofan Aviation Engine

By the end of the 40s of the past century, the potential of the piston-type engines was fully exhausted. After the Second World War, practically all the engine designing companies were actively involved with the aviation gas turbine engines development. Perm designers focused on that task in 1953, when Pavel Solovyov headed Experimental and Design Bureau No. 19.

The Perm Design Bureau performed great amount of work on studying different schemes of air-breathing engines, and chose the advanced turbofan engine which provided for the fuel savings at all the engine modes and especially at high subsonic flying speeds. The idea of the turbofan engine had been earlier proposed by prominent Soviet aviation engine designer A.M. Lyulka.

In 1956, the development of twin-spool augmented turbofan engine D-20 started. The plan was to install the engine on A.N. Tupolev’s bomber. Five prototype engines were produced; however, the aircraft project was abandoned.

In 1960, the first serial turbofan two-shaft D-20P (P for “passenger”) was developed on the basis of the D-20 twin-spool augmented turbofan engine. The successful state tests of the engine confirmed its bypass scheme as a principal scheme in the domestic aviation engine building.

Setting up the D-20P production at Y.M. Sverdlov serial plant (now UEC-PM) was not easy. Even qualified assemblers could not quickly catch all the technical specifics of the new engine. It was necessary to quickly solve all the discovered issues associated with manufacturing and testing of the engines. For this, the first leading brigade on supervising the D-20P serial manufacturing was created in 1961. It helped to solve such defects as engine vibration, sparking at the nozzle labyrinth contact with the turbine disks, resonance oscillations of the LPC 1 stage blades and others.

The D-20P engine became the first domestic serial turbofan two-shaft engine. 1795 engines D-20P were manufactured in total.

The D-20P engine with 5 400 kgf thrust was widely used as part of the propulsion unit of the first domestic short-haul passenger aircraft Tu-124 developed by Andrey Tupolev’s Design Bureau.

In 1961, augmented turbojet one-shaft engine D-21 was developed on the basis of D-20P. The new engine was meant for powering the all-weather strategic spy, which was the first airplane in the world capable of air observation at supersonic speed and at 1700 km distance away from the home aerodrome. Although the plane was developed by Experimental Design Bureau No. 256 headed by P. V. Tsybin, it shared the same destiny with the engine and was not produced in series.