Lotarev DV-2
The Lotarev DV-2 (or PSLM DV-2, DV: Dnepr-Váh) is a two-spool turbofan engine manufactured in Považská Bystrica, Slovakia by Považské Strojárne Letecké Motory (PS Aircraft Engines/Motors) (PSLM) (former ZVL Závody na Výrobu Ložísk "Bearings Production/Manufacturing Plant") and designed in partnership with Ivchenko Lotarev Design Bureau. Design and development. Developed from the Ivchenko AI-25 turbofan engine, ZVL was also responsible for pre-production and serial engine production. The DV-2 is a two-spool modular aviation turbofan engine with a single-stage overhung fan, two-stage LP compressor, seven-stage HP compressor, single-stage HP turbine , and two-stage LP turbine, and an annular combustion system. Maximum power at T-O is with a specific fuel consumption of 60 kg/(kN h) (0.593 (lb/lbf h)), at Maximum Rating, Sea Level Static, ISA. One of the most unusual features of this military engine is the single stage fan; most trainer and combat engines have multi-staged fans, single stage fans normally being the preserve of civil and military transport turbofans. Ivchenko Lotarev chose a very low specific thrust (net thrust/airflow) cycle for the DV-2, so a single stage fan is sufficient to develop the desired fan  pressure ratio. Even so, the pressure ratio produced is somewhat higher than that normally developed by a single stage fan. Owing to the low specific thrust, the bypass ratio for the engine is higher than normal for a military turbofan. This engine was required to power new versions of the L-39 trainer, L-39MS and L-59. Other turbofan engine models in the DV-2 family include the DV-2A, DV‑2A.2 and DV-2S. The DV-2S was renamed "RD-35" by the Klimov under license agreement with the PSLM in 1993.