The NK-93 engine was developed beginning in the late 1980s, although the design of the engine was allegedly envisioned as early as 1968. Many of the design features were adopted from the
Kuznetsov NK-92, the military complement to the NK-93. The core of the NK-93 was to form the foundation of a family of direct-drive turbofans and
geared propfans, ranging from in
thrust. It was the last major project of
Kuznetsov Design Bureau founder
Nikolai Dmitriyevich Kuznetsov. The NK-93 was originally scheduled for
flight testing in late 1993/early 1994 and certification in 1997 so that it could be used on the
Ilyushin Il-96M and
Tupolev Tu-204M. By May 1994, seven full-size versions of the engine had been built, with five of them close to the production configuration. Due to the
breakup of the Soviet Union, though, the schedule was repeatedly delayed because of severe funding shortages and other issues. However, by October 2001, a tenth NK-93 engine neared completion, out of a total of 15 planned engine prototypes. The engine finally underwent flight testing on an
Ilyushin Il-76LL
testbed aircraft beginning on December 29, 2006, with a second flight occurring on May 3, 2007. A total of 50 flight test hours were planned. Testing was suspended again in June 2007 because of funding troubles. Airborne testing did not restart until October 2008, with flights on October 2 and 6. Another test flight occurred on December 15, 2008, but the NK-93 was removed from the testbed by May 14, 2009. Supporters of the NK-93 claim that the amount of money needed to certify the engine is minuscule compared to the development costs of competing new Russian engines, which they regard as still inferior to the older NK-93. In April 2014, Kuznetsov announced that it would resume work on the NK-93 engine.
Foreign interest The advanced nature of the engine attracted the attention of airframers and engine manufacturers in other countries. By 1992, the NK-93 was already drawing interest from the Japanese aviation industry. Investors from South Korea were among the groups discussing investment in the NK-93 at the 2001
MAKS air show. In 2004,
Airbus and the Kuznetsov Design Bureau studied the feasibility of using the engine to power Airbus commercial aircraft. German engine maker
MTU Aero Engines purchased a Kuznetsov report on the noise characteristics of the NK-93 engine for 600,000
Deutsche marks. When the NK-93 was displayed on the Il-76LL demonstrator at the 2007 MAKS air show, Chinese aircraft manufacturers reportedly made a "tempting offer" to buy all of the NK-93's blueprints and documentation. In October 2013, the European Commission gave a three-and-a-half-year grant to study the
Innovative Counter rOtating fan system for high Bypass Ratio Aircraft engine (COBRA). COBRA was a European Union-Russia cooperative program to study an ultra-high
bypass ratio (UHBR) counter-rotating turbofan (CRTF) that was similar to the NK-93. Participating organizations included Kuznetsov, CIAM, Russian propeller manufacturer
Aerosila, French engine maker
Safran (Snecma), the French aerospace laboratory (
ONERA), and the
German Aerospace Center (DLR). ==Design==