Progress D-27

Ivchenko Progress

Company type	Design bureau
Industry	Aerospace engineering
Founded	1985
Headquarters	Zaporizhzhia , Ukraine
Area served	Aerospace industry
Products	Aircraft engines (including Progress D-27)

Template:Infobox aero engine

The Progress D-27 is a three-shaft propfan engine developed by Ivchenko Progress and manufactured in Ukraine by Motor Sich. Its gas generator design draws from experience gained with the Lotarev D-36 turbofan. The D-27 was initially created to power fuel-efficient passenger aircraft, including the cancelled Yakovlev Yak-46 project, and was ultimately selected for the Antonov An-70 military transport plane. As of 2019, it remains the sole contra-rotating propfan engine to have entered operational service.

Design and development

The project began in 1985 at the Ivchenko-Progress Design Bureau targeting both commercial and military transport applications. The engine was engineered to address anticipated increases in demand for new aero engines across civil and defense sectors. It delivers a takeoff power rating of 13,240 horsepower (9,870 kW) tailored for the Antonov An-70. Other sources cite power ratings ranging from 13,880 to 16,250 hp (10,350 to 12,120 kW).

By 1990, the D-27 was proposed as the propulsion system for the 150–162 seat Yakovlev Yak-46, a twin-engine derivative of the three-engine Yakovlev Yak-42. This configuration placed two D-27 engines on the rear fuselage. At that time, its fan diameter measured approximately 3.8 metres (12 ft), generating around 9,700 kW (13,000 hp) at takeoff, which translated to a thrust of about 11,200 kilograms-force (110,000 N; 25,000 lbf). The engine achieved a thrust specific fuel consumption (TSFC) of roughly 0.47 at a cruise speed near 850 km/h (530 mph).

File:Il-76LL.jpg

The Progress D-27 installed on an Ilyushin Il-76LL flying testbed during the 1997 MAKS air show.

A single D-27 prototype was flight-tested on an Ilyushin Il-76 modified as a testbed aircraft from at least 1992, in preparation for integration into the Antonov An-70T military transport. The variant for the An-70T produced approximately 10,290 kW (13,800 hp) and featured propellers with a diameter of about 4.5 m (15 ft). In 1993, this Il-76LL with D-27 engines was displayed statically at Moscow’s MAKS Air Show and subsequently flew at both the 1994 ILA Berlin Air Show and Farnborough Air Show. The testbed made its final MAKS appearance in 1997.

On December 16, 1994, four D-27 engines powered the maiden flight of the first An-70 prototype, marking the inaugural aircraft flight powered exclusively by propfan engines. Unfortunately, during its fourth flight in February 1995, this prototype crashed, resulting in total loss and no survivors. Antonov then built a second prototype, which successfully completed its first flight on April 24, 1997, equipped with four new D-27 engines. This aircraft also participated in the 1997 MAKS Air Show and the 1998 ILA Berlin Air Show during testing.

The D-27 features a three-shaft gas turbine design incorporating an axial low-pressure compressor, a mixed-flow high-pressure compressor, an annular combustion chamber, along with single-stage high-pressure and low-pressure turbines. The SV-27 contra-rotating propfan—supplied by SPE Aerosila—is driven through a four-stage turbine connected via a shaft to a planetary reduction gearbox that includes a thrust meter. The front propeller has eight blades and delivers most of the engine’s power output and thrust, while the rear propeller has six blades. Propeller rotational speeds reach approximately 1,000 rpm at takeoff and reduce to about 850 rpm during cruise. The engine achieves an overall thermal efficiency near 37 percent.

On December 23, 2005, Antonov announced that the An-70 variant powered by D-27 engines received certification confirming compliance with Stage 3 noise standards, enabling unrestricted international airline operations. In response to US Stage 4 noise regulations introduced in 2006, modifications were made in 2007 to increase spacing between front and rear propellers to reduce noise emissions further. Additional adjustments between 2010 and 2012 further increased propeller separation by approximately 50%, from 600 to 900 millimeters.

The Ukrainian military formally inducted the An-70 equipped with D-27 engines into service on January 19, 2015.

On September 3, 2019, Russia’s navy announced plans to procure Beriev A-42 amphibious aircraft—which had been under development since suspension in 1993—with expectations these would be powered by two D-27 propfans each. The initial order was for three units; however, no specific delivery schedule was provided. Despite this, Motor Sich’s engine manufacturing facility located in Zaporizhzhia was destroyed by Russian forces in late May 2022 amid the 2022 Russian invasion of Ukraine.

Variants

File:Antonov AN-70 at Paris Air Show 2013 5.jpg

A frontal perspective showing two Progress D-27 engines mounted on the starboard wing of an Antonov An-70 during the 2013 Paris Air Show.

Between 1988 and 1995, Ivchenko-Progress focused on developing several derivatives derived from the D-27 engine core. The proposed variants included:

D-27A

a 14,000 hp (10,000 kW) engine variant intended for the Beriev A-42PE jet-powered amphibious search and rescue (SAR) aircraft, which was proposed in 1994.

D-27M

an enhanced version delivering 16,000 hp (12,000 kW).

D-127

a turboshaft engine rated at 14,500 hp (10,800 kW), designed to power the Mil Mi-26M heavy-lift helicopter, with production planned for 1998.

AI-127

a helicopter powerplant producing 14,500 hp (10,800 kW), developed from the D-27 core. This engine features a power-specific fuel consumption (SFC) of 0.181 kg/(hp⋅h) (0.243 kg/kWh; 0.40 lb/(hp⋅h)) at takeoff and 0.210 kg/(hp⋅h) (0.282 kg/kWh; 0.46 lb/(hp⋅h)) in cruise conditions.

D-227

an unducted propfan that could operate either as gearless (direct-drive) or with gearing, delivering between 16,000 to 17,000 hp (12,000 to 13,000 kW). This variant was intended for the Antonov An-170, a derivative of the An-70, and was also proposed for use on the Tupolev Tu-334.

File:Antonov AN-70 at Paris Air Show 2013 7.jpg

Rear view of two Progress D-27 propfans showing six-blade aft propellers and eight-blade forward propellers.

D-527

featuring an exceptionally high bypass ratio of 18, this ducted engine was considered for the Tupolev Tu-334. Nicknamed "super contrafan," it incorporated direct-drive contra-rotating fans located at the rear, similar to Rolls-Royce's conceptual RB529 "Contrafan".

D-627

a super-high bypass turbofan capable of producing up to 11,000 kgf (24,000 lbf; 110 kN) thrust at takeoff. Designed as an alternative engine for the Yakovlev Yak-46, it aimed for a specific fuel consumption not exceeding 14 g/(kN⋅s) (0.5 lb/(lbf⋅h)) at cruising altitude of 11,000 m (36,000 ft) and speed of Mach 0.8 (461 kn; 854 km/h; 531 mph). The design incorporated coaxial contra-rotating fans driven via a differential gearbox.

D-727

developed for the commercial An-70 variant known as An-70T, this high-bypass turbofan has a bypass ratio of 12.85. It also served as the propulsion system for the Yakovlev Yak-46-1, which is a high-bypass turbofan iteration of the Yakovlev Yak-46.

AI-727

a family of ultra-high bypass ratio geared turbofan engines with nearly 13 bypass ratio, featuring low-noise wide-chord fans and thrust ranging from 10,000 to 11,500 kilograms-force (22,000 to 25,000 lbf; 98 to 113 kN). The engine’s takeoff thrust specific fuel consumption (TSFC) is 7.3 g/(kN⋅s) (0.257 lb/(lbf⋅h)), while cruise TSFC stands at 15.3 g/(kN⋅s) (0.540 lb/(lbf⋅h)). It was proposed as a powerplant option for both the Antonov An-148T and the Irkut MS-21.

Applications

File:Antonov AN-70 at Paris Air Show 2013 4.jpg

Side perspective of the D-27 propfan installed on the Antonov An-70 during the 2013 Paris Air Show.

• Antonov An-70
• Antonov An-180 (project discontinued)
• Beriev A-42
• Ilyushin Il-76 (used as a test platform)
• Tupolev Tu-334 (not adopted)
• Tupolev Tu-95MS (planned re-engining)
• Yakovlev Yak-44 (development ceased)
• Yakovlev Yak-46 (development ceased)

External links

• D-27 propfan at Ivchenko-Progress (archived April 7, 2019)
• D-27 on Motor Sich JSC website (archived October 24, 2018)
• High-resolution image of the D-27 engine provided by Motor Sich
• Beriev - A-42PE amphibious aircraft on Beriev Aircraft Company site (archived October 7, 2003)