The Antonov An-70 is a four-engine medium-range transport aircraft, and the first large aircraft to be powered by propfan engines. It has been developed in late 80th in Antonov design bureau to replace the obsolete An-12 military transport aircraft. Unfortunately the dissolution of the Soviet Union prevented the mass production of the type. Maiden flight of the first prototype took place on 16 December 1994 in Kiev, now independent Ukraine, and the plane was lost in less than a year. Numerous further attempts to start production haven't been so far successful.
The An-70 is a high-wing monoplane with four wing-mounted propfan engines, it has a full glass cockpit and fly-by-wire controls. The aircraft has a 19.1 metre (22.4 metre with the ramp) x 4 metre x 4.1 metre cargo space and can carry 47 ton of cargo, or approximately 300 troops or 200 injured personnel. Powered by four Progress D-27 propfan engines, each turning a pair of contra-rotating scimitar propellers.
The An-70 was the first Eastern-bloc transport aircraft to be built according to the new IAC AP-25 norms that conformed with JAR-25. This would allow civilian certification in both Western Europe and North America. Another first was the use of a MIL-STD-1553B-compatible data bus, which allows NATO avionics and defensive suites to be installed.
Early development and testing history
There were plans to establish serial production of the model in both Kiev and Samara, Russia, guaranteeing employment of about 80,000 people in the two countries. The initial contract to build the An-70 was concluded in May 1989. The Soviet government had shown interest in purchasing 160 planes for its military. But in the post-Soviet days of reduced military budgets in Russia, funding for the An-70 was cut. Antonov decided to proceed with self-funding.
Development of the Ukrainian military aircraft
The development of An-70 began in the 1990s and the first prototype was rolled out in January 1994. The maiden flight of the first prototype occurred in December 1994 in Kiev, Ukraine. It crashed in February 1995 during a mid-air collision that took place with an An-72 chase plane.
Antonov launched the second prototype in December 1996 and its maiden flight took place in April 1997. The prototype was showcased at the Moscow Air Show in August 1997. The second prototype also endured damage in January 2001 due to an emergency landing.
Russia and Ukraine unveiled a decision in June 2000 to build a Chinese An-70 version with co-operation from China. The two nations jointly financed the development of An-70 in 2002 as part of a 50:50 risk sharing deal. The Chinese version was displayed at MAKS Air Show held in Russia in 2003. Russia, however, withdrew from the project in April 2006, due to financial crisis and rigid political relationships between Russia and Ukraine. China and Ukraine jointly built the An-70-600 in 2008.
In August 2009, Russia signed a deal with Ukraine to renew its plans to fund the An-70 project. Russia offered $11m in December 2009 and is planning to invest an additional $96m. The user testing of the aircraft took place in August 2010. Antonov transferred the design documentation to Russia for commencing the production at Kazan aviation plant.
An-7X and Future Large Aircraft (FLA)
The An-70 was first considered in the early 1990s as an FLA-platform but was then rejected. In October 1997, the German defense minister Volker Rühe announced his intention to study whether the An-70 could be the basis for the Future Large Aircraft (FLA). Rühe wanted to use the An-70 based programme as example of the German foreign policy in Eastern Europe. The German Government was searching for routes to provide industrial aid to Eastern Europe. In December 1997, France, Germany, Russia and Ukraine agreed to evaluate the An-70 as a candidate for the FLA programme.
Antonov proposed a "westernised" version of the An-70, the An-7X. The German government tasked DaimlerChrysler Aerospace (DASA) with a study, the purpose of which was to evaluate the An-70 and assess if it would fulfil the European Staff Requirement for a common tactical airlifter. DASA depended on data provided by Antonov and was not able to test-fly the aircraft themselves. However they conducted wind-tunnel tests and the results confirmed the data. According to the DASA study from 1999 the An-70 fulfilled the ESR, and that westernisation is possible, but work in key areas would have been necessary and risks existed. Areas identified include the introduction of a full-authority digital engine control, integrated engine monitoring system, prop synchronising system, completely new cockpit, new flight control system computer, replacement of CIS military equipment, replacement of the digital flap/slat-system computer, fuel-jettison system and in-flight refuelling capability, a possible lengthening of the axles of the landing gear, a new digitally controlled braking and steering, new wires for the electrical system, the auxiliary power unit, the cargo-handling system and the loadmaster station. DASA recommended a change in the manufacturing method of the CFRP-components. Also the fuselage manufacturing-method was considered uneconomical. They were not able to assess the manufacturing of the wing because no data was available. DASA stated that the manufacture meets ISO 9000 quality standards but the East-West processes and procedures have to be harmonised. German, Ukrainian and Russian companies had formed the joint-venture “Airtruck” to plan and manage the modifications needed to westernise the An-70. German Companies in Airtruck included DASA Aircraft Services Lemwerder, Autoflug, BMW, Rolls-Royce and Liebherr Aerospace.
The German government, for political reasons, preferred the An-70-based solution, while the industry, DASA, preferred the A400M from the military branch of Airbus. In the meantime France, Italy and Spain have also shown interest in the An-70. Other contenders for the FLA were the Boeing C-17 and Lockheed Martin C-130J. Had the An-70 been chosen, fifty percent of the aircraft would have been manufactured by Airbus; in the end, the A400M was chosen for the FLA project.
Antonov An-70 design and cockpit
The An-70 was designed to take-off from and land on concrete and unpaved airstrips including soft ground and snow. It can manoeuvre day or night in bad weather conditions.
The airframe is constructed with composite materials to reduce the overall weight of the aircraft by 20% to 30%.
The aircraft boasts a large freight compartment for cargo storage. The compartment is 19.1m long, four metres wide and 4.1m high. It can accommodate 35,000kg to 47,000kg of cargo and 300 troops. It can also carry 38,000kg of fuel.
The An-70 features a spacious glass cockpit which can accommodate the three crew members - pilot, co-pilot and flight engineer. The cockpit is fitted with six full colour digital displays and a head up display, which aids the aircraft's landing on short airfields.
Automated navigational and flight control systems are incorporated for quick analysis and servicing.
Engines and cargo systems of the military freighter aircraft
The Antonov An-70 is powered by four Ivchenko Progress D-27 three-shaft propfan engines. Each engine can produce 10,350kW of output power. FADEC compatible, the D-27 engine is fitted with two remote gearboxes, a single stage compressor, a four stage low pressure turbine and a jetpipe.
The engine is 4.19m long, 1.25m wide and 1.37m high. Its dry weight is 1,650kg. The lifespan of the engine is 18,000 hours.
The incorporation of SV-27 counter rotating propeller in the power plant increases cruise speed as well as reduces the fuel consumption by 20% to 30% as compared to modern turbojets.
The aircraft features four overhead rail electric motor hoists to lift 12,000kg of cargo. Two on-board electric winches can lift 30,000kg of freight. A built-in aerial delivery system allows autonomous loading or unloading of cargoes and can be used for air drops.
Antonov An-70 performance
The An-70 can climb at a rate of 24.9m/s. The maximum and cruise speeds of the aircraft are 780km/h and 750km/h respectively.
The stall speed is 113km/h. The range of the aircraft is 6,600km, while the ferry range is 8,000km. The service ceiling is 12,000m.
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