The Antonov An-70 (-70) is a four-engine medium-range transport aircraft, and the first aircraft to take flight powered only by propfan engines. It was developed in the late 1980s by the Antonov Design Bureau to replace the obsolete An-12 military transport aircraft. The maiden flight of the first prototype took place in December 1994 in Kyiv, now independent Ukraine. Within months the prototype had suffered a mid-air collision. A second airframe was produced to allow the flight-test programme to proceed. Both prototypes were produced by the Kyiv Aircraft Production Plant.

Following the dissolution of the Soviet Union in the early 1990s, the programme became a joint development between Russia and Ukraine. The former compounded the issue of a reduced market with its intermittent commitment to the project. Repeated attempts to start production have had limited success. Western European countries, including Germany, at one stage assessed the aircraft for procurement, but many later decided against it.

Development

Origins and early testing history

The origins of the An-70 can be traced back to the mid-1970s, when the Antonov Design Bureau began preliminary design work on a successor for the An-12 four-engine turboprop aircraft. The Soviet Armed Forces, by the 1980s, were looking for a replacement for the An-12 and a complement to the Ilyushin Il-76 four-engine jet transporter; in 1987, the Ministry of Defence, with a new emphasis on air mobility, specified an aircraft with a quick loading time, the ability to operate from short unprepared airfields, could carry up to 300 troops, and have good operating economy. The following year, twenty companies and organisations from the former Soviet Union agreed to jointly develop, market and support the aircraft. and workers' salaries. In addition, engineers discovered numerous design and manufacturing deficiencies during the final ground checks, the majority of which were non-critical yet necessitated lengthy corrections. In the end, the aircraft made its maiden flight on 16 December 1994.

thumb|The first An-70 prototype in November 1994

Crewed by a seven-man team, the first aircraft performed a short take off from Svyatoshino Airfield, Kyiv. This was the first flight of an aircraft that was powered only by propfans. Due to worsening weather conditions over Antonov's headquarters and the flight test area in Kyiv, the flight was cut short, and the flight ceiling was capped at . The crew took the aircraft to a height of , while performing basic checkouts of the prototype's systems. After having been airborne for less than half an hour, the aircraft landed at Antonov's flight test facility at Hostomel. During the flight, engineers identified problems with the engine gearboxes, and so the aircraft was grounded for eight weeks while the issues were fixed. Although there were initial allegations of technical issues with the aircraft, it was later determined that the crash had been caused by human error.

Antonov subsequently converted the static-test prototype into a flying prototype equipped with a modified flight-control system. The second airframe was rolled out in December 1996 in Kyiv, before making its first flight on 24 April 1997 from Svyatoshino Airfield, during which the aircraft was airborne for 31 minutes; according to Jane's, however, the aircraft had taken off from Hostomel for a 26-minute flight. The second prototype's initial flight nearly ended in disaster, as the flight-control system repeatedly malfunctioned. Test pilot Oleksandr Halunenko was forced to manually land the prototype, for which he was honored with the Hero of Ukraine title. By this time, more than US$2.5 billion had been spent on the programme, with a further $200 million to be spent to prepare the aircraft for production, which was expected to have started in 1999 with 20–25 aircraft produced annually. The Russian and Ukrainian Air Forces reportedly had long-term plans to procure 500 and 100 aircraft, respectively. The second airframe was severely damaged during cold weather testing on 27 January 2001 in a crash landing after take-off. 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 the responsibility of evaluating the An-70 and assessing whether it would fulfill the ESR for a common tactical airlifter. Airbus provided data of the aircraft to DASA, who confirmed the data with its own wind-tunnel tests. 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 full authority digital engine control, a completely new cockpit, a new flight-control system computer, the addition of in-flight refuelling capability, as well as modifications to allow paratroopers to be dropped from the rear cargo door. DASA recommended a change in the manufacturing method of the carbon-fiber-reinforced polymer components. Also the fuselage manufacturing-method was considered uneconomical. German, Ukrainian and Russian companies had formed the joint-venture "AirTruck" to plan and manage the modifications needed to westernise the An-70.

The German government, for political reasons, preferred the An-70. During a separate German Ministry of Defence evaluation of the An-7X, the aircraft was apparently considered to be superior to the A400M designed by the military branch of Airbus. According to AirTruck, the Defence Ministry estimated the An-7X to be 30 percent cheaper than its rival, would provide industrial benefits as Germany would receive substantial workshare, and was deemed to be technically superior, due mainly to its new propfan technology; however, a Defence Ministry spokesperson denied that a conclusion had been reached. On the other hand, DASA preferred the A400M, and refused to be the prime contractor for the An-70 if it was to be chosen. In the meantime, Belgium, France, Italy, Portugal, Spain, Turkey and the UK, were tentative members of the FLA programme and were estimated to have a requirement for up to 288 aircraft; Russia and Ukraine themselves were looking to acquire 210 An-70s. Other contenders for the FLA were the C-17 and C-130J. In April 2000, the German government, the strongest supporter of the An-70, stated that it was committed to buying the same aircraft as the other countries. In the end, the A400M was chosen for the FLA project; had the An-70 been chosen, fifty percent of the aircraft would have been manufactured by Airbus.

2001 incident and later disputes

In December 1999, the Russian government outlined that it planned to purchase 164 aircraft by 2018. The Ukrainian government in October 2000 estimated that the country had a requirement for 65 aircraft. By then, the Russian government had awarded the Polyot plant, which was based in Omsk, the right to produce the aircraft, ahead of Aviakor and Aviastar of Samara and Ulyanovsk, respectively. The Kyiv Aircraft Production Plant was expected to produce the first aircraft in 2003, and Polyot, in 2004. As the An-70 flight test programme had reached its final stages by the end of 2000, it was expected that the Russian and Ukraine Defence Ministries would approve of mass production at the start of 2001. On 27 January 2001, however, the second An-70 prototype made a crash landing on its belly after losing power in two engines on take-off during cold weather testing in Omsk, and was severely damaged. Four of the 33 people on board were injured. Antonov recovered the crashed aircraft and repaired it, but the project still lacked funding.

thumb|An-70 in-flight

In January 2002, preparations started on mass production as the Russian government affirmed that the aircraft was in the country's nine-year military budget; by now, Ukraine had already placed an order for five aircraft.

Nevertheless, Antonov looked elsewhere for an industrial partner. In September that year, the company signed a memorandum of understanding (MoU) with China Aviation Industry Corporation II that covered the possible joint development of transport aircraft. Russian ambivalence towards the An-70 was made evident when the Russian Defence Ministry did not allocate any funds in the near future towards the procurement of the aircraft for its air force. Instead, resources were dedicated towards the upgraded Il-76MF. In April 2006, General Mikhaylov announced that Russia was withdrawing from the project, although at the time there was no official confirmation from the Russian government itself. Mikhaylov had reportedly been a staunch opponent of the An-70, claiming that the D-27 engine was "unreliable", and had advocated for the adoption of the Il-76MF, which was estimated to cost half that of the An-70. Up until then, Russia had provided around 60 percent of the estimated $5 billion invested in the project. According to various reports, Russia's conflict with Georgia in August 2008 highlighted the need for an airlifter in the class of the An-70, one that had a spacious cargo bay and the ability to operate from unpaved airstrips. Consequently, in August 2009, both countries agreed to resume development of the An-70. Ukraine continued to pursue flight testing of the sole prototype while making upgrades to the aircraft's avionics, sensors and propulsion system. It was reported that the Ukrainian Air Force would take delivery of its first two An-70s in 2011 and 2012; Volga-Dnepr Airlines had also signed an MoU with Antonov for five commercial-standard An-70Ts. A requirement for 60 An-70s was included in Russia's 2011–2020 national armament programme when it was issued in December 2010. During the same year, Russian and Ukrainian authorities agreed on the basic workshare of the production programme. Antonov in Kyiv would now produce the wings, tail surfaces and engine nacelles. The KAPO factory in Kazan, Russia, would be responsible for the manufacture of the fuselage, the final assembly of the aircraft, and flight testing. Other major components would come from Novosibirsk, Ulyanovsk and Voronezh;

The test programme would last from September 2012 until April 2014, when the aircraft passed state acceptance trials. During that time, the An-70 conducted approximately 120 flights totalling 220 hours, with much of the certification effort carried out by Ukrainian specialists and officials. This is because, despite the aircraft's inclusion in Russia's state rearmament programme, Russia had withdrawn from the project in November 2012 reportedly due to slow progress, a fact that was disclosed only in April 2013. According to a report, the withdrawal of Russia from the project was—apart from a response to the Ukrainian government's EU choices—the result of political manoeuvring by Russian government officials with links to Ilyushin to pressure the government to purchase the Il-476, a re-winged variant of the Il-76. In total, the An-70 had conducted some 735 flights and had accumulated 930 hours during state tests.

As a result of the Russian invasion of Crimea, the Ukrainian government, in April 2014, announced that it would halt all military-technical cooperation with Russia. In August 2014, a Ukrainian court ordered the Russian Defence Ministry to make outstanding payments to Antonov. In March 2015, Russia Defence Ministry declared that it is ruling out the An-70 for state procurement. It also declared that, as in their opinion, Ukraine has withdrawn from the military and defence agreements signed before the crisis between them by completing the aircraft without Russian involvement, it would request return of 2.95 billion rubles that Russian government had spent on An-70 project.

Design

The An-70 is a monoplane with a high-mounted wing design that features four distinctive propfan engines. Designed by the Progress Design Bureau, each of the D-27 engines is rated at 13,800 shp (which can be uprated to 16,000 shp), which is used to drive the SV-27 contra-rotating scimitar propellers designed by Aerosila; eight on the front propeller and six on the aft propeller. The propfan engines deliver slipstream to the supercritical wings that feature double-slotted flaps on its trailing edges to provide high lift coefficients at low speeds. According to DASA's evaluation, the propfan engines were 10 percent more efficient than conventional turboprops. In exceptional circumstances, the An-70 subjected to lower-g take-offs, can airlift a T-80U main battle tank and fly it for .

;An-112KC: A proposed aerial refueling version of the An-70, except with two jet engines from the team of U.S. Aerospace and Antonov for the U.S. Air Force's KC-X program. The USAF rejected the proposal, and the appeal was later dismissed.

;An-170: A heavy-lift version with a stretched fuselage and greater wing span. The aircraft would be powered by the Progress D-227, a more powerful derivative of the Progress D-27 producing of output.

;An-171: Proposed maritime patrol version of An-170.

;An-188:

thumb|right|Proposed An-188 variant

A program to develop this variant was launched at the 2015 Paris Air Show. This variant will essentially be a four jet engine powered heavy-medium transport with modernized NATO- compatible western cockpit, slightly enlarged wings, winglets and aerial refueling capabilities. The An-188 is intended to fill the gap between a C-130 and C-17 while being a direct competitor to the A400M. Plans include incorporating a western engine option along with the D-27 to appeal to western markets and reduce dependency on eastern markets. In May 2018, Ukroboronprom announced at the Eurasia-2018 Airshow held in Turkey's Antalya, that Ukraine and Turkey had agreed to jointly implement the production of the aircraft.

Operators

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  • Ukrainian Air Force – In 2010, two deliveries were expected in 2011 and 2012. Satellite imagery in 2024 revealed that one An-70 aircraft was parked near the Polish Air Force Academy in Dęblin, Poland, away from the conflict zone created by the 2022 Russian invasion of Ukraine.

Specifications (An-70)

See also

References

  • Antonov product page