Soviet/Ukrainian heavy strategic cargo aircraft
The Antonov An-225 Mriya (; NATO reporting name: Cossack) was a strategic airlift cargo aircraft designed and produced by the Antonov Design Bureau in the Soviet Union.
It was originally developed during the 1980s as an enlarged derivative of the Antonov An-124 airlifter for transporting "Buran" spacecraft. On 21 December 1988, the An-225 performed its maiden flight; only one aircraft was ever completed, although a second airframe with a slightly different configuration was partially built. After a brief period of use in the Soviet space programme, the aircraft was mothballed during the early 1990s. Towards the turn of the century, it was decided to refurbish the An-225 and reintroduce it for commercial operations, carrying oversized payloads for the operator Antonov Airlines. Multiple announcements were made regarding the potential completion of the second airframe, though its construction largely remained on hold due to a lack of funding. By 2009, it had reportedly been brought up to 60–70% completion.
With a maximum takeoff weight of , the An-225 held several records, including heaviest aircraft ever built and largest wingspan of any operational aircraft. It was commonly used to transport objects once thought impossible to move by air, such as 130-ton generators, wind turbine blades, and diesel locomotives. Additionally, both Chinese and Russian officials had announced separate plans to adapt the An-225 for use in their respective space programmes. The Mriya routinely attracted a high degree of public interest, attaining a global following due to its size and its uniqueness. 
The only completed An-225 was destroyed in the Battle of Antonov Airport in 2022 during the Russian invasion of Ukraine. Ukrainian president Volodymyr Zelenskyy announced plans to complete the second An-225 to replace the destroyed aircraft.
Development.
Work on the Antonov An-225 began in 1984 with a request from the Soviet government for a large airlifter as a replacement for the Myasishchev VM-T. The specifics of this request included the ability to carry a maximum payload of , both externally and internally, while operating from any runway of at least . As originally set out, the mission and objectives were broadly identical to that of the United States' Shuttle Carrier Aircraft, having been designed to airlift the Energia rocket's boosters and the "Buran"-class orbiters for the Soviet space program. Furthermore, a relatively short timetable for the delivery of the completed aircraft meant that development would have to proceed at a rapid pace.
Accordingly, the Antonov Design Bureau produced a derivative of their existing Antonov An-124 Ruslan airlifter. The aircraft was stretched via the addition of fore and aft fuselage barrel sections, while a new enlarged wing centre was designed that facilitated the carriage of an additional pair of Progress D-18T turbofan engines, increasing the total from four to six powerplants. A completely new tail was also required to handle the wake turbulence generated by the bulky external loads that would be carried on the aircraft's upper fuselage. Despite the novelty of its scale, the design of the An-225 was largely conventional. The lead designer of the An-225 (and the An-124) was Viktor Tolmachev.
On 21 December 1988, the An-225 performed its maiden flight. It made its first public appearance outside the Soviet Union at the 1989 Paris Air Show where it was presented carrying a Buran orbiter. One year later, it performed a flying display for the public days at the Farnborough Air Show. While two aircraft had been ordered, only a single An-225, (registration "CCCP-82060", later "UR-82060") was finished. It could carry ultra-heavy and oversized freight weighing up to internally or on the upper fuselage. Cargo on the upper fuselage can be up to in length.
A second An-225 was partially built during the late 1980s for the Soviet space program, however, work on the airframe was suspended following the collapse of the Soviet Union. By 2000, the need for additional An-225 capacity had become apparent; during September 2006, it was decided that the second An-225 would be completed, a feat that was at one point scheduled to occur around 2008. However, the work was subject to repeated delays. By August 2009, the aircraft had not been completed and work had been abandoned. In May 2011, the Antonov CEO reportedly stated that the completion of the second An-225, which would have a carrying capacity of 250 tons, requires at least $300 million; upon the provision of sufficient financing, its completion could be achieved in three years. According to different sources, the second aircraft was 60–70% complete by 2016.
The revival of space activities involving the An-225 was repeatedly announced and speculated upon throughout its life. During the early 2000s, studies were conducted into the production of an even larger An-225 derivative, the eight-engined Antonov An-325, which was intended to be used in conjunction with Russia's in-development MAKS space plane. In April 2013, the Russian government announced plans to revive Soviet-era air launch projects that would use a purpose-built modification to the An-225 as a midair launchpad.
In May 2017, Airspace Industry Corporation of China (AICC)'s president, Zhang You-Sheng, informed a BBC reporter that AICC had first contemplated cooperation with Antonov in 2009 and made contact with them two years later. AICC intends to modernize the second unfinished An-225 and develop it into an air launch to orbit platform for commercial satellites at altitudes up to . The aviation media cast doubt on the production restart, speculating that the ongoing Russo-Ukrainian war would prevent various necessary components that would have been sourced from Russia from being delivered; it may be possible that China could manufacture them instead. That project did not move forward but UkrOboronProm, the parent company of Antonov, had continued to seek partners to finish the second airframe.
On 25 March 2020, the first An-225 commenced a series of test flights from Hostomel Airport near Kyiv, after more than a year out of service, for the installation of a domestically designed power management and control system.
Design.
The Antonov An-225 was a strategic airlift cargo aircraft that retained many similarities with the preceding An-124 airlifter that it was derived from. It had a longer fuselage and cargo deck due to the addition of fuselage barrel extensions that were fitted both fore and aft of the wings. The wings, which were anhedral, also received root extensions to increase their span. The flight control surfaces were controlled via fly-by-wire and powered by triple-redundant hydraulics. Furthermore, the empennage of the An-225 was a twin tail with an oversized, swept-back horizontal stabilizer, having been redesigned from the single vertical stabilizer of the An-124. The use of a twin tail arrangement was essential to enable the aircraft to carry its bulky external loads that would generate wake turbulence, disturbing the airflow around a conventional tail.
The An-225 was powered by a total of six Progress D-18T turbofan engines, two more than the An-124, the addition of which was facilitated by the redesigned wing root area. An increased-capacity landing gear system with 32 wheels was designed, some of which are steerable; these enable the airlifter to turn within a runway. Akin to its An-124 predecessor, the An-225 incorporated a nose gear designed to "kneel" so cargo can be more easily loaded and unloaded. Additional measures to ease loading and unloading activities included the four overhead cargo cranes that could move along the whole length of the cargo hold, each of which was capable of lifting up to . To facilitate the attachment of external loads, such as the Buran orbiter, various mounting points were present along the upper surface of the fuselage.
Unlike the An-124, the An-225 was not intended for tactical airlifting and was not designed for short-field operations. Accordingly, the An-225 does not have a rear cargo door or ramp, as are present on the An-124, these features having been eliminated in order to save weight. The cargo hold was in volume; wide, high, and long—longer than the first flight of the Wright Flyer. The cargo hold, which was pressurized and furnished with extensive soundproofing, could contain up to 80 standard-dimension cars, 16 intermodal containers, or up to of general cargo.
The flight deck of the An-225 was at the front of the upper deck, which was accessed via a ladder from the lower deck. This flight deck was largely identical to that of the An-124, save for the presence of additional controls to manage the additional pair of engines. To the rear of the flight deck was an array of compartments which, amongst other things, accommodated the crew stations for the aircraft's two flight engineers, navigator, and communication specialist, along with off-duty rest areas, including beds, which facilitated long range missions to be flown. Even when fully loaded, the An-225 was capable of flying non-stop across great distances, such as between New York and Los Angeles.
As originally constructed, the An-225 had a maximum gross weight of , however, between 2000 and 2001, the aircraft received numerous modifications at a cost of US$million, such as the addition of a reinforced floor, which increased the maximum gross weight to . Both the earlier and later takeoff weights establish the An-225 as the world's heaviest aircraft, exceeding the weight of the double-deck Airbus A380 airliner. Airbus claims to have improved upon the An-225's maximum landing weight by landing an A380 at during testing.
Operational history.
The Antonov An-225 Mriya was originally operated between 1988 and 1991 as the prime method of transporting "Buran"-class orbiters for the Soviet space program. Its first pilot was Oleksandr Halunenko, who continued flying it until 2004. "Antonov Airlines" was concurrently founded in 1989 after it was set up as a holding company by the Antonov Design Bureau as a heavy airlift shipping corporation. This company was to be based in Kyiv, Ukraine, and operate from London Luton Airport in partnership with Air Foyle HeavyLift. While operations began with a fleet of four An-124-100s and three Antonov An-12s, the need for aircraft larger than the An-124 became apparent by the late 1990s.
By this time, the Soviet Union was no longer in existence and the "Buran" program had been terminated; consequently, the sole completed An-225 was left unused and without a purpose. As early as 1990, Antonov officials were openly speaking on their ambitions for the aircraft to enter commercial use. Despite this, in 1994, it was decided to put the An-225 into long-term storage. During this time, all six of its engines were removed for use on various An-124s, while the second uncompleted An-225 airframe was also stored. As the 1990s progressed, it became clear that there was sufficient demand for a cargo liner even bigger than the An-124. Accordingly, it was decided that the first An-225 would be restored.
The aircraft was re-engined, received modifications to modernise and better adapt it to heavy cargo transport operations, and placed back in service under the management of Antonov Airlines. It became the workhorse of the Antonov Airlines fleet, transporting objects once thought impossible to move by air, such as 130-ton generators, wind turbine blades, and even diesel locomotives. It also became an asset to international relief organizations for its ability to quickly transport huge quantities of emergency supplies during multiple disaster-relief operations.
Under Antonov Airlines, the An-225 received its type certificate from the Interstate Aviation Committee Aviation Register (IAC AR) on 23 May 2001. The type's first flight in commercial service departed from Stuttgart, Germany, on 3 January 2002, and flew to Thumrait, Oman, with 216,000 prepared meals for American military personnel based in the region. This vast number of ready meals was transported on 375 pallets and weighed 187.5 tons. The An-225 was later contracted by the Canadian and U.S. governments to transport military supplies to the Middle East in support of coalition forces. An example of the cost of shipping cargo by An-225 was over 2 million kr. (about €266,000) for flying a chimney duct from Billund, Denmark, to Kazakhstan in 2004.
During 2016, Antonov Airlines ceased cooperation with Air Foyle and partnered with Volga-Dnepr instead. This led to the An-225's blue and yellow paint scheme, added in 2009. These matched the colors of the Ukrainian flag and led to the An-225 becoming "Ukraine's winged ambassador to the world," in the words of "The New York Times".
When the COVID-19 pandemic impacted the world in early 2020, the An-225 participated in the relief effort by conducting flights to deliver medical supplies from China to other parts of the